XSLT, 2nd Edition

Name

generate-id()

Generates a unique ID (an XML name) for a given node. If no node-set is given, generate-id() generates an ID for the context node.

Syntax

[1.0] string generate-id(node-set?)
[2.0] xs:string generate-id()
[2.0] xs:string generate-id(node()?)

Inputs

[1.0] An optional node-set. If no node-set is given, this function generates an ID for the context node. If the node-set is empty, generate-id() returns an empty string.

[2.0] An optional node. If no node is given, this function generates an ID for the context node. If the argument is the empty sequence, the result is a zero-length string.

In XSLT 1.0, passing a node-set to the generate-id() function generated a unique ID for the first item in the node-set; all nodes after the first were ignored. In XSLT 2.0, it is an error to pass a sequence with more than one node to generate-id().

Output

A unique ID, or an empty string if an empty node-set is given. Several things about the generate-id() function are important to know:

• For a given transformation, every time you invoke generate-id() against a given node, the XSLT processor must return the same ID. The ID can’t change while you’re doing a transformation. If you ask the XSLT processor to transform your document with this stylesheet tomorrow, there’s no guarantee that generate-id() will generate the same ID the second time around. All of tomorrow’s calls (during one transformation) to generate-id() will generate the same ID, but that ID might not be the one generated today.

• The ...