discontinued / server · Files

index.html 103 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML+RDFa 1.0//EN' 'http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd'>
<html dir="ltr" about="" property="dcterms:language" content="en" xmlns="http://www.w3.org/1999/xhtml" xmlns:dcterms='http://purl.org/dc/terms/' xmlns:bibo='http://purl.org/ontology/bibo/' xmlns:foaf='http://xmlns.com/foaf/0.1/' xmlns:xsd='http://www.w3.org/2001/XMLSchema#'>
<head>
<title>RDFa API</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />

<!--  
  === NOTA BENE ===
  For the three scripts below, if your spec resides on dev.w3 you can check them
  out in the same tree and use relative links so that they'll work offline,
   -->



<style type="text/css">
/*****************************************************************
 * ReSpec CSS
 * Robin Berjon (robin at berjon dot com)
 * v0.05 - 2009-07-31
 *****************************************************************/


/* --- INLINES --- */
em.rfc2119 { 
    text-transform:     lowercase;
    font-variant:       small-caps;
    font-style:         normal;
    color:              #900;
}

h1 acronym, h2 acronym, h3 acronym, h4 acronym, h5 acronym, h6 acronym, a acronym,
h1 abbr, h2 abbr, h3 abbr, h4 abbr, h5 abbr, h6 abbr, a abbr {
    border: none;
}

dfn {
    font-weight:    bold;
}

a.internalDFN {
    color:  inherit;
    border-bottom:  1px solid #99c;
    text-decoration:    none;
}

a.externalDFN {
    color:  inherit;
    border-bottom:  medium dotted #ccc;
    text-decoration:    none;
}

a.bibref {
    text-decoration:    none;
}

code {
    color:  #ff4500;
}


/* --- WEB IDL --- */
pre.idl {
    border-top: 1px solid #90b8de;
    border-bottom: 1px solid #90b8de;
    padding:    1em;
    line-height:    120%;
}

pre.idl::before {
    content:    "WebIDL";
    display:    block;
    width:      150px;
    background: #90b8de;
    color:  #fff;
    font-family:    initial;
    padding:    3px;
    font-weight:    bold;
    margin: -1em 0 1em -1em;
}

.idlType {
    color:  #ff4500;
    font-weight:    bold;
    text-decoration:    none;
}

/*.idlModule*/
/*.idlModuleID*/
/*.idlInterface*/
.idlInterfaceID {
    font-weight:    bold;
    color:  #005a9c;
}

.idlSuperclass {
    font-style: italic;
    color:  #005a9c;
}

/*.idlAttribute*/
.idlAttrType, .idlFieldType {
    color:  #005a9c;
}
.idlAttrName, .idlFieldName {
    color:  #ff4500;
}
.idlAttrName a, .idlFieldName a {
    color:  #ff4500;
    border-bottom:  1px dotted #ff4500;
    text-decoration: none;
}

/*.idlMethod*/
.idlMethType {
    color:  #005a9c;
}
.idlMethName {
    color:  #ff4500;
}
.idlMethName a {
    color:  #ff4500;
    border-bottom:  1px dotted #ff4500;
    text-decoration: none;
}

/*.idlParam*/
.idlParamType {
    color:  #005a9c;
}
.idlParamName {
    font-style: italic;
}

.extAttr {
    color:  #666;
}

/*.idlConst*/
.idlConstType {
    color:  #005a9c;
}
.idlConstName {
    color:  #ff4500;
}
.idlConstName a {
    color:  #ff4500;
    border-bottom:  1px dotted #ff4500;
    text-decoration: none;
}

/*.idlException*/
.idlExceptionID {
    font-weight:    bold;
    color:  #c00;
}

.idlTypedefID, .idlTypedefType {
    color:  #005a9c;
}

.idlRaises, .idlRaises a.idlType, .idlRaises a.idlType code, .excName a, .excName a code {
    color:  #c00;
    font-weight:    normal;
}

.excName a {
    font-family:    monospace;
}

.idlRaises a.idlType, .excName a.idlType {
    border-bottom:  1px dotted #c00;
}

.excGetSetTrue, .excGetSetFalse, .prmNullTrue, .prmNullFalse, .prmOptTrue, .prmOptFalse {
    width:  45px;
    text-align: center;
}
.excGetSetTrue, .prmNullTrue, .prmOptTrue { color:  #0c0; }
.excGetSetFalse, .prmNullFalse, .prmOptFalse { color:  #c00; }

.idlImplements a {
    font-weight:    bold;
}

dl.attributes, dl.methods, dl.constants, dl.fields {
    margin-left:    2em;
}

.attributes dt, .methods dt, .constants dt, .fields dt {
    font-weight:    normal;
}

.attributes dt code, .methods dt code, .constants dt code, .fields dt code {
    font-weight:    bold;
    color:  #000;
    font-family:    monospace;
}

.attributes dt code, .fields dt code {
    background:  #ffffd2;
}

.attributes dt .idlAttrType code, .fields dt .idlFieldType code {
    color:  #005a9c;
    background:  transparent;
    font-family:    inherit;
    font-weight:    normal;
    font-style: italic;
}

.methods dt code {
    background:  #d9e6f8;
}

.constants dt code {
    background:  #ddffd2;
}

.attributes dd, .methods dd, .constants dd, .fields dd {
    margin-bottom:  1em;
}

table.parameters, table.exceptions {
    border-spacing: 0;
    border-collapse:    collapse;
    margin: 0.5em 0;
    width:  100%;
}
table.parameters { border-bottom:  1px solid #90b8de; }
table.exceptions { border-bottom:  1px solid #deb890; }

.parameters th, .exceptions th {
    color:  #fff;
    padding:    3px 5px;
    text-align: left;
    font-family:    initial;
    font-weight:    normal;
    text-shadow:    #666 1px 1px 0;
}
.parameters th { background: #90b8de; }
.exceptions th { background: #deb890; }

.parameters td, .exceptions td {
    padding:    3px 10px;
    border-top: 1px solid #ddd;
    vertical-align: top;
}

.parameters tr:first-child td, .exceptions tr:first-child td {
    border-top: none;
}

.parameters td.prmName, .exceptions td.excName, .exceptions td.excCodeName {
    width:  100px;
}

.parameters td.prmType {
    width:  120px;
}

table.exceptions table {
    border-spacing: 0;
    border-collapse:    collapse;
    width:  100%;
}

/* --- TOC --- */
.toc a {
    text-decoration:    none;
}

a .secno {
    color:  #000;
}

/* --- TABLE --- */
table.simple {
    border-spacing: 0;
    border-collapse:    collapse;
    border-bottom:  3px solid #005a9c;
}

.simple th {
    background: #005a9c;
    color:  #fff;
    padding:    3px 5px;
    text-align: left;
}

.simple th[scope="row"] {
    background: inherit;
    color:  inherit;
    border-top: 1px solid #ddd;
}

.simple td {
    padding:    3px 10px;
    border-top: 1px solid #ddd;
}

.simple tr:nth-child(even) {
    background: #f0f6ff;
}

/* --- DL --- */
.section dd > p:first-child {
    margin-top: 0;
}

.section dd > p:last-child {
    margin-bottom: 0;
}

.section dd {
    margin-bottom:  1em;
}

.section dl.attrs dd, .section dl.eldef dd {
    margin-bottom:  0;
}

/* --- EXAMPLES --- */
pre.example {
    border-top: 1px solid #ff4500;
    border-bottom: 1px solid #ff4500;
    padding:    1em;
    margin-top: 1em;
}

pre.example::before {
    content:    "Example";
    display:    block;
    width:      150px;
    background: #ff4500;
    color:  #fff;
    font-family:    initial;
    padding:    3px;
    font-weight:    bold;
    margin: -1em 0 1em -1em;
}

/* --- EDITORIAL NOTES --- */
.issue {
    padding:    1em;
    margin: 1em 0em 0em;
    border: 1px solid #f00;
    background: #ffc;
}

.issue::before {
    content:    "Issue";
    display:    block;
    width:  150px;
    margin: -1.5em 0 0.5em 0;
    font-weight:    bold;
    border: 1px solid #f00;
    background: #fff;
    padding:    3px 1em;
}

.note {
    margin: 1em 0em 0em;
    padding:    1em;
    border: 2px solid #cff6d9;
    background: #e2fff0;
}

.note::before {
    content:    "Note";
    display:    block;
    width:  150px;
    margin: -1.5em 0 0.5em 0;
    font-weight:    bold;
    border: 1px solid #cff6d9;
    background: #fff;
    padding:    3px 1em;
}

/* --- Best Practices --- */
div.practice {
    border: solid #bebebe 1px;
    margin: 2em 1em 1em 2em;
}

span.practicelab {
    margin: 1.5em 0.5em 1em 1em;
    font-weight: bold;
    font-style: italic;
}

span.practicelab   { background: #dfffff; }

span.practicelab {
    position: relative;
    padding: 0 0.5em;
    top: -1.5em;
}

p.practicedesc {
    margin: 1.5em 0.5em 1em 1em;
}

@media screen {
    p.practicedesc {
        position: relative;
        top: -2em;
        padding: 0;
        margin: 1.5em 0.5em -1em 1em;
}

/* --- SYNTAX HIGHLIGHTING --- */
pre.sh_sourceCode {
  background-color: white;
  color: black;
  font-style: normal;
  font-weight: normal;
}

pre.sh_sourceCode .sh_keyword { color: #005a9c; font-weight: bold; }           /* language keywords */
pre.sh_sourceCode .sh_type { color: #666; }                            /* basic types */
pre.sh_sourceCode .sh_usertype { color: teal; }                             /* user defined types */
pre.sh_sourceCode .sh_string { color: red; font-family: monospace; }        /* strings and chars */
pre.sh_sourceCode .sh_regexp { color: orange; font-family: monospace; }     /* regular expressions */
pre.sh_sourceCode .sh_specialchar { color: 	#ffc0cb; font-family: monospace; }  /* e.g., \n, \t, \\ */
pre.sh_sourceCode .sh_comment { color: #A52A2A; font-style: italic; }         /* comments */
pre.sh_sourceCode .sh_number { color: purple; }                             /* literal numbers */
pre.sh_sourceCode .sh_preproc { color: #00008B; font-weight: bold; }       /* e.g., #include, import */
pre.sh_sourceCode .sh_symbol { color: blue; }                            /* e.g., *, + */
pre.sh_sourceCode .sh_function { color: black; font-weight: bold; }         /* function calls and declarations */
pre.sh_sourceCode .sh_cbracket { color: red; }                              /* block brackets (e.g., {, }) */
pre.sh_sourceCode .sh_todo { font-weight: bold; background-color: #00FFFF; }   /* TODO and FIXME */

/* Predefined variables and functions (for instance glsl) */
pre.sh_sourceCode .sh_predef_var { color: #00008B; }
pre.sh_sourceCode .sh_predef_func { color: #00008B; font-weight: bold; }

/* for OOP */
pre.sh_sourceCode .sh_classname { color: teal; }

/* line numbers (not yet implemented) */
pre.sh_sourceCode .sh_linenum { display: none; }

/* Internet related */
pre.sh_sourceCode .sh_url { color: blue; text-decoration: underline; font-family: monospace; }

/* for ChangeLog and Log files */
pre.sh_sourceCode .sh_date { color: blue; font-weight: bold; }
pre.sh_sourceCode .sh_time, pre.sh_sourceCode .sh_file { color: #00008B; font-weight: bold; }
pre.sh_sourceCode .sh_ip, pre.sh_sourceCode .sh_name { color: #006400; }

