Check if a string is null or empty in XSLT

Question

How can I check if a value is null or empty with XSL?

For example, if categoryName is empty? I\'m using a when choosing construct.

For

Answer 1

From Empty Element:

To test if the value of a certain node is empty

It depends on what you mean by empty.

• Contains no child nodes: not(node())
• Contains no text content: not(string(.))
• Contains no text other than whitespace: not(normalize-space(.))
• Contains nothing except comments: not(node()[not(self::comment())])