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<p><a href="http://www.w3.org/"><img height="48" width="72" alt=
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<h1>Document Templating Steps for XProc</h1>
<h2>W3C Working Group Note 25 January 2011</h2>
<dl>
<dt>This Version:</dt>
<dd><a href=
"http://www.w3.org/TR/2011/NOTE-xproc-template-20110125/">http://www.w3.org/TR/2011/NOTE-xproc-template-20110125/</a></dd>
<dt>Latest Version:</dt>
<dd><a href=
"http://www.w3.org/TR/xproc-template/">http://www.w3.org/TR/xproc-template/</a></dd>
<dt>Editor:</dt>
<dd><span class="personname">Norman Walsh</span>, <span class=
"orgname">MarkLogic Corporation</span> <tt class=
"email">&lt;<a href=
"mailto:norman.walsh@marklogic.com">norman.walsh@marklogic.com</a>&gt;</tt></dd>
</dl>
<p>This document is also available in these non-normative formats:
<a href="xproc-template.xml">XML</a></p>
<p class="copyright"><a href=
"http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a>
© 2011 <a href="http://www.w3.org/"><acronym title=
"World Wide Web Consortium">W3C</acronym></a><sup>®</sup> (<a href=
"http://www.csail.mit.edu/"><acronym title=
"Massachusetts Institute of Technology">MIT</acronym></a>, <a href=
"http://www.ercim.org/"><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=
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and <a href=
"http://www.w3.org/Consortium/Legal/copyright-documents">document
use</a> rules apply.</p>
<hr />
<div class="abstract">
<h2>Abstract</h2>
<p>This note describes two new XProc steps designed to make it
easier to construct documents within an XProc pipeline using values
computed by that pipeline.</p>
</div>
<div class="status">
<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 is the first publication of this document as a Working
Group Note. This document is a product of the <a href=
"http://www.w3.org/XML/Processing/">XML Processing Model Working
Group</a> as part of the W3C <a href=
"http://www.w3.org/XML/Activity">XML Activity</a>. The English
version of this specification is the only normative version.
However, for translations of this document, see <a href=
"http://www.w3.org/2003/03/Translations/byTechnology?technology=xproc-template">
http://www.w3.org/2003/03/Translations/byTechnology?technology=xproc-template</a>.</p>
<p>This Note defines some additional optional steps for use in
XProc pipelines. The XML Processing Model Working Group expects
that these new steps will be widely implemented and used.</p>
<p>Please report errors in this document to the public mailing list
<a href=
"mailto:public-xml-processing-model-comments@w3.org">public-xml-processing-model-comments@w3.org</a>
(public <a href=
"http://lists.w3.org/Archives/Public/public-xml-processing-model-comments/">
archives</a> are available).</p>
<p>Publication as a Working Group Note 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/38398/status">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>
<hr />
<div id="spectoc">
<div class="toc">
<h2 id="TableOfContents">Table of Contents</h2>
<dl class="toc">
<dt><span>1&#160;<a href=
"#introduction">Introduction</a></span></dt>
<dt><span>2&#160;<a href="#terminology">Terminology</a></span></dt>
<dt><span class="ext-optional">3&#160;<a href=
"#c.in-scope-names">p:in-scope-names</a></span></dt>
<dt><span class="ext-optional">4&#160;<a href=
"#c.template">p:template</a></span></dt>
</dl>
</div>
<h3><a name="appendices" id="appendices"></a>Appendices</h3>
<div class="toc">
<dl class="toc">
<dt><span>A&#160;<a href="#references">References</a></span></dt>
<dd>
<dl class="toc">
<dt><span>A.1&#160;<a href="#normative-references">Normative
References</a></span></dt>
</dl>
</dd>
<dt><span>B&#160;<a href="#errors-list">List of Error
Codes</a></span></dt>
<dd>
<dl class="toc">
<dt><span>B.1&#160;<a href="#app.step-errors">Step
Errors</a></span></dt>
</dl>
</dd>
</dl>
</div>
</div>
<div class="section">
<h3><a name="introduction" id=
"introduction"></a>1&#160;Introduction</h3>
<p>It's quite common in [<a href="#xproc"><span class=
"abbrev">XProc: An XML Pipeline Language</span></a>] to construct
documents using values computed by the pipeline. This is
particularly (but not exclusively) the case when the pipeline uses
the <tt class="tag-element">p:http-request</tt> step. The input to
<tt class="tag-element">p:http-request</tt> is a <tt class=
"tag-element">c:request</tt> document; attributes on the <tt class=
"tag-element">c:request</tt> element control most of the request
parameters; the body of the document forms the body of request.</p>
<p>A typical example looks like this:</p>
<div class="programlisting">
<pre>
&lt;c:request method="POST" href="http://example.com/post"
           username="user" password="password"&gt;
&lt;c:body&gt;
  &lt;computed-content/&gt;
&lt;/c:body&gt;
&lt;/c:request&gt;
</pre></div>
<p>If we assume that the <tt class="tag-attribute">href</tt> value
and the computed content come from an input document, and the
username and password are options, then a typical pipeline to
compute the request becomes quite complex.</p>
<div class="programlisting">
<pre>
&lt;p:pipeline xmlns:p="http://www.w3.org/ns/xproc"
            xmlns:c="http://www.w3.org/ns/xproc-step"
            name="main" version="1.0"&gt;
&lt;p:option name="username" required="true"/&gt;
&lt;p:option name="password" required="true"/&gt;