/* for Prolog, Perl... */
pre.sh_sourceCode .sh_variable { color: #006400; }

/* for LaTeX */
pre.sh_sourceCode .sh_italics { color: #006400; font-style: italic; }
pre.sh_sourceCode .sh_bold { color: #006400; font-weight: bold; }
pre.sh_sourceCode .sh_underline { color: #006400; text-decoration: underline; }
pre.sh_sourceCode .sh_fixed { color: green; font-family: monospace; }
pre.sh_sourceCode .sh_argument { color: #006400; }
pre.sh_sourceCode .sh_optionalargument { color: purple; }
pre.sh_sourceCode .sh_math { color: orange; }
pre.sh_sourceCode .sh_bibtex { color: blue; }

/* for diffs */
pre.sh_sourceCode .sh_oldfile { color: orange; }
pre.sh_sourceCode .sh_newfile { color: #006400; }
pre.sh_sourceCode .sh_difflines { color: blue; }

/* for css */
pre.sh_sourceCode .sh_selector { color: purple; }
pre.sh_sourceCode .sh_property { color: blue; }
pre.sh_sourceCode .sh_value { color: #006400; font-style: italic; }

/* other */
pre.sh_sourceCode .sh_section { color: black; font-weight: bold; }
pre.sh_sourceCode .sh_paren { color: red; }
pre.sh_sourceCode .sh_attribute { color: #006400; }

</style><link href="http://www.w3.org/StyleSheets/TR/W3C-WD" rel="stylesheet" type="text/css" charset="utf-8" /></head>

<body style="display: inherit; "><div class="head"><p><a href="http://www.w3.org/"><img width="72" height="48" src="http://www.w3.org/Icons/w3c_home" alt="W3C" /></a></p><h1 property="dcterms:title" class="title" id="title">RDFa API</h1><h2 property="bibo:subtitle" id="subtitle">An API for extracting structured data from Web documents</h2><h2 property="dcterms:issued" datatype="xsd:dateTime" content="2011-04-19T04:00:00+0000" id="w3c-working-draft-19-april-2011">W3C Working Draft 19 April 2011</h2><dl><dt>This version:</dt><dd><a href="http://www.w3.org/TR/2011/WD-rdfa-api-20110419/">http://www.w3.org/TR/2011/WD-rdfa-api-20110419/</a></dd><dt>Latest published version:</dt><dd><a href="http://www.w3.org/TR/rdfa-api/">http://www.w3.org/TR/rdfa-api/</a></dd><dt>Latest editor's draft:</dt><dd><a href="http://www.w3.org/2010/02/rdfa/sources/rdfa-api/">http://www.w3.org/2010/02/rdfa/sources/rdfa-api/</a></dd><dt>Previous version:</dt><dd><a rel="dcterms:replaces" href="http://www.w3.org/TR/2010/WD-rdfa-api-20100923/">http://www.w3.org/TR/2010/WD-rdfa-api-20100923/</a></dd><dt>Editors:</dt><dd rel="bibo:editor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://digitalbazaar.com/">Manu Sporny</a>, <a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">Digital Bazaar, Inc.</a></span>
</dd>
<dd rel="bibo:editor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Benjamin Adrian" href="http://www.dfki.uni-kl.de/~adrian/">Benjamin Adrian</a>, <a rel="foaf:workplaceHomepage" href="http://www.dfki.de/">German Research Center for Artificial Intelligence GmbH</a></span>
</dd>
<dt>Authors:</dt><dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Nathan Rixham" href="http://webr3.org/">Nathan Rixham</a>, Invited Expert</span>
</dd>
<dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Mark Birbeck" href="http://webbackplane.com/">Mark Birbeck</a>, <a rel="foaf:workplaceHomepage" href="http://webbackplane.com/">Backplane Ltd.</a></span>
</dd>
<dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Ivan Herman" href="http://www.w3.org/">Ivan Herman</a>, <a rel="foaf:workplaceHomepage" href="http://www.w3.org/">W3C</a></span>
</dd>
</dl><p>This document is also available in this non-normative format: <a href="diff-20100923.html">Diff from previous Working Draft</a>.</p><p class="copyright"><a rel="license" href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 2010-2011 <span rel="dcterms:publisher"><span typeof="foaf:Organization"><a rel="foaf:homepage" property="foaf:name" content="World Wide Web Consotrium" href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>®</sup></span></span> (<a href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.</p><hr /></div>



<div id="abstract" class="introductory section" property="dcterms:abstract" datatype="" typeof="bibo:Chapter" about="#abstract"><h2>Abstract</h2>
<p>
RDFa [<cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-CORE">RDFA-CORE</a></cite>] enables authors to publish structured information that is both 
human- and machine-readable. Concepts that have traditionally been
difficult for machines to detect, like people, places, events, music, movies, 
and recipes, are now easily marked up in Web documents. While publishing this
data is vital to the growth of 
<a href="http://en.wikipedia.org/wiki/Linked_data">Linked Data</a>, 
using the information to improve the collective utility of the Web for humankind 
is the true goal. 
To accomplish this goal, it must be simple for Web developers to extract and 
utilize structured information from a Web document. This document details such a 
mechanism; an RDFa Application Programming Interface (RDFa API) that allows 
simple extraction and usage of structured information from a Web document.
</p>

<div class="informative section" typeof="bibo:Chapter" about="#how-to-read-this-document">
<h3 id="how-to-read-this-document">How to Read this Document</h3><p><em>This section is non-normative.</em></p>

<p>
This document is a detailed specification for an <em>RDFa
API</em>. The document is primarily intended for the following audiences:
</p>
<ul>
  <li>User Agent developers that are providing a mechanism to programatically
  extract RDF data from RDFa in a host language such as XHTML+RDFa 
  [<cite><a class="bibref" rel="biblioentry" href="#bib-XHTML-RDFA">XHTML-RDFA</a></cite>], HTML+RDFa [<cite><a class="bibref" rel="biblioentry" href="#bib-HTML-RDFA">HTML-RDFA</a></cite>] or SVG Tiny 1.2 [<cite><a class="bibref" rel="biblioentry" href="#bib-SVGTINY12">SVGTINY12</a></cite>],
  </li>
  <li>DOM tool developers that want to provide a mechanism for extracting
  RDFa content via programming languages such as ECMAScript, Python, Ruby,
  or Perl, and </li>
  <li>Developers that want to understand the inner workings and design
  criteria for the RDFa API.</li>
</ul>

<p>
For those looking for an introduction to the use of RDFa, or some
real-world examples, please consult the RDFa Primer [<cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-PRIMER">RDFA-PRIMER</a></cite>].</p>

<p>
If you are not familiar with RDF, you should read about the
Resource Description Framework (RDF) [<cite><a class="bibref" rel="biblioentry" href="#bib-RDF-CONCEPTS">RDF-CONCEPTS</a></cite>] before reading this
document. The [<cite><a class="bibref" rel="biblioentry" href="#bib-RDF-CONCEPTS">RDF-CONCEPTS</a></cite>] document outlines the core data model that 
is used by RDFa to express information.</p>
  
<p>
If you are not familiar with RDFa, you should read and understand the
[<cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-CORE">RDFA-CORE</a></cite>] specification. It describes how data is encoded in host
languages using RDFa. A solid understanding of concepts in RDFa Core will 
inevitably help you understand how the RDFa API works in concert
with how the data is expressed in a host language.
</p>

<p>
If you are not familiar with the RDF API, you should read about the
Resource Description Framework Application Programming Interface
[<cite><a class="bibref" rel="biblioentry" href="#bib-RDF-API">RDF-API</a></cite>] which is the base specification for this document.
The [<cite><a class="bibref" rel="biblioentry" href="#bib-RDF-API">RDF-API</a></cite>] specification outlines fundamental programming concepts
for working with Web-based data.</p>

<p>
If you are a Web developer and are already familiar with RDF and RDFa, and 
you want to programatically extract RDFa content from documents, then you will 
find the <a href="#concept-diagram">Concept Diagram</a>  and 
<a href="#developing-with-the-api">Developing with the API</a> sections of 
most interest. It contains a handful of ECMAScript examples on how to use the 
<em>RDFa API</em>.</p>

<p>
Readers who are not familiar with the Terse RDF Triple Language [<cite><a class="bibref" rel="biblioentry" href="#bib-TURTLE">TURTLE</a></cite>] 
may want to read the specification in order to understand the
short-hand RDF notation used in some of the examples.</p>
  
<p>
This document uses the <em>Web Interface Definition Language</em> 
[<cite><a class="bibref" rel="biblioentry" href="#bib-WEBIDL">WEBIDL</a></cite>] to specify all language bindings. If you intend to implement
the <em>RDFa API</em> you should be familiar with the Web IDL language
[<cite><a class="bibref" rel="biblioentry" href="#bib-WEBIDL">WEBIDL</a></cite>].</p>

<p>
Examples may contain references to existing vocabularies and use
abbreviations in CURIEs and source code. The following is a list of all
vocabularies and their abbreviations, as used in this document:
</p>

<ul>
  <li>The <a href="http://www.w3.org/1999/02/22-rdf-syntax-ns#">RDF</a>
  vocabulary (abbreviation: <code>rdf</code>, e.g., <code>rdf:type</code>)</li>
  <li>The <a href="http://www.w3.org/2001/XMLSchema#">XSD</a>
  vocabulary (abbreviation: <code>xsd</code>, e.g., <code>xsd:integer</code>)</li>
  <li>The <a href="http://www.w3.org/2000/01/rdf-schema#">RDF
  schema</a> vocabulary (abbreviation: <code>rdfs</code>, e.g., <code>rdfs:label</code>)</li>
  <li>The <a href="http://xmlns.com/foaf/spec/">Friend-Of-A-Friend</a>
  vocabulary (abbreviation: <code>foaf</code>, e.g., <code>foaf:name</code>)</li>
</ul>

