Zvon XSLT Tutorial

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Quite often several templates match the same element in XML source. It must be therefore decided which one should be used. This priority order can be specified with the priority attributte. If this attribute is not specified, its priority is calculated according to several rules. XSLT stylesheet 1 and XSLT stylesheet 2 differ by priority of their templates. XSLT stylesheet 3 shows the default action in the absence of priority attributes. Template CCC has lower priority than CCC/CCC, as it is less specific. Compare XSLT stylesheet 4 and XSLT stylesheet 5 . Template CCC has lower priority than both CCC/CCC or AAA/CCC/CCC, but the latest two have the same priority. In such a case an XSLT processor may signal the error; if it does not signal an error, it must recover by choosing, from amongst the matching template rules that are left, the one that occurs last in the stylesheet. In XSLT stylesheet 6 less specific "*" has lower priority than CCC. Computed priorities ranges from -0.5 to 0.5. XSLT specification gives more details.

XSLT stylesheet 1

XML Source

Output

HTML view

CCC (id=c1)

CCC (id=c2)

CCC (id=c3)

XSLT stylesheet

<xsl:stylesheet version = '1.0'
     xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>

<xsl:template match="/">
     <xsl:apply-templates select="//CCC"/>
</xsl:template>

<xsl:template match="CCC" priority="3">
     <h3 style="color:blue">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h3>
</xsl:template>

<xsl:template match="CCC/CCC" priority="4">
     <h2 style="color:red">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h2>
</xsl:template>

</xsl:stylesheet>

XSLT stylesheet 2

XML Source

Output

HTML view

CCC (id=c1)

CCC (id=c2)

CCC (id=c3)

XSLT stylesheet

<xsl:stylesheet version = '1.0'
     xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>

<xsl:template match="/">
     <xsl:apply-templates select="//CCC"/>
</xsl:template>

<xsl:template match="CCC" priority="4">
     <h3 style="color:blue">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h3>
</xsl:template>

<xsl:template match="CCC/CCC" priority="3">
     <h2 style="color:red">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h2>
</xsl:template>

</xsl:stylesheet>

XSLT stylesheet 3

XML Source

Output

HTML view

CCC (id=c1)

CCC (id=c2)

CCC (id=c3)

XSLT stylesheet

<xsl:stylesheet version = '1.0'
     xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>

<xsl:template match="/">
     <xsl:apply-templates select="//CCC"/>
</xsl:template>

<xsl:template match="CCC">
     <h3 style="color:blue">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h3>
</xsl:template>

<xsl:template match="CCC/CCC">
     <h2 style="color:red">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h2>
</xsl:template>

</xsl:stylesheet>

XSLT stylesheet 4

XML Source

Output

HTML view

CCC (id=c1)

CCC (id=c2)

CCC (id=c3)

XSLT stylesheet

<xsl:stylesheet version = '1.0'
     xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>

<xsl:template match="/">
     <xsl:apply-templates select="//CCC"/>
</xsl:template>

<xsl:template match="CCC">
     <h3 style="color:blue">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h3>
</xsl:template>

<xsl:template match="CCC/CCC">
     <h2 style="color:red">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h2>
</xsl:template>

<xsl:template match="AAA/CCC/CCC">
     <h2 style="color:green">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h2>
</xsl:template>

</xsl:stylesheet>

XSLT stylesheet 5

XML Source

Output

HTML view

CCC (id=c1)

CCC (id=c2)

CCC (id=c3)

XSLT stylesheet

<xsl:stylesheet version = '1.0'
     xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>

<xsl:template match="/">
     <xsl:apply-templates select="//CCC"/>
</xsl:template>

<xsl:template match="CCC">
     <h3 style="color:blue">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h3>
</xsl:template>

<xsl:template match="AAA/CCC/CCC">
     <h2 style="color:green">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h2>
</xsl:template>

<xsl:template match="CCC/CCC">
     <h2 style="color:red">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h2>
</xsl:template>

</xsl:stylesheet>

XSLT stylesheet 6

XML Source

Output

HTML view

CCC (id=c1)

CCC (id=c2)

CCC (id=c3)

AAA (id=a1)

AAA (id=a2)

XSLT stylesheet

<xsl:stylesheet version = '1.0'
     xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>

<xsl:template match="/">
     <xsl:apply-templates select="//CCC"/>
     <xsl:apply-templates select="//AAA"/>
</xsl:template>

<xsl:template match="CCC">
     <h3 style="color:blue">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h3>
</xsl:template>

<xsl:template match="*">
     <h3 style="color:maroon">
          <xsl:value-of select="name()"/>
          <xsl:text> (id=</xsl:text>
          <xsl:value-of select="@id"/>
          <xsl:text>)</xsl:text>
     </h3>
</xsl:template>

</xsl:stylesheet>