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.

Saxon availability

Available in XSLT 1.0 and later versions. Available in all Saxon editions. Available for all platforms.

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