xsl:sort

The xsl:sort element is used within an xsl:for-each or xsl:apply-templates or saxon:group element to indicate the order in which the selected elements are processed.

The select attribute (default value ".") is a string expression that calculates the sort key.

The order attribute (values "ascending" or "descending", default "ascending") determines the sort order. There is no control over language, collating sequence, or data type.

The data-type attribute determines whether collating is based on alphabetic sequence or numeric sequence. The permitted values are either "text" or "number", or a built-in type in XML Schema, such as xs:date or xs:decimal.

The collation attribute is the name of a collating sequence. If present it must be a collation URI recognized by Saxon: see Implementing a collating sequence.

The case-order attribute (values "upper-first" and "lower-first") is relevant only for data-type="text"; it determines whether uppercase letters are sorted before their lowercase equivalents, or vice-versa.

The value of the lang attribute can be an ISO language code such as "en" (English) or "de" (German). It determines the algorithm used for alphabetic collating. The default is based on the Java system locale. The value is used to select a collating sequence associated with the Java Locale for that language.

Several sort keys are allowed: they are written in major-to-minor order.

Example 1: sorting with xsl:apply-templates. This example shows a template for a BOOKLIST element which processes all the child BOOK elements in order of their child AUTHOR elements; books with the same author are in descending order of the DATE attribute.

Example 2: sorting with xsl:for-each. This example also shows a template for a BOOKLIST element which processes all the child BOOK elements in order of their child AUTHOR elements.