</div>
</div><div id="sotd" class="introductory section" typeof="bibo:Chapter" about="#sotd"><h2>Status of This Document</h2><p><em>This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the <a href="http://www.w3.org/TR/">W3C technical reports index</a> at http://www.w3.org/TR/.</em></p>
<p>
This document was previously published by the RDFa Working Group, whose
charter was expanded in March 2011 to include work on the RDF API in addition
to continuing work on the RDFa specifications. Due to the expansion in scope, 
the RDFa Working Group was renamed to the RDF Web Applications Working 
Group.
</p>
<p>This document was published by the <a href="http://www.w3.org/2010/02/rdfa/">RDF Web Applications Working Group</a> as a Working Draft. This document is intended to become a W3C Recommendation. If you wish to make comments regarding this document, please send them to <a href="mailto:public-rdfa-wg@w3.org">public-rdfa-wg@w3.org</a> (<a href="mailto:public-rdfa-wg-request@w3.org?subject=subscribe">subscribe</a>, <a href="http://lists.w3.org/Archives/Public/public-rdfa-wg/">archives</a>). All feedback is welcome.</p><p>Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.</p><p>This document was produced by a group operating under the <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004 W3C Patent Policy</a>. W3C maintains a <a href="http://www.w3.org/2004/01/pp-impl/44350/status" rel="disclosure">public list of any patent disclosures</a> made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential Claim(s)</a> must disclose the information in accordance with <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section 6 of the W3C Patent Policy</a>.</p></div><div id="toc" typeof="bibo:Chapter" about="#toc" class="section"><h2 class="introductory">Table of Contents</h2><ul class="toc"><li class="tocline"><a href="#introduction" class="tocxref"><span class="secno">1. </span>Introduction</a><ul class="toc"><li class="tocline"><a href="#design-considerations" class="tocxref"><span class="secno">1.1 </span>Design Considerations</a></li><li class="tocline"><a href="#goals" class="tocxref"><span class="secno">1.2 </span>Goals</a></li><li class="tocline"><a href="#concept-diagram" class="tocxref"><span class="secno">1.3 </span>Concept Diagram</a></li></ul></li><li class="tocline"><a href="#developing-with-the-api" class="tocxref"><span class="secno">2. </span>Developing with the API</a><ul class="toc"><li class="tocline"><a href="#basic-concepts" class="tocxref"><span class="secno">2.1 </span>Basic Concepts</a></li><li class="tocline"><a href="#advanced-concepts" class="tocxref"><span class="secno">2.2 </span>Advanced Concepts</a></li></ul></li><li class="tocline"><a href="#the-interfaces-specification" class="tocxref"><span class="secno">3. </span>The Interfaces Specification</a><ul class="toc"><li class="tocline"><a href="#conformance" class="tocxref"><span class="secno">3.1 </span>Conformance</a></li><li class="tocline"><a href="#projections" class="tocxref"><span class="secno">3.2 </span>Projections</a></li><li class="tocline"><a href="#the-document-interface" class="tocxref"><span class="secno">3.3 </span>The Document Interface</a></li><li class="tocline"><a href="#dom-implementation-extensions" class="tocxref"><span class="secno">3.4 </span>DOM Implementation Extensions</a></li><li class="tocline"><a href="#document-data" class="tocxref"><span class="secno">3.5 </span>Document Data</a></li><li class="tocline"><a href="#rdfa-environment" class="tocxref"><span class="secno">3.6 </span>RDFa Environment</a></li></ul></li><li class="tocline"><a href="#the-initialization-process" class="tocxref"><span class="secno">4. </span>The Initialization Process</a></li><li class="tocline"><a href="#future-discussion" class="tocxref"><span class="secno">5. </span>Future Discussion</a></li><li class="tocline"><a href="#change-history" class="tocxref"><span class="secno">A. </span>Change History</a></li><li class="tocline"><a href="#acknowledgements" class="tocxref"><span class="secno">B. </span>Acknowledgements</a></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">C. </span>References</a><ul class="toc"><li class="tocline"><a href="#normative-references" class="tocxref"><span class="secno">C.1 </span>Normative references</a></li><li class="tocline"><a href="#informative-references" class="tocxref"><span class="secno">C.2 </span>Informative references</a></li></ul></li></ul></div>


<!--  END SOTD  -->


<div class="informative section" id="introduction" typeof="bibo:Chapter" about="#introduction">


<!-- OddPage -->
<h2><span class="secno">1. </span>Introduction</h2><p><em>This section is non-normative.</em></p>

<p>
RDFa provides a means to enable machine-readable markup of structured data
in human-readable Web documents. Structured data that is contained in 
documents, such as people, films, companies, events, and so on, can provide
an added layer of information to Web Applications. The RDFa API provides a 
set of interfaces that make it easy to access structured data in Web documents.
</p>

<p>
A document that contains RDFa effectively provides two data layers. The first 
layer is the information about the document itself, such as the relationship 
between the elements, the value of its attributes, the origin of the document, 
and so on, and this information is usually provided by the Document Object 
Model, or DOM [<cite><a class="bibref" rel="biblioentry" href="#bib-DOM-LEVEL-1">DOM-LEVEL-1</a></cite>].
</p>

<p>
The second data layer comprises information provided by embedded metadata, such 
as company names, film titles, ratings, and so on, and this is usually provided 
by RDFa [<cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-CORE">RDFA-CORE</a></cite>], Microformats [<cite><a class="bibref" rel="biblioentry" href="#bib-MICROFORMATS">MICROFORMATS</a></cite>], DC-HTML, GRDDL,
or Microdata.
</p>

<p>
Whilst this embedded information could be accessed via the usual DOM interfaces
-- for example, by iterating through child elements and checking attribute 
values -- the potentially complex interrelationships between the data mean 
that it is more efficient for developers if they have direct access to the data 
after it has been extracted.
</p>

<p>
For example, a document may contain the name of a person in one section and the
phone number of the same person in another; whilst the basic DOM interfaces 
provide access to these two pieces of information through normal navigation, it 
is more convenient for authors to have these two pieces of information 
available in one object.
</p>

<p>
This specification defines the RDFa API, which may be used by developers and
Web Applications to access structured data contained in Web documents.
</p>

<div class="informative section" id="design-considerations" typeof="bibo:Chapter" about="#design-considerations">
<h3><span class="secno">1.1 </span>Design Considerations</h3><p><em>This section is non-normative.</em></p>

<p>
RDFa 1.0 [<cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-SYNTAX">RDFA-SYNTAX</a></cite>] has seen substantial growth since it became
an official W3C Recommendation in October 2008. It has seen wide
adoption among search companies, e-commerce sites, governments, and
content management systems. There are numerous interoperable
implementations and growth is expected to continue to rise with the
latest releases of RDFa 1.1 [<cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-CORE">RDFA-CORE</a></cite>], XHTML+RDFa 1.1 [<cite><a class="bibref" rel="biblioentry" href="#bib-XHTML-RDFA">XHTML-RDFA</a></cite>],
and HTML+RDFa 1.1 [<cite><a class="bibref" rel="biblioentry" href="#bib-HTML-RDFA">HTML-RDFA</a></cite>].</p>

<p>
In an effort to ensure that Web applications are able
to fully utilize RDFa, this specification outlines an API and a set of
interfaces that extract RDF data from Web documents and other document formats
that utilize RDFa. The <em>RDFa API</em> is designed with maximum
code expressiveness and ease of use in mind. Furthermore, a deep understanding 
of RDF and RDFa is not necessary in order to extract and utilize the 
structured data embedded in RDFa documents.</p>

<p>
Since there are many Web browsers and programming environments for the Web,
the rapid adoption of RDFa requires an interoperable
API that Web document designers can count on being available in all Web 
browsers. The <em>RDFa API</em> provides a uniform and developer-friendly 
interface for extracting RDFa from Web documents.</p>

<p>
Since most browser-based applications and browser extensions that
utilize Web documents are written in ECMAScript [<cite><a class="bibref" rel="biblioentry" href="#bib-ECMA-262">ECMA-262</a></cite>], the 
implementation of the <em>RDFa API</em> is primarily concerned with 
ensuring that concepts covered in this document are easily utilized 
in ECMAScript.
</p>

<p>
While ECMAScript is of primary concern, the <em>RDFa API</em>
specification is language independent and is designed such that DOM tool
developers may implement it in many of the other common Web programming 
languages such as Python, Java, Perl, and Ruby. Objects that are defined by the 
<em>RDFa API</em> are designed to work as seamlessly as possible with 
language-native types, operators, and program flow constructs.
</p>
</div>

<div id="goals" typeof="bibo:Chapter" about="#goals" class="section">
<h3><span class="secno">1.2 </span>Goals</h3>

<p>The design goals that drove the creation of the APIs that are described in 
this document are:</p>

<dl>
<dt>Ease of Use and Expressiveness</dt>
<dd>
While this should be a design goal for all APIs, special care is taken to
ensure that developers can accomplish common tasks using a minimal amount of
code. While execution speed is always an important factor to consider, it is
secondary to minimizing the amount of work a developer must perform to 
extract and use data contained in the document.
</dd>
<dt>Modularity and Pluggability</dt>
<dd>
This high-level API is part of a larger family of lower-level APIs for 
interfacing with RDF data on the Web. Special care has been taken to ensure 
that this API can be implemented without requiring the larger family of APIs. 
If the larger family of APIs is available, however, this API fits in nicely 
with those RDF APIs.
</dd>
<dt>DOM Orthogonality</dt>
<dd>
Interfaces defined on the Document should match programming
paradigms that are familiar to developers. For example, if one were to 
attempt to retrieve Element Nodes by Subject, the name of the method should
be <code>document.getElementsBySubject()</code>, which roughly mirrors the
<code>document.getElementsByClassName()</code> functionality that is a part of
[<cite><a class="bibref" rel="biblioentry" href="#bib-DOM-LEVEL-1">DOM-LEVEL-1</a></cite>].
</dd>
<dt>Native Language Constructs</dt>
<dd>
Data is exposed and processed in a way that is natural for ECMAScript and
many other Web programming languages like Python, Ruby and even C++. For 
example, <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s are exposed as native language
constructs. By ensuring that programming language constructs are considered 
in the design of the API, we ensure that the API won't fight the language 
and thus, the developer.
</dd>
<dt>CURIEs and Templates</dt>
<dd>Some of the mechanisms that underpin RDF are difficult to use in everyday
programming. For example, having to type out an entire URI is not only 
laborious for a programmer, but also error prone and overly-verbose. RDFa
Core [<cite><a class="bibref" rel="biblioentry" href="#bib-RDFA-CORE">RDFA-CORE</a></cite>] introduces the concept of a Compact URI Expression, or
CURIE. This API builds on the CURIE concept and allows URIs to be expressed 
as CURIEs. The API should also provide short-cuts that reduce the amount of
code that has to be repeated. <a class="tref" title="Projection_Template">Projection Template</a>s are one 
example of reducing repetitive code writing as it can be stored in a 
single variable and re-used when building Projetions.</dd>
</dl>
</div>

<div id="concept-diagram" typeof="bibo:Chapter" about="#concept-diagram" class="section">
<h3><span class="secno">1.3 </span>Concept Diagram</h3>

<p>
The following diagram describes the relationship between all concepts discussed
in this document. 
</p>


<!--  
It's 2010, WHY DOESN'T SVG JUST WORK!!! ~~ manu
<object data="concept-stack.svg" type="image/svg+xml" width="100%" height="53%">
   <img src="concept-stack.png" alt="The RDFa API Concept Stack" />
</object>
 -->


<!--  GAAAARRRRH! COME ON! ~~ manu
<div data-include="concept-stack.svg"></div>
 -->


<div style="margin: 0 auto; text-align: center;">
   <img style="width: 50%;" src="concept-stack.png" alt="The RDFa API Concept Stack" />
<p><strong>Concept Stack for the RDFa API and RDF API</strong></p>
</div>

<p>
The RDFa API is layered on top of concepts defined by the RDF API. The lowest
level concepts are Triples, Graphs and Projections. Triples, Graphs and 
Projections are data structures used by Web Developers to work with data 
expressed in RDF languages. Working directly with the data structures can be
cumbersome at times, such as the requirement to use absolute URIs when accessing
properties, thus Profiles are provided to support accessing the data using
compact URIs (CURIEs). Data Parsers and Data Serializers provide mechanisms to 
both read and write RDF data in a variety of RDF languages. All of these 
concepts are provided via a high-level interface called the RDF Environment.
</p>
<p>
API implementers should note that only the portions of the RDF API that are 
directly used by this API need to be implemented for a conforming RDFa API
implementation. That is, only Projections are required to be implemented 
from the RDF API for a fully conformant RDFa API implementation.
</p>
<p>
The higher-level RDFa API provides two interfaces for accessing data in the
document. Simple queries for DOM data may be performed using the Document 
interface, while more complex queries for structured data may be performed 
using the Document Data interface.
</p>
</div>

</div>

<div class="informative section" id="developing-with-the-api" typeof="bibo:Chapter" about="#developing-with-the-api">

<!-- OddPage -->
<h2><span class="secno">2. </span>Developing with the API</h2><p><em>This section is non-normative.</em></p>

<p>
The following section provides an overview of the basic RDFa API that 
developers may find most useful in day-to-day programming exercises. An
overview of the more advanced RDFa API is also provided, which may help
developers when tackling some of the more complex RDFa programming tasks.
</p>

