CODEWITHSUNDEEP
.netxpath
toddmo
toddmo

Reputation: 22406

xpath: preceding-sibling-or-self

I'd like preceding-sibling-or-self functionality in my xpath and I'm using ../(self::*|preceding-sibling::*) and it's giving me Expression must evaluate to a node-set., so I must be doing it wrong.

This bombs no matter what context node you are on or what the xml looks like. I want to use this functionality after a / so I need the right syntax for that.

The xpath expression (self::*|preceding-sibling::*) does not give an error, so it has to do with the place in the xpath which I'm trying to use it.

EDIT:

My mistake is actually more basic. You can't even do ../(.|.) without that error. In general, I want to go to a node, then look through a set of nodes from there. The error seems to correlate with trying to use the union operator | after a slash /.

Upvotes: 5

Views: 4496

Answers (1)

toddmo
toddmo

Reputation: 22406

In XPath, if you want to use the union operator, you must use it at the beginning of the path.

(self::*|preceding-sibling::*)/Child is ok.

If you need to do Something/(self::*|preceding-sibling::*)/Child, you have to expand the left part out like this:

(Something/self::*|Something/preceding-sibling::*)/Child

Upvotes: 7

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