xsl:variable

Used to declare a variable and give it a value. If it appears at the top level (immediately within xsl:stylesheet) it declares a global variable, otherwise it declares a local variable that is visible only within the stylesheet element containing the xsl:variable declaration. The value of a variable can be referenced within an expression using the syntax $name.

Category: declaration
Category: instruction
Content: sequence-constructor
Permitted parent elements: xsl:package ; xsl:stylesheet ; xsl:transform ; xsl:override ; xsl:function ; any XSLT element whose content model is sequence-constructor; any literal result element

Attributes

`name`	`eqname`	Defines the name of the variable.
`select?`	`expression`	The value of the variable may be defined either by an expression within the optional `select` attribute, or by the contents of the `xsl:variable` element. In the latter case the result is a temporary tree. A temporary tree can be used like a source document, for example it can be accessed using path expressions and processed using template rules.
`as?`	`sequence-type`	Defines the required type of the variable. The supplied value of the variable will be converted to this type if required.
`static?`	`boolean`	The value `yes` may be specified only for global variables (not local variables), and indicates that the variable is a static variable (that is, its value is known during static analysis of the stylesheet). The default is `no`.
`visibility?`	`"public" \| "private" \| "final" \| "abstract"`	New in XSLT 3.0. Allowed only for global variables (not local variables). Determines the potential visibility of the component corresponding to this variable; the default is `private`.
`saxon:as?`	`sequence-type`	Allows additional type information to be supplied using Saxon extension syntax. For details see saxon:as.
`saxon:assignable?`	`boolean`	May be set on global variables. Setting the value to `yes` ensures that the variable is actually evaluated, which is useful if the `select` expression calls extension functions with side-effects; without this, a variable that is never referenced may never be evaluated. For details see saxon:assignable.

Notes on the Saxon implementation

In standard XSLT, variables once declared cannot be updated. Saxon however provides a saxon:assign extension element to circumvent this restriction. The extension attribute saxon:assignable must be set to yes on the xsl:variable in order to use this feature.

Examples

<xsl:variable name="title">A really exciting document</xsl:variable> <xsl:variable name="backcolor" expr="'#FFFFCC'" /> <xsl:template match="/*"> <HTML><TITLE><xsl:value-of select="$title"/></TITLE> <BODY BGCOLOR='{$backcolor}'> ... </BODY></HTML> </xsl:template>

Links to W3C specifications

XSLT 2.0 Specification

XSLT 3.0 Specification