7.5 Copying
Copying
<
copy
use-attribute-sets=
qnames
>
<-- Content: -->
<
/copy>
The xsl:copy element provides an easy way of copying
the current node. Instantiating the xsl:copy element
creates a copy of the current node. The namespace nodes of the
current node are automatically copied as well, but the attributes and
children of the node are not automatically copied. The content of the
xsl:copy element is a template for the attributes and
children of the created node; the content is instantiated only for
nodes of types that can have attributes or children (i.e. root
nodes and element nodes).
The xsl:copy element may have a
use-attribute-sets attribute (see [Named Attribute Sets]). This is used only when copying element
nodes.
The root node is treated specially because the root node of the
result tree is created implicitly. When the current node is the root
node, xsl:copy will not create a root node, but will just
use the content template.
For example, the identity transformation can be written using
xsl:copy as follows:
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
When the current node is an attribute, then if it would be an error
to use xsl:attribute to create an attribute with the same
name as the current node, then it is also an error to use
xsl:copy (see [Creating Attributes with ]).
The following example shows how xml:lang attributes
can be easily copied through from source to result. If a stylesheet
defines the following named template:
<xsl:template name="apply-templates-copy-lang">
<xsl:for-each select="@xml:lang">
<xsl:copy/>
</xsl:for-each>
<xsl:apply-templates/>
</xsl:template>
then it can simply do
<xsl:call-template name="apply-templates-copy-lang"/>
instead of
<xsl:apply-templates/>
when it wants to copy the xml:lang attribute.
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