&lt;p:identity&gt;
  &lt;p:input port="source"&gt;
    &lt;p:inline&gt;
      &lt;c:request method="POST"/&gt;
    &lt;/p:inline&gt;
  &lt;/p:input&gt;
&lt;/p:identity&gt;

&lt;p:add-attribute match="/c:request" attribute-name="href"&gt;
  &lt;p:with-option name="attribute-value" select="/doc/request/@uri"&gt;
    &lt;p:pipe step="main" port="source"/&gt;
  &lt;/p:with-option&gt;
&lt;/p:add-attribute&gt;

&lt;p:add-attribute match="/c:request" attribute-name="username"&gt;
  &lt;p:with-option name="attribute-value" select="$username"/&gt;
&lt;/p:add-attribute&gt;

&lt;p:add-attribute match="/c:request" attribute-name="password"&gt;
  &lt;p:with-option name="attribute-value" select="$password"/&gt;
&lt;/p:add-attribute&gt;

&lt;p:insert position="first-child" match="/c:request"&gt;
  &lt;p:input port="insertion" select="/doc/request"&gt;
    &lt;p:pipe step="main" port="source"/&gt;
  &lt;/p:input&gt;
&lt;/p:insert&gt;

&lt;p:unwrap match="/c:request/request"/&gt;

&lt;/p:pipeline&gt;
</pre></div>
<p>There's nothing wrong with this pipeline, but it requires
several steps to accomplish with the pipeline author probably
considers a single operation. What's more, the result of these
steps is not immediately obvious on casual inspection.</p>
<p>In order to make this simple construction case both literally
and conceptually simpler, this note introduces two new XProc steps
in the XProc namespace. Support for these steps is optional, but we
strongly encourage implementors to provide them.</p>
<p>The new steps are <a href="#c.in-scope-names"><tt class=
"tag-element">p:in-scope-names</tt></a> and <a href=
"#c.template"><tt class="tag-element">p:template</tt></a>. Taken
together, they greatly simplify the pipeline:</p>
<div class="programlisting">
<pre>
&lt;p:pipeline xmlns:p="http://www.w3.org/ns/xproc"
            xmlns:c="http://www.w3.org/ns/xproc-step"
            name="main" version="1.0"&gt;
&lt;p:option name="username" required="true"/&gt;
&lt;p:option name="password" required="true"/&gt;

&lt;p:in-scope-names name="vars"/&gt;

&lt;p:template&gt;
  &lt;p:input port="template"&gt;
    &lt;p:inline&gt;
      &lt;c:request method="POST" href="{/doc/request/@uri}"
                 username="{$username}" password="{$password}"&gt;
        { /doc/request/node() }
      &lt;/c:request&gt;
    &lt;/p:inline&gt;
  &lt;/p:input&gt;
  &lt;p:input port="source"&gt;
    &lt;p:pipe step="main" port="source"/&gt;
  &lt;/p:input&gt;
  &lt;p:input port="parameters"&gt;
    &lt;p:pipe step="vars" port="result"/&gt;
  &lt;/p:input&gt;
&lt;/p:template&gt;