<div class="informative section" id="basic-concepts" typeof="bibo:Chapter" about="#basic-concepts">

<h3><span class="secno">2.1 </span>Basic Concepts</h3><p><em>This section is non-normative.</em></p>

<p>
This API provides a number of interfaces to enable:
</p>

<ul>
<li>parsing Documents for RDFa metadata;</li>
<li>retrieving Elements containing RDFa metadata;</li>
<li>performing advanced queries on the Document and extracting 
application-specific <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s for use in Web Applications.</li>
</ul>

<div typeof="bibo:Chapter" about="#the-basic-api" class="section">
<h4 id="the-basic-api">The Basic API</h4>

<p>
Many web developers will find that the basic functionality provided by the
RDFa API is sufficient for day-to-day programming tasks. Since developers
typically work with object-oriented data structures, the basic API is 
geared toward building language-native objects called <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s 
and returning them to the developer.
</p>

<h4 id="retrieving-data-in-the-document">Retrieving Data in the Document</h4>

 <dl>
   <dt><code>document.data.getSubjects(optional property, optional value)</code></dt>
   <dd>Retrieves a list of all subjects expressed in the document that match
     the given arguments. If no arguments are provided, all subjects expressed
     in the document are returned.</dd>

   <dt><code>document.data.getProperties(optional subject)</code></dt>
   <dd>Retrieves a list of all properties expressed in the document that
     match the given subject. If a subject isn't provided, all properties 
     expressed in the document are returned.
   </dd>

   <dt><code>document.data.getValues(optional subject, optional property)</code></dt>
   <dd>Retrieves a list of all values expressed in the document that
     match the given subject and property. If no arguments are provided, all 
     values expressed in the document are returned.
   </dd>

   <dt><code>document.data.getProjection(subject, optional template)</code></dt>
   <dd>Retrieves a single <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> given a subject and an
     optional template. The template is used for the purposes of building the 
     Projection in an application-specific way. 
     To retrieve a <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> by a particular subject, one could do 
     the following: 
     <code>document.data.getProjection("http://example.com/people#bob")</code>.
    </dd>

   <dt><code>document.data.getProjections(optional property, optional value, optional template)</code></dt>
   <dd>Retrieves a list of <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s given an optional property
     and value to match against. A template can be provided for the purposes of 
     building the <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> in an application-specific way. To 
     retrieve a list of <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s that contain the 
     <code>foaf:name</code> property, one could do the following:
     <code>document.data.getProjections("foaf:name")</code>.
    </dd>
    
 </dl>

<h4 id="retrieving-dom-elements">Retrieving DOM Elements</h4>

 <dl>
 
    <dt><code>document.getElementsByType(type)</code></dt>
    <dd>Retrieves a list of DOM Nodes given a type to match against. The type
      is the <code>rdf:type</code> expressed in the DOM Node. The type can be
      expressed via the <code>typeof</code>, <code>rel</code>, <code>rev</code>
      or the <code>property</code> attribute.
    </dd>
    
    <dt><code>document.getElementsBySubject(subject)</code></dt>
    <dd>Retrieves a list of DOM Nodes given a subject to match against. The
      subject can be expressed via the <code>about</code>, <code>href</code>, 
      <code>src</code>, or <code>resource</code> attribute.
    </dd>
    
    <dt><code>document.getElementsByProperty(property, optional value)</code></dt>
    <dd>Retrieves a list of DOM Nodes given a property and an optional value to
      match against. Properties can be expressed via the <code>typeof</code>, 
      <code>rel</code>, <code>rev</code> or <code>property</code> attribute.
    </dd>

 </dl>

<h4 id="iri-mapping">IRI Mapping</h4>
 
 <dl>
   <dt><code>document.data.setMapping(mapping, iri)</code></dt>
   <dd>Gets and sets short-hand IRI mappings that are used by the API. These
       mappings allow values such as <code>foaf</code> to be mapped to a longer
       IRI, for example: <code>http://xmlns.com/foaf/0.1/</code>. This mapping
       ensures that when a developer specifies a compact URI like 
       <code>foaf:Person</code>, that it is expanded to
       <code>http://xmlns.com/foaf/0.1/Person</code> before it is used by the
       underlying API.</dd>
 </dl>

<h4 id="advanced-processing">Advanced Processing</h4>

 <dl>
   <dt><code>document.data.rdfa.query(query, optional template)</code></dt> 
   <dd>Retrieves an array of <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s based on a set of 
     selection criteria. The template is used to build a language-native
     object that is specific to the needs of the developer and the
     application.</dd>
 </dl>

</div>

<div typeof="bibo:Chapter" about="#using-the-basic-api" class="section">
<h4 id="using-the-basic-api">Using the Basic API</h4>

<p>
The following section uses the markup shown below to demonstrate how to extract
and use subject, properties, values and <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s using the RDFa 
API. The following markup is used for the examples in this section and is 
assumed to be served from a document located at 
<code>http://example.org/people</code>.
</p>

<pre class="example">
&lt;div prefix="foaf: http://xmlns.com/foaf/0.1/" about="#albert" typeof="foaf:Person"&gt;
  &lt;span property="foaf:name"&gt;Albert Einstein&lt;/span&gt;
&lt;/div&gt;</pre>

<div typeof="bibo:Chapter" about="#retrieving-basic-data" class="section">
<h5 id="retrieving-basic-data">Retrieving Basic Data</h5>

<p>Often, developers must determine whether or not a document contains the type
of data that they are interested in processing. The RDFa API provides a simple
mechanism to extract things like subjects, properties and values from the 
current document. The return types for subjects and properties are 
always sequences of strings. Values are typically converted into language-native
types. Strings and language-native types are used in order to make processing 
the data easier on the developer.</p>

For example to get all of the subjects expressed in a document, one can use 
the following call:<p></p>

<pre class="example">
var subjects = document.data.getSubjects();</pre>

<p>To get the list of properties for each subject retrieved above, a developer
could process each subject in a loop, like so:
</p>

<pre class="example">
for(var i = 0; i &lt; subjects.length; i++)
{
   var subject = subjects[i];
   var properties = document.data.getProperties(subject);
   // ... process the properties ...
}</pre>

<p>
To retrieve only subjects containing a particular property, such as a name 
property, a developer could do the following:
</p>

<pre class="example">
var subjectsWithNames = document.data.getSubjects("http://xmlns.com/0.1/foaf/name");</pre>

<p>
Once the subjects containing a particular property are known, queries can be
done on each subject to retrieve the values of properties:
</p>

<pre class="example">
var namedSubject = subjectsWithNames[0];
var names = document.data.getValues(namedSubject, "http://xmlns.com/0.1/foaf/name");</pre>

<p>
To retrieve all values for a particular property, such as all of the names
listed in the document, the following code could be executed:
</p>

<pre class="example">
var allNames = document.data.getValues(null, "http://xmlns.com/0.1/foaf/name");</pre>

<p>
There are many more combinations of arguments passed to the basic getter 
methods for subjects, properties and values that allow high-level querying of
data in the document. While this method of working with data may be useful to
many developers, others may want to construct this data into a more 
object-oriented view of the data. In order to support this scenario, the RDFa
API introduces <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s in the next section.
</p>

</div>

<div typeof="bibo:Chapter" about="#working-with-projections" class="section">
<h5 id="working-with-projections">Working with Projections</h5>

<h4 id="retrieving-projections-by-type">Retrieving Projections by Type</h4>

<p>A <dfn title="Projection" id="dfn-projection">Projection</dfn> is an object-oriented view of a particular subject
that is expressed in the document. For example, to get all projections that 
express people in a document, a developer can do the following:
</p>

<pre class="example">
var people = document.data.getProjections("http://www.w3.org/1999/02/22-rdf-syntax-ns#type", "http://xmlns.com/foaf/0.1/Person");</pre>

A developer can also specify short-cuts to use when specifying the URI:

<pre class="example">
document.data.setMapping("rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#type");
document.data.setMapping("foaf", "http://xmlns.com/foaf/0.1/");
var people = document.data.getProjections("rdf:type", "foaf:Person");</pre>

<h4 id="retrieving-projections-by-subject">Retrieving Projections by Subject</h4>

<p>You can also get a <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> by its subject:</p>

<pre class="example">
var albert = document.data.getProjection("http://example.org/people#albert");</pre>

<p>You can also specify a relative IRI and the document IRI will be 
automatically pre-pended:</p>

<pre class="example">
var albert = document.data.getProjection("#albert");</pre>

<h4 id="retrieving-projections-by-property">Retrieving Projections by Property</h4>

<p>You can get a list of <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s by their properties:</p>

<pre class="example">
var peopleNamedAlbert = document.data.getProjections("foaf:name", "Albert Einstein");</pre>

<h4 id="using-projections">Using Projections</h4>

<p>
You can retrieve property values from <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s like so:
</p>

<pre class="example">
var albert = document.data.getProjection("#albert");
var name = albert.get("foaf:name");</pre>

<p>You can specify values that you would like to map to a 
<a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>:</p>

<pre class="example">
var albert = document.data.getProjection("#albert", {"name": "foaf:name"});
var name = albert.name;</pre>

<div class="note">The DOM may change between calls to any of the RDFa API
data retrieval methods. These changes <em class="rfc2119" title="may">may</em> cause subsequent
calls to the same methods to return different results. As with any call against 
a DOM that is changing, developers are advised to program accordingly in order 
to avoid race conditions and other issues resulting from a changing 
data set.</div>

</div>

<div typeof="bibo:Chapter" about="#managing-elements-with-data" class="section">
<h5 id="managing-elements-with-data">Managing Elements with Data</h5>

<h4 id="retrieving-elements-containing-data-by-type">Retrieving Elements Containing Data by Type</h4>

<p>You can retrieve the DOM Element that is described above by doing the following:
</p>

<pre class="example">
var elements = document.getElementsByType("http://xmlns.com/foaf/0.1/Person");</pre>

or you can specify a short-cut to use when specifying the IRI:

<pre class="example">
document.data.setMapping("foaf", "http://xmlns.com/foaf/0.1/");
var elements = document.getElementsByType("foaf:Person");</pre>

<h4 id="retrieving-elements-containing-data-by-subject">Retrieving Elements Containing Data by Subject</h4>

<p>You can also get a list of Elements by the subject of the data:</p>

<pre class="example">
var elements = document.getElementsBySubject("http://example.org/people#albert");</pre>

<p>You can also specify a relative IRI and the document IRI will be 
automatically pre-pended:</p>

<pre class="example">
var elements = document.getElementsBySubject("#albert");</pre>

<h4 id="retrieving-elements-by-property">Retrieving Elements by Property</h4>

<p>You can get a list of Elements by the properties and values that
they declare:</p>

<pre class="example">
var elements = document.getElementsByProperty("foaf:name", "Albert Einstein");</pre>

<h4 id="modifying-dom-elements">Modifying DOM Elements</h4>

<p>
You can modify elements that are returned just like any other DOM Node, 
for example:
</p>

<pre class="example">
var elements = document.getElementsByProperty("foaf:name", "Bob");
for(i = 0; i &lt;= elements.length; i++)
{
   var e = elements[i];
   e.style.setProperty('color', '#00cc00', null);
}</pre>

<p>
The code above would change the color of all the areas of the page where the
item's name is "Bob" to green.
</p>

</div>
</div>

</div>

<div id="advanced-concepts" typeof="bibo:Chapter" about="#advanced-concepts" class="section">
<h3><span class="secno">2.2 </span>Advanced Concepts</h3>

