The xsl:attribute element is used to add an attribute value to an xsl:element element or literal result element, or to an element created using xsl:copy. The attribute must be output immediately after the element, with no intervening character data.

Category: instruction
Content: sequence-constructor
Permitted parent elements: xsl:attribute-set ; any XSLT element whose content model is sequence-constructor; any literal result element



{ qname }

Attribute name, interpreted as an attribute value template, so it may contain string expressions within curly braces. The full syntax of string expressions is outlined in XPath syntax.


{ uri }

The namespace URI of the attribute.



The attribute value may be given either by a select attribute or by an enclosed sequence constructor. If the select attribute is used and the value is a sequence, then the items in the sequence are output space-separated.


{ string }

String used to specify an alternative separator.



Indicates the data type of the value of the attribute. The value must either be a built-in type defined in XML Schema, for example xs:integer or xs:date, or a user-defined type defined in a schema imported using xsl:import-schema. Type annotations are only accessible if the attribute is added to a temporary tree that specifies validation="preserve". The value given to the attribute must be a string that conforms to the rules for the data type, as defined in XML Schema.


"strict" | "lax" | "preserve" | "strip"

Invokes validation of the contents of the attribute, by locating a global schema declaration matching the name of the attribute. (Note that attributes often have no global declaration in the schema, in which case this option is not useful. It is more common to validate attributes implicitly by validating their parent element node.)

Saxon availability

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

Notes on the Saxon implementation

Motivated by streaming, the on-empty attribute was introduced in an early Working Draft for XSLT 3.0, but later removed and replaced by the new xsl:on-empty, xsl:on-non-empty and xsl:where-populated instructions. The on-empty attribute was implemented in Saxon 9.5, but removed in 9.7.


There are two main uses for the xsl:attribute element:

The xsl:attribute must be output immediately after the relevant element is generated: there must be no intervening character data (other than whitespace which is ignored). Saxon outputs the closing ">" of the element start tag as soon as something other than an attribute is written to the output stream, and rejects an attempt to output an attribute if there is no currently-open start tag. Any special characters within the attribute value will automatically be escaped (for example, "<" will be output as "&lt;").

If two attributes are output with the same name, the second one takes precedence.


The following code creates a <FONT> element with several attributes:

<xsl:element name="FONT"> <xsl:attribute name="SIZE">4</xsl:attribute> <xsl:attribute name="FACE">Courier New</xsl:attribute> Some output text </xsl:element>

Links to W3C specifications

XSLT 2.0 Specification

XSLT 3.0 Specification

See also



literal result elements