&lt;/p:pipeline&gt;
</pre></div>
<p>The <a href="#c.in-scope-names"><tt class=
"tag-element">p:in-scope-names</tt></a> step provides all of the
in-scope options and variables in a <tt class=
"tag-element">c:param-set</tt> (this operation is exactly analagous
to what the <tt class="tag-element">p:parameters</tt> step does,
except that it operates on the options and variables instead of on
parameters).</p>
<p>The <a href="#c.template"><tt class=
"tag-element">p:template</tt></a> step searches for XPath
expressions, delimited by curly braces, in a template document and
replaces each with the result of evaluating the expression. All of
the parameters passed to the <a href="#c.template"><tt class=
"tag-element">p:template</tt></a> step are available as in-scope
variable names when evaluating each XPath expression.</p>
<p>Where the expressions occur in attribute values, their string
value is used. Where they appear in text content, their node values
are used.</p>
</div>
<div class="section">
<h3><a name="terminology" id=
"terminology"></a>2&#160;Terminology</h3>
<p>In this note the words <span class="rfc2119">must</span>,
<span class="rfc2119">must not</span>, <span class=
"rfc2119">should</span>, <span class="rfc2119">should not</span>,
<span class="rfc2119">may</span> and <span class=
"rfc2119">recommended</span> are to be interpreted as described in
[<a href="#rfc2119"><span class="abbrev">RFC 2119</span></a>].</p>
</div>
<div class="section">
<h3><a name="c.in-scope-names" id=
"c.in-scope-names"></a>3&#160;p:in-scope-names</h3>
<p>The <tt class="code">p:in-scope-names</tt> step exposes all of
the in-scope variables and options as a set of parameters in a
<tt class="tag-element">c:param-set</tt> document.</p>
<p class="element-syntax element-syntax-declare-step-opt">
<span class="decl"><code>&lt;p:declare-step</code> <code class=
"attr type-attr">type</code><code>="</code><code class=
"value type-value">p:in-scope-names</code><code>"</code><code>&gt;</code></span><br />

&#160;&#160;&#160;&#160;&#160;<span class=
"input"><code>&lt;p:output</code> <code class=
"attr port-attr">port</code><code>="</code><code class=
"value port-value">result</code><code>"</code> <code class=
"attr primary-attr">primary</code><code>="</code><code class=
"value primary-value">false</code><code>"</code><code>/&gt;</code></span><br />

<code>&lt;/p:declare-step&gt;</code></p>
<p>Each in-scope variable and option is converted into a <tt class=
"tag-element">c:param</tt> element. The resulting <tt class=
"tag-element">c:param</tt> elements are wrapped in a <tt class=
"tag-element">c:param-set</tt> and the parameter set document is
written to the <tt class="port">result</tt> port. <a name="impl-1"
id="impl-1"></a>The order in which <tt class=
"tag-element">c:param</tt> elements occur in the <tt class=
"tag-element">c:param-set</tt> is <em class=
"glossterm">implementation-dependent</em>.</p>
<p>For consistency and user convenience, if any of the variables or
options have names that are in a namespace, the <tt class=
"tag-attribute">namespace</tt> attribute on the <tt class=
"tag-element">c:param</tt> element <span class=
"rfc2119">must</span> be used. Each <tt class=
"tag-attribute">name</tt> <span class="rfc2119">must</span> be an
NCName.</p>
<p>The base URI of the output document is the URI of the pipeline
document that contains the step.</p>
<p>For consistency with the <tt class=
"tag-element">p:parameters</tt> step, the <tt class=
"port">result</tt> port is not primary.</p>
<div class="section">
<h4><a name="ex-in-scope-names" id=
"ex-in-scope-names"></a>3.1&#160;Example</h4>
<p>This unlikely pipeline demonstrates the behavior of <a href=
"#c.in-scope-names"><tt class=
"tag-element">p:in-scope-names</tt></a>:</p>
<div class="programlisting">
<pre>
&lt;p:declare-step xmlns:p="http://www.w3.org/ns/xproc"
                name="main" version="1.0"&gt;
&lt;p:output port="result"&gt;
  &lt;p:pipe step="vars" port="result"/&gt;
&lt;/p:output&gt;