<p>
This section covers a number of concepts that go beyond basic day-to-day 
usage of the RDFa API.
</p>

<div typeof="bibo:Chapter" about="#advanced-queries" class="section">
<h4 id="advanced-queries">Advanced Queries</h4>

<div typeof="bibo:Chapter" about="#querying-by-type" class="section">
<h5 id="querying-by-type">Querying by Type</h5>

<p>
Perhaps the most basic task is to select <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s of a
particular type. The type of a <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> is set in RDFa via
the special attribute <code>typeof</code>. For example, the following
markup expresses a <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> of type <i>Person</i> in the
Friend-of-a-Friend vocabulary:
</p>

<pre class="example">
&lt;div typeof="foaf:Person"&gt;
  &lt;span property="foaf:name"&gt;Albert Einstein&lt;/span&gt;
&lt;/div&gt;</pre>

<p>
To locate all <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s that are people, we could use the
<code>document.getProjections()</code> method:

</p><pre class="example">
document.data.getProjections("rdf:type", "foaf:Person");</pre>

or we could do the same using the standard query interface to retrieve a
<a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>:<p></p>

<pre class="example">
var people = document.data.rdfa.query({"rdf:type": "foaf:Person"}, 
   {"name": "foaf:name", "age": "foaf:age"});</pre>

<p>
While the query interface is more verbose for simple queries, it becomes
necessary for more complex queries as demonstrated later in this section. Note 
that the Query object has access to 
the mappings provided via the document.data object, so they can also be 
used in queries. It is also possible to write the same query in a way that is 
independent of any prefix-mappings:</p>

<pre class="example">
var people = document.data.rdfa.query( 
   { "http://www.w3.org/1999/02/22-rdf-syntax-ns#type": "http://xmlns.com/foaf/0.1/Person" },
   { "name": "http://xmlns.com/foaf/0.1/name", "age": "http://xmlns.com/foaf/0.1/age" });</pre>
</div>

<div typeof="bibo:Chapter" about="#querying-by-property-value" class="section">
<h5 id="querying-by-property-value">Querying by Property Value</h5>

<p>
The previous query selected all <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s of a certain
type, but it did so by indicating that the property <code>rdf:type</code>
should have a specific value. Queries can also specify other
properties. For example, given the following mark-up:
</p>

<pre class="example">
&lt;div typeof="foaf:Person"&gt;
  &lt;span property="foaf:name"&gt;Albert Einstein&lt;/span&gt; -
  &lt;span property="foaf:myersBriggs"&gt;INTP&lt;/span&gt;
  &lt;a rel="foaf:workInfoHomepage" href="http://en.wikipedia.org/wiki/Albert_Einstein"&gt;More...&lt;/span&gt;
&lt;/div&gt;
&lt;div typeof="foaf:Person"&gt;
  &lt;span property="foaf:name"&gt;Mother Teresa&lt;/span&gt; -
  &lt;span property="foaf:myersBriggs"&gt;ISFJ&lt;/span&gt;
  &lt;a rel="foaf:workInfoHomepage" href="http://en.wikipedia.org/wiki/Mother_Teresa"&gt;More...&lt;/span&gt;
&lt;/div&gt;
&lt;div typeof="foaf:Person"&gt;
  &lt;span property="foaf:name"&gt;Marie Curie&lt;/span&gt; - 
  &lt;span property="foaf:myersBriggs"&gt;INTP&lt;/span&gt;
  &lt;a rel="foaf:workInfoHomepage" href="http://en.wikipedia.org/wiki/Marie_Curie"&gt;More...&lt;/span&gt;
&lt;/div&gt;</pre>

<p>
The following query demonstrates how a developer would select and use
all <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s of type <i>Person</i> that also have a Myers Brigg's 
personality type of "INTP" (aka: The Architect):
</p>

<pre class="example">
var architects = document.data.rdfa.query({
  "http://www.w3.org/1999/02/22-rdf-syntax-ns#type": "http://xmlns.com/foaf/0.1/Person",
  "http://xmlns.com/foaf/0.1/myersBriggs": "INTP" },
  { "name": "http://xmlns.com/foaf/0.1/name" });

var name = architects[0].name;</pre>

<p>
As before, prefix-mappings can also be used:
</p>

<pre class="example">
var architects = document.data.rdfa.query( 
   { "rdf:type": "foaf:Person", "foaf:myersBriggs": "INTP" },
   { "name": "foaf:name" });

var name = architects[0].name;</pre>

In this case, all of the "INTP" personality types are gleaned from the 
page and presented as <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s containing each person's 
name and blog page:
<p></p>

<pre class="example">
var architects = document.data.rdfa.query( 
   { "rdf:type": "foaf:Person", "foaf:myersBriggs": "INTP" },
   { "name": "foaf:name", "webpage": "foaf:workInfoHomepage" });

var name = architects[0].name;
var infoWebpage = architects[0].webpage;</pre>

</div>
</div>

<div typeof="bibo:Chapter" about="#creating-projections" class="section">
<h4 id="creating-projections">Creating Projections</h4>

<p>
Developers may find that they need to be able to
build custom, language-native objects to use with their code.
These specialized language-native objects are called <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s, 
and can be built by utilizing <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> Templates.
</p>

<p class="issue">There has been a complaint that this section comes from out
of nowhere. The purpose of this section is to describe that Projections
can be mapped to native language objects to ease development. We may need to
elaborate more on this at this point in the document to help integrate
this section with the flow of the document.</p>

<p>
For example, assume our source document contains the following
event, marked up using the Data Vocabulary Event format:
</p>

<pre class="example">
&lt;div prefix="v: http://rdf.data-vocabulary.org/#" typeof="v:Event"&gt; 
  &lt;a rel="v:url" href="http://amyandtheredfoxies.example.com/events" 
     property="v:summary"&gt;Tour Info: Amy And The Red Foxies&lt;/a&gt;
  
  &lt;span rel="v:location"&gt;
  	&lt;a typeof="v:Organization" rel="v:url" href="http://www.kammgarn.de/" property="v:name"&gt;Kammgarn&lt;/a&gt;
  &lt;/span&gt;
  &lt;div rel="v:photo"&gt;&lt;img src="foxies.jpg"/&gt;&lt;/div&gt;
  &lt;span property="v:summary"&gt;Hey K-Town, Amy And The Red Foxies will rock Kammgarn in October.&lt;/span&gt;
  When: 
  &lt;span property="v:startDate" content="20091015T19:00"&gt;15. Oct., 7:00 pm&lt;/span&gt;-
  &lt;span property="v:endDate" content="20091015T21:00"&gt;9:00 pm&lt;/span&gt;
  &lt;/span&gt;

  Category: &lt;span property="v:eventType"&gt;concert&lt;/span&gt;
&lt;/div&gt;</pre>

<p>
To query for all <i>Event</i> <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s we know that we 
can do this:
</p>

<pre class="example">
var events = document.data.getProjections("rdf:type", "http://rdf.data-vocabulary.org/#Event");</pre>

<p>
However, to build a special <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> that contains the 
summary, start date and end date, we can also do this:
</p>

<pre class="example">
var events = document.data.rdfa.query(
   { "rdf:type": "http://rdf.data-vocabulary.org/#Event" },
   { "type": "rdf:type", "summary": "v:summary", 
     "start": "v:startDate", "end": "v:endDate" } );</pre>

<p>
The second parameter is a <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> Template. Each key-value pair 
specifies a <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> property to URI mapping. That is, the key 
is the name of the property to create in the <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> object. 
The value must exist in a triple, specifically as a property of the triple, in 
order to copy the the object value of the triple over to the value of the 
<a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> object's property.
</p>

<p>
For more detailed information about queries and <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s see the 
<a class="tref idlType" title="DocumentData" href="#idl-def-DocumentData"><code>DocumentData</code></a> interface.
</p>
</div>
</div>

</div>


<div class="normative section" id="the-interfaces-specification" typeof="bibo:Chapter" about="#the-interfaces-specification">

<!-- OddPage -->
<h2><span class="secno">3. </span>The Interfaces Specification</h2>

<p>
The following section contains all of the interfaces that RDFa API 
implementers are expected to provide as well as guidance to ensure that
implementations are conformant.
</p>

<div id="conformance" typeof="bibo:Chapter" about="#conformance" class="section"><h3><span class="secno">3.1 </span>Conformance</h3><p>As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.</p>
<p>The key words <em class="rfc2119" title="must">must</em>, <em class="rfc2119" title="must not">must not</em>, <em class="rfc2119" title="required">required</em>, <em class="rfc2119" title="should">should</em>, <em class="rfc2119" title="should not">should not</em>, <em class="rfc2119" title="recommended">recommended</em>, <em class="rfc2119" title="may">may</em>, and <em class="rfc2119" title="optional">optional</em> in this specification are to be interpreted as described in [<cite><a class="bibref" rel="biblioentry" href="#bib-RFC2119">RFC2119</a></cite>].</p>

<p>
Conformance requirements phrased as algorithms or specific steps may be 
implemented in any manner, so long as the end result is equivalent. 
In particular, the algorithms defined in this specification are intended to be 
easy to follow and are not necessarily intended to be performant.
</p>

<p>
User Agents may impose implementation-specific limits on otherwise unconstrained 
inputs, e.g. to prevent denial of service attacks, to guard against running 
out of memory, or to work around platform-specific limitations.
</p>

<p>
Implementations that use ECMAScript or Java to implement the APIs defined in this 
specification <em class="rfc2119" title="must">must</em> implement them in a manner consistent with the respective 
ECMAScript or Java Bindings defined in the Web IDL specification [<cite><a class="bibref" rel="biblioentry" href="#bib-WEBIDL">WEBIDL</a></cite>], 
as this specification uses that specification's terminology.
</p>

<p>
Implementations that use any other language to implement the APIs defined in this 
specification that do not have bindings defined in the Web IDL specification
should attempt to map the API as closely as possible to the implementation
language's native mechanisms and datatypes. Developers are encouraged to work
with other developers who are providing the RDFa API in the same langauge to 
ensure that RDFa API implementations are modular and easily replaceable.
</p>
  
</div>

<div class="normative section" id="projections" typeof="bibo:Chapter" about="#projections">
<h3><span class="secno">3.2 </span>Projections</h3>

<p>
The <dfn title="Projection" id="dfn-projection-1">Projection</dfn> interface is used to build language-native
objects that can be accessed in a way that is natural for the
implementation language.
</p>

<pre class="idl">
<span class="idlInterface" id="idl-def-Projection">[<span class="extAttr">NoInterfaceObject</span>]
interface <span class="idlInterfaceID">Projection</span> {
<span class="idlMethod">    <span class="idlMethType"><a>DOMString</a>[]</span> <span class="idlMethName"><a href="#widl-Projection-getProperties">getProperties</a></span> ();</span>
<span class="idlMethod">    <span class="idlMethType"><a>DOMString</a></span>   <span class="idlMethName"><a href="#widl-Projection-getSubject">getSubject</a></span> ();</span>
<span class="idlMethod">    <span class="idlMethType"><a>any getter</a></span>  <span class="idlMethName"><a href="#widl-Projection-get">get</a></span> (<span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">uriOrCurie</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>any</a>[]</span>       <span class="idlMethName"><a href="#widl-Projection-getAll">getAll</a></span> (<span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">uriOrCurie</span></span>);</span>
};</span>
</pre><div typeof="bibo:Chapter" about="#methods" class="section"><h4 id="methods">Methods</h4><dl class="methods"><dt id="widl-Projection-get"><code>get</code></dt><dd>Retrieves the first property with the given name as a language-native 
  datatype.

