| <xsl:processing-instruction> | |
| Creates a processing instruction in the output document. | |
| Category | |
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Instruction |
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| Required Attributes | |
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| Optional Attributes | |
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None. |
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| Content | |
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An XSLT template. The contents of the template become the data of the processing instruction. |
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| Appears in | |
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<xsl:processing-instruction> appears inside a template. |
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| Defined in | |
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XSLT section 7.3, Creating Processing Instructions. |
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| Example | |
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We'll demonstrate a stylesheet that adds a processing instruction to an XML document. The processing instruction will associate the stylesheet
<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="xml"/>
<xsl:template match="/">
<xsl:processing-instruction name="xml-stylesheet">href="docbook/html/docbook.xsl"
type="text/xsl"</xsl:processing-instruction>
<xsl:copy-of select="."/>
</xsl:template>
</xsl:stylesheet>
This stylesheet simply uses the <xsl:copy-of> element to copy the input document to the result tree, adding a processing instruction along the way. We'll use our stylesheet with this XML document: <?xml version="1.0"?> <list> <title>A few of my favorite albums</title> <listitem>A Love Supreme</listitem> <listitem>Beat Crazy</listitem> <listitem>Here Come the Warm Jets</listitem> <listitem>Kind of Blue</listitem> <listitem>London Calling</listitem> <listitem>Remain in Light</listitem> <listitem>The Joshua Tree</listitem> <listitem>The Indestructible Beat of Soweto</listitem> </list> When we run this transformation, here are the results: <?xml version="1.0" encoding="UTF-8"?> <?xml-stylesheet href="docbook/html/docbook.xsl" type="text/xsl"?> <list> <title>A few of my favorite albums</title> <listitem>A Love Supreme</listitem> <listitem>Beat Crazy</listitem> <listitem>Here Come the Warm Jets</listitem> <listitem>Kind of Blue</listitem> <listitem>London Calling</listitem> <listitem>Remain in Light</listitem> <listitem>The Joshua Tree</listitem> <listitem>The Indestructible Beat of Soweto</listitem> </list> Note that the contents of a processing instruction are text. Even though the processing instruction we just generated looks like it contains two attributes, you can't create the processing instruction like this:
<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="xml"/>
<xsl:template match="/">
<xsl:processing-instruction name="xml-stylesheet">
<!-- This doesn't work! You can't put <xsl:attribute>
elements inside a <xsl:processing-instruction> element. -->
<xsl:attribute name="href">
<xsl:text>docbook/html/docbook.xsl</xsl:text>
</xsl:attribute>
<xsl:attribute name="type">
<xsl:text>text/xsl</xsl:text>
</xsl:attribute>
</xsl:processing-instruction>
<xsl:copy-of select="."/>
</xsl:template>
</xsl:stylesheet>
If you try this, you'll get an exception from the XSLT processor. |
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