&lt;p:option name="username" required="true"/&gt;
&lt;p:option name="password" required="true"/&gt;
&lt;p:variable name="host" select="'http://example.com/'"/&gt;

&lt;p:in-scope-names name="vars"/&gt;

&lt;/p:declare-step&gt;
</pre></div>
<p>Assuming the values supplied for the username and password
options are “<tt class="literal">user</tt>” and “<tt class=
"literal">pass</tt>”, respectively, the output would be:</p>
<div class="programlisting">
<pre>
&lt;c:param-set xmlns:c="http://www.w3.org/ns/xproc-step"&gt;
  &lt;c:param name="username" namespace="" value="user"/&gt;
  &lt;c:param name="host" namespace="" value="http://example.com/"/&gt;
  &lt;c:param name="password" namespace="" value="pass"/&gt;
&lt;/c:param-set&gt;
</pre></div>
</div>
</div>
<div class="section">
<h3><a name="c.template" id="c.template"></a>4&#160;p:template</h3>
<p>The <tt class="code">p:template</tt> replaces each XPath
expression, delimited with curly braces, in the <tt class=
"port">template</tt> document with the result of evaluating that
expression.</p>
<p class="element-syntax element-syntax-declare-step-opt">
<span class="decl"><code>&lt;p:declare-step</code> <code class=
"attr type-attr">type</code><code>="</code><code class=
"value type-value">p:template</code><code>"</code><code>&gt;</code></span><br />

&#160;&#160;&#160;&#160;&#160;<span class=
"input"><code>&lt;p:input</code> <code class=
"attr port-attr">port</code><code>="</code><code class=
"value port-value">template</code><code>"</code><code>/&gt;</code></span><br />

&#160;&#160;&#160;&#160;&#160;<span class=
"input"><code>&lt;p:input</code> <code class=
"attr port-attr">port</code><code>="</code><code class=
"value port-value">source</code><code>"</code> <code class=
"attr sequence-attr">sequence</code><code>="</code><code class=
"value sequence-value">true</code><code>"</code> <code class=
"attr primary-attr">primary</code><code>="</code><code class=
"value primary-value">true</code><code>"</code><code>/&gt;</code></span><br />

&#160;&#160;&#160;&#160;&#160;<span class=
"input"><code>&lt;p:input</code> <code class=
"attr port-attr">port</code><code>="</code><code class=
"value port-value">parameters</code><code>"</code> <code class=
"attr kind-attr">kind</code><code>="</code><code class=
"value kind-value">parameter</code><code>"</code><code>/&gt;</code></span><br />

&#160;&#160;&#160;&#160;&#160;<span class=
"input"><code>&lt;p:output</code> <code class=
"attr port-attr">port</code><code>="</code><code class=
"value port-value">result</code><code>"</code><code>/&gt;</code></span><br />