    

  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">uriOrCurie</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">The name of the property to retrieve. The argument can be
      either an absolute URI or a CURIE that will be resolved using the default 
      document mapping.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>any getter</a></code></div></dd><dt id="widl-Projection-getAll"><code>getAll</code></dt><dd>Retrieves the list of values for a property as an array of 
      language-native datatypes.

    

  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">uriOrCurie</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">The name of the property to retrieve. The argument can be
      either a full URI or a CURIE that will be resolved using the default 
      document mapping.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>any</a>[]</code></div></dd><dt id="widl-Projection-getProperties"><code>getProperties</code></dt><dd>Retrieves the list of properties that are available on the 
      <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>. Each property <em class="rfc2119" title="must">must</em> be an absolute URI.
  <div><em>No parameters.</em></div><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>DOMString</a>[]</code></div></dd><dt id="widl-Projection-getSubject"><code>getSubject</code></dt><dd>Retrieves the subject URI of this <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> as a string, the
    value <em class="rfc2119" title="must">must</em> be an absolute URI.
  <div><em>No parameters.</em></div><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>DOMString</a></code></div></dd></dl></div>
</div>

<div class="normative section" id="the-document-interface" typeof="bibo:Chapter" about="#the-document-interface">
<h3><span class="secno">3.3 </span>The Document Interface</h3>

<p>
The <em>RDFa API</em> is designed to provide a small, powerful
set of document-based interfaces that a developer may use to 
retrieve <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s from a Web document. 
This section focuses on the extensions necessary to the DOM environment. 
These extensions are separated into four interfaces:</p>

<ul>
  <li><a href="#document-interface-extensions">Document Interface Extensions</a> 
  — A set of basic extensions to the Document interface to help developers
  identify DOM Nodes containing structured data in Web documents.
  </li>
  <li><a href="#dom-implementation-extensions">DOM Implementation Extensions</a>
  — An extension to the DOM Implementation that allows developers to 
  query for functionality provided by the RDFa API.
  </li>
  <li><a href="#document-data">Document Data</a> — The high-level
  interface for providing access to structured data in documents.
  </li>
  <li><a href="#rdfa-environment">RDFa Environment</a> — The high-level
  interface for performing advanced queries and parsing of RDFa documents.
  </li>
</ul>

<div typeof="bibo:Chapter" about="#document-interface-extensions" class="section">
<h4 id="document-interface-extensions">Document Interface Extensions</h4>

<p>
The following section describes all of the extensions that are necessary to
enable manipulation of structured data within a Web Document.
</p>

<pre class="idl">
<span class="idlImplements"><a>Document</a> implements <a href="#idl-def-DataDocument" class="idlType"><code>DataDocument</code></a>;</span></pre><div class="idlImplementsDesc"> 
   All instances of the DOM <a>Document</a> interface <em class="rfc2119" title="must">must</em> implement 
   <a href="#idl-def-DataDocument" class="idlType"><code>DataDocument</code></a>.
</div> 

<p>The DataDocument interface provides necessary extensions to the core
DOM Document interface to enable the processing and storage of structured data.
</p>

<pre class="idl">
<span class="idlInterface" id="idl-def-DataDocument">[<span class="extAttr">Supplemental, NoInterfaceObject</span>]
interface <span class="idlInterfaceID">DataDocument</span> {
<span class="idlAttribute">    readonly attribute <span class="idlAttrType"><a href="#idl-def-DocumentData" class="idlType"><code>DocumentData</code></a></span> <span class="idlAttrName"><a href="#widl-DataDocument-data">data</a></span>;</span>
<span class="idlMethod">    <span class="idlMethType"><a>NodeList</a></span> <span class="idlMethName"><a href="#widl-DataDocument-getElementsByType">getElementsByType</a></span> (<span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">type</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>NodeList</a></span> <span class="idlMethName"><a href="#widl-DataDocument-getElementsBySubject">getElementsBySubject</a></span> (<span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">subject</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>NodeList</a></span> <span class="idlMethName"><a href="#widl-DataDocument-getElementsByProperty">getElementsByProperty</a></span> (<span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">property</span></span>, <span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a>?</span> <span class="idlParamName">value</span></span>);</span>
};</span>
</pre><div typeof="bibo:Chapter" about="#attributes" class="section"><h5 id="attributes">Attributes</h5><dl class="attributes"><dt id="widl-DataDocument-data"><code>data</code> of type <span class="idlAttrType"><a href="#idl-def-DocumentData" class="idlType"><code>DocumentData</code></a></span>, readonly</dt><dd>The <a class="tref idlType" title="DocumentData" href="#idl-def-DocumentData"><code>DocumentData</code></a> interface is useful for extracting and storing data
     that is associated with the Document.<div><em>No exceptions.</em></div></dd></dl></div><div typeof="bibo:Chapter" about="#methods-1" class="section"><h5 id="methods-1">Methods</h5><dl class="methods"><dt id="widl-DataDocument-getElementsByProperty"><code>getElementsByProperty</code></dt><dd>Retrieves a list of Nodes objects based on the value of a given property.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">property</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">A DOMString representing an IRI-based property. The string can either
    be a absolute URI or a CURIE.</td></tr><tr><td class="prmName">value</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">A DOMString representing the value to match against.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>NodeList</a></code></div></dd><dt id="widl-DataDocument-getElementsBySubject"><code>getElementsBySubject</code></dt><dd>Retrieves a NodeList consisting of Nodes that have explicitly specified
      the given subject.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">subject</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">A DOMString representing an IRI-based subject. The string can either
    be a absolute URI or a CURIE.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>NodeList</a></code></div></dd><dt id="widl-DataDocument-getElementsByType"><code>getElementsByType</code></dt><dd>Retrieves a list of Nodes based on the object type of the
     data that they specify.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">type</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">A DOMString representing an <code>rdf:type</code> to select against.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>NodeList</a></code></div></dd></dl></div>

</div>
</div>

<div class="normative section" id="dom-implementation-extensions" about="#dom-implementation-extensions" rel="bibo:affirmedBy" resource="http://www.w3.org/2010/02/rdfa/meetings/2010-08-05#resolution_2" typeof="bibo:Chapter">
<h3><span class="secno">3.4 </span>DOM Implementation Extensions</h3>

<p>
If the RDFa API is implemented in a DOM environment and a 
<code>DOMImplementation</code> interface is provided, the following
additional requirements for the <code>hasFeature()</code> method <em class="rfc2119" title="must">must</em> be
met:</p>

<pre class="idl">
<span class="idlInterface" id="idl-def-DOMImplementation">interface <span class="idlInterfaceID">DOMImplementation</span> {
<span class="idlMethod">    <span class="idlMethType"><a>boolean</a></span> <span class="idlMethName"><a href="#widl-DOMImplementation-hasFeature">hasFeature</a></span> (<span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">feature</span></span>, <span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">version</span></span>);</span>
};</span>
</pre><div typeof="bibo:Chapter" about="#methods-2" class="section"><h4 id="methods-2">Methods</h4><dl class="methods"><dt id="widl-DOMImplementation-hasFeature"><code>hasFeature</code></dt><dd>Checks to see whether or not the DOM implementation has exposed
  all of the mandatory RDFa API features specified in this specification. An 
  implementation that supports all of the mandatory features in this 
  specification <em class="rfc2119" title="must">must</em> return <code>true</code> for a feature string of
    "<code>RDFaAPI</code>" and a version string of "<code>1.1</code>".
  
  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">feature</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">The feature string to use when checking to see if the DOM environment
    exposes all of the RDFa API attributes and methods.</td></tr><tr><td class="prmName">version</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">The version string to use when checking to see if the DOM environment
    exposes all of the RDFa API attributes and methods.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>boolean</a></code></div></dd></dl></div>

</div>

<div class="normative section" id="document-data" typeof="bibo:Chapter" about="#document-data">
<h3><span class="secno">3.5 </span>Document Data</h3>

<p>
The <a class="tref idlType" title="DocumentData" href="#idl-def-DocumentData"><code>DocumentData</code></a> interface is used to access the structured data
in the document.
</p>

