Bug 59461 – WebKitDOMNodeList's internal order is modified when iterating it

• Status: RESOLVED
• Resolution: INVALID
• Component: WebKitGTK

[Xavier Claessens]

I have an issue when trying to implement adium theme "focus" feature in Empathy[1]

My code needs to list all nodes having "focus" in its classes, like <div class="foo focus bar"> and then remove focus from the list. So basically like this:

dom = webkit_web_view_get_dom_document (WEBKIT_WEB_VIEW (view));
nodes = webkit_dom_document_get_elements_by_class_name (dom, "focus");
for (i = 0; i < webkit_dom_node_list_get_length (nodes); i++) {

	webkit_dom_html_element_set_class_name (element, new_class_name);

}

This problem with that code is that it will update only one node op 2. My guess is that when a node is modified, it gets moved to the end of the nodes list. This seems really weird behaviour... Note that adium does exactly the same code using the MacOS objective-C API of webkit and it works as expected.


[1] https://bugzilla.gnome.org/show_bug.cgi?id=443884

[Xavier Claessens]

oohh, actually the is a small difference in adium's code, it uses querySelectorAll. And that actually work with gtk API too, like that:

nodes = webkit_dom_document_query_selector_all (dom, ".focus", NULL);

This is really confusing...

[Sam Weinig]

This is how NodeLists work in the DOM.  The ones returned from getElementsByClassName are live (http://www.whatwg.org/specs/web-apps/current-work/#dom-document-getelementsbyclassname) (meaning they update due to DOM modifications) while the ones returned from querySelectorAll (http://www.w3.org/TR/selectors-api/#queryselectorall) are static.

[Xavier Claessens]

Is that documented in the API? Feel free to close as INVALID then.

[Xan Lopez]

As Sam suggests, we just do whatever the underlying DOM implementation does, so we should be faithful to the spec here. Closing!