<code>&lt;/p:declare-step&gt;</code></p>
<p>While evaluating each expression, the names of any parameters
passed to the step are available as variable values in the XPath
dynamic context.</p>
<p>The step searches for XPath expressions in attribute values,
text content (adjacent text nodes, if they occur in the data model,
must be coalesced; this step always processes maximal length text
nodes), processing instruction data, and comments. XPath
expressions are identified by curly braces, similar to attribute
value templates in XSLT or enclosed expressions in XQuery.</p>
<p>In order to allow curly braces to appear literally in content,
they can be escaped by doubling them. In other words, where
“<tt class="code">{</tt>” would start an XPath expression,
“<tt class="code">{{</tt>” is simply a <em>single</em>, literal
opening curly brace. The same applies for closing curly braces.</p>
<p>Inside an XPath expression, strings quoted by single (<tt class=
"code">'</tt>) or double (<tt class="code">"</tt>) quotes are
treated literally. Outside of quoted text, it is an error for an
opening curly brace to occur. A closing curly brace ends the XPath
expression (whether or not it is followed immediately by another
closing curly brace).</p>
<p>These parsing rules can be described by the following algorithm,
though implementations are by no means required to implement the
parsing in exactly this way, provided that they achieve the same
results.</p>
<div class="itemizedlist">
<ul>
<li>
<p>The parser begins in <em>regular-mode</em> at the start of each
unit of content where expansion may occur. In
<em>regular-mode</em>:</p>
<div class="orderedlist">
<ol style="list-style: decimal;">
<li>
<p>“<tt class="code">{{</tt>” is replaced by a single “<tt class=
"code">{</tt>”.</p>
</li>
<li>
<p>“<tt class="code">}}</tt>” is replaced by a single “<tt class=
"code">}</tt>”.</p>
<p>Note: <a name="err.inline.C0067" id="err.inline.C0067"></a>It is
a <em class="glossterm">dynamic error</em>&#160;(<a href=
"#err.C0067"><code class="errqname">err:XC0067</code></a>) to
encounter a single closing curly brace “<tt class="code">}</tt>”
that is not immediately followed by another closing curly
brace.</p>
</li>
<li>
<p>A single opening curly brace “<tt class="code">{</tt>” (not
immediately followed by another opening curly brace) is discarded
and the parser moves into <em>xpath-mode</em>. The inital
expression is empty.</p>
</li>
<li>
<p>All other characters are copied without change.</p>
</li>
</ol>
</div>
</li>
<li>
<p>In <em>xpath-mode</em>:</p>
<div class="orderedlist">
<ol style="list-style: decimal;">
<li>
<p><a name="err.inline.C0067.1" id="err.inline.C0067.1"></a>It is a
<em class="glossterm">dynamic error</em>&#160;(<a href=
"#err.C0067"><code class="errqname">err:XC0067</code></a>) to
encounter an opening curly brace “<tt class="code">{</tt>”.</p>
</li>
<li>
<p>A closing curly brace “<tt class="code">}</tt>” is discarded and
ends the expression. The expression is evaluated and the result of
that evaluation is copied to the output. The parser returns to
<em>regular-mode</em>.</p>
<p>Note: Braces cannot be escaped by doubling them in
<em>xpath-mode</em>.</p>
</li>
<li>
<p>A single quote (<tt class="code">'</tt>) is added to the current
expression and the parser moves to <em>single-quote-mode</em>.</p>
</li>
<li>
<p>A double quote (<tt class="code">"</tt>) is added to the current
expression and the parser moves to <em>double-quote-mode</em>.</p>
</li>
<li>
<p>All other characters are appended to the current expression.</p>
</li>
</ol>
</div>
</li>
<li>
<p>In <em>single-quote-mode</em>:</p>
<div class="orderedlist">
<ol style="list-style: decimal;">
<li>
<p>A single quote (<tt class="code">'</tt>) is added to the current
expression and the parser moves to <em>xpath-mode</em>.</p>
</li>
<li>
<p>All other characters are appended to the current expression.</p>
</li>
</ol>
</div>
</li>
<li>
<p>In <em>double-quote-mode</em>:</p>
<div class="orderedlist">
<ol style="list-style: decimal;">
<li>
<p>A double quote (<tt class="code">"</tt>) is added to the current
expression and the parser moves to <em>xpath-mode</em>.</p>
</li>
<li>
<p>All other characters are appended to the current expression.</p>
</li>
</ol>
</div>
</li>
</ul>
</div>
<p><a name="err.inline.C0067.2" id="err.inline.C0067.2"></a>It is a
<em class="glossterm">dynamic error</em>&#160;(<a href=