<pre class="idl">
<span class="idlInterface" id="idl-def-DocumentData">[<span class="extAttr">NoInterfaceObject</span>]
interface <span class="idlInterfaceID">DocumentData</span> {
<span class="idlAttribute">    attribute <span class="idlAttrType"><a>optional RDFEnvironment</a></span> <span class="idlAttrName"><a href="#widl-DocumentData-rdf">rdf</a></span>;</span>
<span class="idlAttribute">    attribute <span class="idlAttrType"><a href="#idl-def-RDFaEnvironment" class="idlType"><code>RDFaEnvironment</code></a></span>         <span class="idlAttrName"><a href="#widl-DocumentData-rdfa">rdfa</a></span>;</span>
<span class="idlMethod">    <span class="idlMethType"><a href="#idl-def-Projection" class="idlType"><code>Projection</code></a></span>            <span class="idlMethName"><a href="#widl-DocumentData-getProjection">getProjection</a></span> (<span class="idlParam">in <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">subject</span></span>, <span class="idlParam">in optional <span class="idlParamType"><a>object</a></span> <span class="idlParamName">template</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>Sequence &lt;Projection&gt;</a></span> <span class="idlMethName"><a href="#widl-DocumentData-getProjections">getProjections</a></span> (<span class="idlParam">in optional <span class="idlParamType"><a>object</a></span> <span class="idlParamName">template</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>Sequence &lt;Projection&gt;</a></span> <span class="idlMethName"><a href="#widl-DocumentData-getProjections">getProjections</a></span> (<span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a></span> <span class="idlParamName">property</span></span>, <span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a>?</span> <span class="idlParamName">value</span></span>, <span class="idlParam">in optional <span class="idlParamType"><a>object</a></span> <span class="idlParamName">template</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>Sequence&lt;DOMString&gt;</a></span>   <span class="idlMethName"><a href="#widl-DocumentData-getProperties">getProperties</a></span> (<span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a>?</span> <span class="idlParamName">subject</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>Sequence&lt;DOMString&gt;</a></span>   <span class="idlMethName"><a href="#widl-DocumentData-getSubjects">getSubjects</a></span> (<span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a>?</span> <span class="idlParamName">property</span></span>, <span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a>?</span> <span class="idlParamName">value</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>Sequence&lt;any&gt;</a></span>         <span class="idlMethName"><a href="#widl-DocumentData-getValues">getValues</a></span> (<span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a>?</span> <span class="idlParamName">subject</span></span>, <span class="idlParam">in optional <span class="idlParamType"><a>DOMString</a>?</span> <span class="idlParamName">property</span></span>);</span>
<span class="idlMethod">    <span class="idlMethType"><a>DOMString</a></span>             <span class="idlMethName"><a href="#widl-DocumentData-setMapping">setMapping</a></span> (<span class="idlParam">in <span class="idlParamType"><a>in DOMString</a></span> <span class="idlParamName">mapping</span></span>, <span class="idlParam">in <span class="idlParamType"><a>in DOMString</a></span> <span class="idlParamName">uri</span></span>);</span>
};</span>
</pre><div typeof="bibo:Chapter" about="#attributes-1" class="section"><h4 id="attributes-1">Attributes</h4><dl class="attributes"><dt id="widl-DocumentData-rdf"><code>rdf</code> of type <span class="idlAttrType"><a>optional RDFEnvironment</a></span></dt><dd>The interface to the RDF convenience methods and functionality.
  Implementations <em class="rfc2119" title="may">may</em> omit access to the underlying RDF implementation.
  If implementations include this attribute, they <em class="rfc2119" title="must">must</em> conform to the
  [<cite><a class="bibref" rel="biblioentry" href="#bib-RDF-API">RDF-API</a></cite>] specification.<div><em>No exceptions.</em></div></dd><dt id="widl-DocumentData-rdfa"><code>rdfa</code> of type <span class="idlAttrType"><a href="#idl-def-RDFaEnvironment" class="idlType"><code>RDFaEnvironment</code></a></span></dt><dd>The RDFa Environment interface provides RDFa-specific capabilities.<div><em>No exceptions.</em></div></dd></dl></div><div typeof="bibo:Chapter" about="#methods-3" class="section"><h4 id="methods-3">Methods</h4><dl class="methods"><dt id="widl-DocumentData-getProjection"><code>getProjection</code></dt><dd>Retrieves a <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> given a subject and an optional 
  Projection template if the subject exists in the document. If the subject
  does not exist in the document, <code>null</code> is returned.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">subject</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">The subject to use when matching against triples. The subject can
    be either an absolute URI or a CURIE. The subject is used
    to match against the URI in the first part of a triple. An implementation 
    <em class="rfc2119" title="must">must</em> coerce the DOMString to the same type as the triple's subject being 
    compared. If the type coercion will result in a URI, the CURIE mappings 
    <em class="rfc2119" title="must">must</em> be queried first for a mapping and the given property expanded as a 
    CURIE if a mapping is found. If the subject does not exist in the 
    document, the return value <em class="rfc2119" title="must">must</em> be <code>null</code>.</td></tr><tr><td class="prmName">template</td><td class="prmType"><code><a>object</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptTrue">✔</td><td class="prmDesc">The <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> template is used to build the return
    value. The template consists of a key-value associative array
    where the key is the name of the property to create in the 
    <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> and the value is the URI to use when matching against
    predicates in each triple.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a href="#idl-def-Projection" class="idlType"><code>Projection</code></a></code></div></dd><dt id="widl-DocumentData-getProjections"><code>getProjections</code></dt><dd>Retrieves a list of all <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s in the document using
    the optional <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> template to build the 
    <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">template</td><td class="prmType"><code><a>object</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptTrue">✔</td><td class="prmDesc">The <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> template is used to build the return
    value. The template consists of a key-value associative array
    where the key is the name of the property to create in the 
    <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> and the value is the URI to use when matching against
    predicates in each triple.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code>Sequence &lt;Projection&gt;</code></div></dd><dt id="widl-DocumentData-getProjections-2"><code>getProjections</code></dt><dd>Retrieves a list of <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s that match the given optional
    property and value, constructed using the given <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> 
    template.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">property</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptTrue">✔</td><td class="prmDesc">The property to use when matching against triples. The property can
    be either an absolute URI or a CURIE. The property is used
    to match against the URI in the second part of a triple, also known as the
    predicate. An implementation <em class="rfc2119" title="must">must</em> coerce the DOMString to the same type as
    the predicate being compared. If the type coercion will result in
    a URI, the CURIE mappings <em class="rfc2119" title="must">must</em> be queried first for a mapping and the given 
    property expanded as a CURIE if a mapping is found. If the value is
    <code>null</code>, the match is always positive.</td></tr><tr><td class="prmName">value</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">The value to use when matching against triples. The value can
    be either an absolute URI or a CURIE. The value is used to 
    match against the final part of a triple, also known as the object. An 
    implementation <em class="rfc2119" title="must">must</em> coerce the DOMString to the same type as the 
    object being compared. If the type coercion will result in a URI, the 
    CURIE mappings <em class="rfc2119" title="must">must</em> be queried first for a mapping and the given value 
    expanded as a CURIE if a mapping is found. If the value is
    <code>null</code>, the match is always positive.
    </td></tr><tr><td class="prmName">template</td><td class="prmType"><code><a>object</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptTrue">✔</td><td class="prmDesc">The <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> template is used to build the return
    value. The template consists of a key-value associative array
    where the key is the name of the property to create in the 
    <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> and the value is the URI to use when matching against
    predicates in each triple.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code>Sequence &lt;Projection&gt;</code></div></dd><dt id="widl-DocumentData-getProperties"><code>getProperties</code></dt><dd>Retrieves a list of DOMStrings which are IRI identifiers for properties
    given an optional subject to match against.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">subject</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">The subject to use when matching against triples. The subject is used
    to match against the URI in the first part of a triple. The subject can
    be either an absolute URI or a CURIE. The subject is used to 
    match against the first part of a triple. An implementation <em class="rfc2119" title="must">must</em> coerce the 
    DOMString to the same type as the triple's subject that is being compared. 
    If the type coercion will result in a URI, the CURIE mappings <em class="rfc2119" title="must">must</em> be 
    queried first for a mapping and the given property expanded as a CURIE if a 
    mapping is found. If the given subject is <code>null</code>, the match is 
    always positive.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code>Sequence &lt;DOMString&gt;</code></div></dd><dt id="widl-DocumentData-getSubjects"><code>getSubjects</code></dt><dd>Retrieves a list of DOMStrings which are IRI identifiers for subjects
    given an optional property and value to match against.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">property</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">The property to use when matching against triples. The property can
    be either an absolute URI or a CURIE. The property is used
    to match against the URI in the second part of a triple, also known as the
    predicate. An implementation <em class="rfc2119" title="must">must</em> coerce the DOMString to the same type as
    the predicate being compared. If the type coercion will result in
    a URI, the CURIE mappings <em class="rfc2119" title="must">must</em> be queried first for a mapping and the given 
    property expanded as a CURIE if a mapping is found. If the value is
    <code>null</code>, the match is always positive.</td></tr><tr><td class="prmName">value</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">The value to use when matching against triples. The value can
    be a number, a boolean, a DOMString, an absolute URI or a CURIE. The value is 
    used to match against the final part of a triple, also known as the object. 
    An implementation <em class="rfc2119" title="must">must</em> coerce the DOMString to the same type as the triple
    object being compared. If the type coercion will result in a URI, the 
    CURIE mappings <em class="rfc2119" title="must">must</em> be queried first for a mapping and the given property 
    expanded as a CURIE if a mapping is found. If the value is
    <code>null</code>, the match is always positive.
    </td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code>Sequence &lt;DOMString&gt;</code></div></dd><dt id="widl-DocumentData-getValues"><code>getValues</code></dt><dd>Retrieves a list of mixed types given an optional subject and property to
    match against.

  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">subject</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">The subject to use when matching against triples. The subject can
    be either an absolute URI or a CURIE. The subject is used
    to match against the URI in the first part of a triple. An implementation 
    <em class="rfc2119" title="must">must</em> coerce the DOMString to the same type as the subject being 
    compared. If the type coercion will result in a URI, the CURIE mappings <em class="rfc2119" title="must">must</em> 
    be queried first for a mapping and the given property expanded as a CURIE if 
    a mapping is found. If the value is <code>null</code>, the match is always 
    positive.</td></tr><tr><td class="prmName">property</td><td class="prmType"><code><a>DOMString</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">The property to use when matching against triples. The property can
    be either an absolute URI or a CURIE. The property is used
    to match against the URI in the second part of a triple, also known as the
    predicate. An implementation <em class="rfc2119" title="must">must</em> coerce the DOMString to the same type as
    the predicate being compared. If the type coercion will result in
    a URI, the CURIE mappings <em class="rfc2119" title="must">must</em> be queried first for a mapping and the given 
    property expanded as a CURIE if a mapping is found. If the value is
    <code>null</code>, the match is always positive.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code>Sequence&lt;any&gt;</code></div></dd><dt id="widl-DocumentData-setMapping"><code>setMapping</code></dt><dd>Sets a mapping given a mapping and a URI to map.
  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">mapping</td><td class="prmType"><code><a>in DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">The shortened form of the URI to map.</td></tr><tr><td class="prmName">uri</td><td class="prmType"><code><a>in DOMString</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptFalse">✘</td><td class="prmDesc">An absolute URI that the mapping should expand to when used with any
        of the structured data APIs.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code><a>DOMString</a></code></div></dd></dl></div>

</div>

<div class="normative section" id="rdfa-environment" typeof="bibo:Chapter" about="#rdfa-environment">
<h3><span class="secno">3.6 </span>RDFa Environment</h3>

<p>
The <dfn title="RDFaEnvironment" id="dfn-rdfaenvironment">RDFaEnvironment</dfn> interface is used to perform RDFa-specific
actions.
</p>

<pre class="idl">
<span class="idlInterface" id="idl-def-RDFaEnvironment">[<span class="extAttr">NoInterfaceObject</span>]
interface <span class="idlInterfaceID">RDFaEnvironment</span> {
<span class="idlMethod">    <span class="idlMethType"><a>Sequence&lt;Projection&gt;</a></span> <span class="idlMethName"><a href="#widl-RDFaEnvironment-query">query</a></span> (<span class="idlParam">in optional <span class="idlParamType"><a>object</a>?</span> <span class="idlParamName">query</span></span>, <span class="idlParam">in optional <span class="idlParamType"><a>object</a></span> <span class="idlParamName">template</span></span>);</span>
};</span>
</pre><div typeof="bibo:Chapter" about="#methods-4" class="section"><h4 id="methods-4">Methods</h4><dl class="methods"><dt id="widl-RDFaEnvironment-query"><code>query</code></dt><dd>Generates a sequence of <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a>s that match the 
  given selection criteria.
  
  <table class="parameters"><tr><th>Parameter</th><th>Type</th><th>Nullable</th><th>Optional</th><th>Description</th></tr><tr><td class="prmName">query</td><td class="prmType"><code><a>object</a></code></td><td class="prmNullTrue">✔</td><td class="prmOptTrue">✔</td><td class="prmDesc">An associative array containing properties as keys and strings to 
    match as values. If the query is null, every item in the default storage
    mechanism is returned.</td></tr><tr><td class="prmName">template</td><td class="prmType"><code><a>object</a></code></td><td class="prmNullFalse">✘</td><td class="prmOptTrue">✔</td><td class="prmDesc">A template describing the attributes to create in each 
    <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> that is returned. The template is an associative 
    array containing key-value pairs. Each key corresponds to a property that
    will be created in the Projection that is returned. Each value corresponds
    to a triple's property, also known as a predicate, whose value will be 
    stored in the <a class="tref internalDFN" title="Projection" href="#dfn-projection-1">Projection</a> as the value of the key specified in
    the template.</td></tr></table><div><em>No exceptions.</em></div><div><em>Return type: </em><code>Sequence&lt;Projection&gt;</code></div></dd></dl></div>
</div>

</div>

<div id="the-initialization-process" typeof="bibo:Chapter" about="#the-initialization-process" class="section">

<!-- OddPage -->
<h2><span class="secno">4. </span>The Initialization Process</h2>

<p>
The RDFa API <em class="rfc2119" title="must">must</em> be initialized before the Web developer has access to
any of the methods that are defined in this specification. To initialize the
API environment in a Browser-based environment, an implementor <em class="rfc2119" title="must">must</em> do the 
following:
</p>

<ol>
<li>Initialize all of the interfaces in the DOM environment required by
this specification.</li>
</ol>

Unless otherwise specified, the document base is effectively the value of 
<code>window.location.toString()</code>.

