Re: document.evaluate, 2nd parameter, I don't get it

On 8/17/07, [email protected] <[email protected]> wrote:
> I'd like to get all the links inside all the subsections of the page:
> http://www.hardware.fr
> The subsections are named 'cat1', 'cat2', etc, up to 'cat16'.
> [...]
>   allLinks = document.evaluate('//a[@href]',
> document.getElementById('cat16'), null,
[...]
> returns all the links of the page, not the links of the 'cat16'
> element. Why ?
>
> Ie, it has the same results than
>   allLinks = document.evaluate('//a[@href]', document, null,
> XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
>
See http://www.w3.org/TR/xpath#path-abbrev

"//para selects all the para descendants of the document root and thus
selects all para elements in the same document as the context node"

".//para selects the para element descendants of the context node"

The "context node" is what you specify in the second parameter to
document.evaluate. This means you need .//a[@href]

> According to this page:
> http://diveintogreasemonkey.org/patterns/match-attribute.html
> it shouldn't:
> Quote:
> "The second parameter can be any element, and the XPath query will
> only return nodes that are children of that element. So if you already
> have a reference to an element (say, from document.getElementById or a
> member of a document.getElementsByTagName array), you can restrict the
> query to search only children of that element."
>
As far as I can see, this is wrong. Please let Mark know about it.

Nickolay