"#err.C0067"><code class="errqname">err:XC0067</code></a>) if the
parser reaches the end of the unit of content and it is not in
<em>regular-mode</em>.</p>
<p>The context node used for each expression is the document passed
on the <tt class="port">source</tt> port. <a name=
"err.inline.C0068" id="err.inline.C0068"></a>It is a <em class=
"glossterm">dynamic error</em>&#160;(<a href=
"#err.C0068"><code class="errqname">err:XC0068</code></a>) if more
than one document appears on the <tt class="port">source</tt> port.
In an XPath 1.0 implementation, if <tt class=
"tag-element">p:empty</tt> is given or implied on the <tt class=
"port">source</tt> port, an empty document node is used as the
context node. In an XPath 2.0 implementation, the context item is
undefined. <a name="err.inline.C0026" id="err.inline.C0026"></a>It
is a <em class="glossterm">dynamic error</em>&#160;(<a href=
"#err.C0026"><code class="errqname">err:XC0026</code></a>) if any
XPath expression makes reference to the context node, size, or
position when the context item is undefined.</p>
<p>In an attribute value, processing instruction, or comment, the
string value of the XPath expression is used. In text content, an
expression that selects nodes will cause those nodes to be copied
into the template document.</p>
<div class="admonition">
<div class="admon-title">Note</div>
<p>Depending on which version of XPath an implementation supports,
and possibly on the <tt class="tag-attribute">xpath-version</tt>
setting on the <tt class="tag-element">p:template</tt>, some
implementations may report errors, or different results, than other
implementations in those cases where the interpretation of an XPath
expression differs between the versions of XPath.</p>
</div>
<p>An example of <tt class="tag-element">p:document</tt> appears in
<a href="#introduction" title="Introduction">Section&#160;1,
“Introduction”</a>.</p>
</div>
<div class="appendix">
<h2><a name="references" id="references"></a>A&#160;References</h2>
<div class="section">
<h3><a name="normative-references" id=
"normative-references"></a>A.1&#160;Normative References</h3>
<div class="bibliolist">
<div class="bibliomixed" id="rfc2119">
<p>[<span class="abbrev">RFC 2119</span>] <a href=
"http://www.ietf.org/rfc/rfc2119.txt"><span class=
"citetitle"><cite>Key words for use in RFCs to Indicate Requirement
Levels</cite></span></a>. S. Bradner. Network Working Group, IETF,
Mar 1997.</p>
</div>
<div class="bibliomixed" id="xproc">
<p>[<span class="abbrev">XProc: An XML Pipeline Language</span>]
<a href="http://www.w3.org/TR/xproc/"><span class=
"citetitle"><cite>XML: An XML Pipeline Language</cite></span></a>.
Norman Walsh, Alex Milowski, and Henry S. Thompson, editors. W3C
Recommedation 11 May 2010.</p>
</div>
</div>
</div>
</div>
<div class="appendix">
<h2><a name="errors-list" id="errors-list"></a>B&#160;List of Error
Codes</h2>
<div class="section">
<h3><a name="app.step-errors" id=
"app.step-errors"></a>B.1&#160;Step Errors</h3>
<p>The following <em class="glossterm">dynamic errors</em> are
explicitly called out in this note.</p>
<div id="step-error-summary">
<h5>Step Errors</h5>
<dl class="errs">
<dt><a name="err.C0026" id="err.C0026"></a><code class=
"errqname">err:XC0026</code></dt>
<dd>
<p>It is a dynamic error if any XPath expression makes reference to
the context node, size, or position when the context item is
undefined.</p>
<p>See: <a href="#err.inline.C0026">p:template</a></p>
</dd>
<dt><a name="err.C0067" id="err.C0067"></a><code class=
"errqname">err:XC0067</code></dt>
<dd>
<p>It is a dynamic error to encounter a single closing curly brace
“}” that is not immediately followed by another closing curly
brace.</p>
<p>See: <a href="#err.inline.C0067">p:template</a>, <a href=
"#err.inline.C0067.1">p:template</a>, <a href=
"#err.inline.C0067.2">p:template</a></p>
</dd>
<dt><a name="err.C0068" id="err.C0068"></a><code class=
"errqname">err:XC0068</code></dt>
<dd>
<p>It is a dynamic error if more than one document appears on the
source port.</p>
<p>See: <a href="#err.inline.C0068">p:template</a></p>
</dd>
</dl>
</div>
<p>Other errors may also arise, see [<a href="#xproc"><span class=
"abbrev">XProc: An XML Pipeline Language</span></a>] for a complete
discussion of error codes.</p>
</div>
</div>
</div>
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