</div>

<div class="informative section" id="future-discussion" typeof="bibo:Chapter" about="#future-discussion">

<!-- OddPage -->
<h2><span class="secno">5. </span>Future Discussion</h2><p><em>This section is non-normative.</em></p>

<p>
The RDFa Working Group is currently discussing whether or not to include the
following advanced functionality: 
</p>
<ul>
<li>An event mechanism for receiving Triple modification notifications, if
changes occur in the DOM.</li>
<li>A mechanism for adding RDFa data into existing DOM content other than
the direct modification of elements to add RDFa attributes.</li>
</ul>

</div>

<div class="appendix section" id="change-history" typeof="bibo:Chapter" about="#change-history">

<!-- OddPage -->
<h2><span class="secno">A. </span>Change History</h2>
<p>The following changes have been made since the First Public Working Draft:
</p>
<ul>
  <li>Editorial changes that renamed this document to 'RDFa API' from 'RDFa DOM API'.</li>
  <li>Updated hasFeature mechanism <a href="http://www.w3.org/2010/02/rdfa/meetings/2010-08-05#resolution_2">per RDFa WG telecon discussion</a>.
  </li><li>Updated convertType mechanism <a href="http://www.w3.org/2010/02/rdfa/meetings/2010-08-05#resolution_3">per RDFa WG telecon discussion</a>.</li>
  <li>Removed 'type' from DataParser interface <a href="http://www.w3.org/2010/02/rdfa/meetings/2010-08-12#resolution_1">per RDFa telecon discussion</a>.</li>
  <li>Removed 'info' attribute from IRI, PlainLiteral, TypedLiteral and RDFTriple. 'info' attribute only exists on PropertyGroup now.</li>
  <li>Several WebIDL fixes related to <a href="http://www.w3.org/2010/02/rdfa/track/issues/33">ISSUE-33</a>.</li>
  <li>Lots of editorial updates related to <a href="http://www.w3.org/2010/02/rdfa/track/issues/28">Nathan's feedback</a>.</li>
  <li>Lots of examples updates - changed Javascript console-based
  examples as they were confusing for a variety of different reasons.
  This includes almost 50% of the example code we had, some of which
  was completely wrong because the API has changed over the last several
  months. Updated to use comments to describe what each statement does,
  added colorized comments to distinguish code more clearly.</li>
  <li>Added type parameter to createQuery - we had an example that
  specified a type, but the interface definition was missing the type
  parameter. Without this parameter, one wouldn't be able to create
  implementations that supported things like SPARQL queries.</li>
  <li>Added the DataStoreIterator callback interface as we had forgotten to
  formally define what the callback interface looks like in WebIDL.</li>
  <li>Fixed bug in the getItemsBySubject call - we were returning a
  PropertyGroupList. That didn't make any sense - you can only have one
  PropertyGroup associated with a subject since there is a 1-to-1
  mapping between subjects and PropertyGroups. We also shouldn't have
  a getItemsBySubject call - it's getItemBySubject - note the missing
  's' in Item.</li>
  <li>Fixed two CSS layout bugs in ReSpec CSS file used by RDFa API spec.</li>
  <li>Many <a href="http://lists.w3.org/Archives/Public/public-rdfa-wg/2010Sep/0066.html">updates</a> based on Ivan Hermans RDFa API review and feedback.</li>
  <li>Merged the Property Group interface into the Projection interface.</li>
  <li>Added the setMapping method to the DocumentData interface.</li>
  <li>Added the RDFa Environment interface</li>
  <li>Removed the Introductory examples as they didn't add much to the
    readability of the document.</li>
  <li>Added getSubjects(), getProperties, getValues() and renamed getItemsBy*
    to getProjection*.</li>  
</ul>
</div>

<div class="appendix section" id="acknowledgements" typeof="bibo:Chapter" about="#acknowledgements">

<!-- OddPage -->
<h2><span class="secno">B. </span>Acknowledgements</h2>

<p>
At the time of publication, the members of the RDFa Working Group
were:</p>

<ul>
<li>Ben Adida, Mozilla</li>
<li>Benjamin Adrian, German Research Center for Artificial Intelligence (DFKI) Gmbh</li>
<li>Mark Birbeck, webBackplane.com (Invited Expert)</li>
<li>Markus Gylling, DAISY Consortium</li>
<li>Ivan Herman, W3C</li>
<li>Toby Inkster (Invited Expert)</li>
<li>Shane McCarron, Applied Testing and Technology, Inc. (Invited Expert)</li>
<li>Knud Möller, DERI Galway at the National University of Ireland</li>
<li>John O'Donovan, British Broadcasting Corporation</li>
<li>Steven Pemberton, Centre for Mathematics and Computer Science (CWI)</li>
<li>Nathan Rixham (Invited Expert)</li>
<li>Manu Sporny, Digital Bazaar (Chair, Invited Expert)</li>
<li>Thomas Steiner, Google</li>
<li>Ted Thibodeau, OpenLink Software</li>
<li>Robert Weir, IBM Corporation</li>
</ul>

</div>

<!--  END s_acknowledgements  -->



<!-- 
<h1>IDL Definitions</h1>

<p>
This document contains the Web IDL definitions of the RDFa DOM
API: <a href="rdfa_dom_api.idl">rdfa_dom_api.idl</a></p>
</section>
<section class="appendix informative">
<h1>ECMAScript API Interface Example</h1>

<p>
This document contains a ECMAScript interface implementation for the RDFa 
API:<a href="rdfa_dom_api.js">rdfa_dom_api.js</a></p>
 -->





<div id="references" class="appendix section" typeof="bibo:Chapter" about="#references">
<!-- OddPage -->
<h2><span class="secno">C. </span>References</h2><div id="normative-references" typeof="bibo:Chapter" about="#normative-references" class="section"><h3><span class="secno">C.1 </span>Normative references</h3><dl class="bibliography" about=""><dt id="bib-HTML-RDFA">[HTML-RDFA]</dt><dd rel="dcterms:requires">Manu Sporny; et al. <a href="http://www.w3.org/TR/rdfa-in-html/"><cite>HTML+RDFa</cite></a> 04 March 2010. W3C Working Draft. URL: <a href="http://www.w3.org/TR/rdfa-in-html/">http://www.w3.org/TR/rdfa-in-html/</a> 
</dd><dt id="bib-RDF-API">[RDF-API]</dt><dd rel="dcterms:requires">Nathan Rixham, Manu Sporny; et al. <a href="http://www.w3.org/2010/02/rdfa/sources/rdf-api/"><cite>RDF API</cite></a> Latest. W3C Editor's Draft. URL: <a href="http://www.w3.org/2010/02/rdfa/sources/rdf-api/">http://www.w3.org/2010/02/rdfa/sources/rdf-api/</a>
</dd><dt id="bib-RDFA-CORE">[RDFA-CORE]</dt><dd rel="dcterms:requires">Shane McCarron; et al. <a href="http://www.w3.org/TR/2011/WD-rdfa-core-20110331"><cite>RDFa Core 1.1: Syntax and processing rules for embedding RDF through attributes.</cite></a>31 March 2011. W3C Working Draft. URL: <a href="http://www.w3.org/TR/2011/WD-rdfa-core-20110331">http://www.w3.org/TR/2011/WD-rdfa-core-20110331</a> 
</dd><dt id="bib-RFC2119">[RFC2119]</dt><dd rel="dcterms:requires">S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key words for use in RFCs to Indicate Requirement Levels.</cite></a> March 1997. Internet RFC 2119.  URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a> 
</dd><dt id="bib-WEBIDL">[WEBIDL]</dt><dd rel="dcterms:requires">Cameron McCormack, Sam Weinig. <a href="http://dev.w3.org/2006/webapi/WebIDL/"><cite>Web IDL</cite></a> 11 March 2010. W3C Editor's Draft. URL: <a href="http://dev.w3.org/2006/webapi/WebIDL/">http://dev.w3.org/2006/webapi/WebIDL/</a>
</dd><dt id="bib-XHTML-RDFA">[XHTML-RDFA]</dt><dd rel="dcterms:requires">Shane McCarron; et. al. <a href="http://www.w3.org/TR/2011/WD-xhtml-rdfa-20110331"><cite>XHTML+RDFa 1.1.</cite></a> 31 March 2011. W3C Working Draft. URL: <a href="http://www.w3.org/TR/2011/WD-xhtml-rdfa-20110331">http://www.w3.org/TR/2011/WD-xhtml-rdfa-20110331</a> 
</dd></dl></div><div id="informative-references" typeof="bibo:Chapter" about="#informative-references" class="section"><h3><span class="secno">C.2 </span>Informative references</h3><dl class="bibliography" about=""><dt id="bib-DOM-LEVEL-1">[DOM-LEVEL-1]</dt><dd rel="dcterms:references">Vidur Apparao; et al. <a href="http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/"><cite>Document Object Model (DOM) Level 1.</cite></a> 1 October 1998. W3C Recommendation. URL: <a href="http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/">http://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/</a> 
</dd><dt id="bib-ECMA-262">[ECMA-262]</dt><dd rel="dcterms:references"><a href="http://www.ecma-international.org/publications/standards/Ecma-262.htm"><cite>ECMAScript Language Specification, Third Edition.</cite></a> December 1999. URL: <a href="http://www.ecma-international.org/publications/standards/Ecma-262.htm">http://www.ecma-international.org/publications/standards/Ecma-262.htm</a> 
</dd><dt id="bib-MICROFORMATS">[MICROFORMATS]</dt><dd rel="dcterms:references"><a href="http://microformats.org"><cite>Microformats</cite></a>. URL: <a href="http://microformats.org">http://microformats.org</a> 
</dd><dt id="bib-RDF-CONCEPTS">[RDF-CONCEPTS]</dt><dd rel="dcterms:references">Graham Klyne; Jeremy J. Carroll. <a href="http://www.w3.org/TR/2004/REC-rdf-concepts-20040210"><cite>Resource Description Framework (RDF): Concepts and Abstract Syntax.</cite></a> 10 February 2004. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2004/REC-rdf-concepts-20040210">http://www.w3.org/TR/2004/REC-rdf-concepts-20040210</a> 
</dd><dt id="bib-RDFA-PRIMER">[RDFA-PRIMER]</dt><dd rel="dcterms:references">Mark Birbeck; Ben Adida. <a href="http://www.w3.org/TR/2008/NOTE-xhtml-rdfa-primer-20081014"><cite>RDFa Primer.</cite></a> 14 October 2008. W3C Note. URL: <a href="http://www.w3.org/TR/2008/NOTE-xhtml-rdfa-primer-20081014">http://www.w3.org/TR/2008/NOTE-xhtml-rdfa-primer-20081014</a> 
</dd><dt id="bib-RDFA-SYNTAX">[RDFA-SYNTAX]</dt><dd rel="dcterms:references">Ben Adida, et al. <a href="http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014"><cite>RDFa in XHTML: Syntax and Processing.</cite></a> 14 October 2008. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014">http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014</a> 
</dd><dt id="bib-SVGTINY12">[SVGTINY12]</dt><dd rel="dcterms:references">Scott Hayman; et al. <a href="http://www.w3.org/TR/2008/REC-SVGTiny12-20081222"><cite>Scalable Vector Graphics (SVG) Tiny 1.2 Specification.</cite></a> 22 December 2008. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2008/REC-SVGTiny12-20081222">http://www.w3.org/TR/2008/REC-SVGTiny12-20081222</a> 
</dd><dt id="bib-TURTLE">[TURTLE]</dt><dd rel="dcterms:references">David Beckett, Tim Berners-Lee. <a href="http://www.w3.org/TeamSubmission/turtle/">Turtle: Terse RDF Triple Language</a> January 2008. W3C Team Submission. URL: <a href="http://www.w3.org/TeamSubmission/turtle/">http://www.w3.org/TeamSubmission/turtle/</a> 
</dd></dl></div></div></body></html>