715994 - TreeWalker and NodeIterator not working in a page-mod content script

Status: RESOLVED WORKSFORME

(Add-on SDK Graveyard :: General, defect)

Description

[cameronmartin123]

From a page-mod content script, I cannot use TreeWalker or NodeIterator to traverse the DOM.
Here is an example content script: http://pastebin.com/xHyrPaWN

worker.nextNode() should move the pointer forward and return the current node, but it does neither. Using unsafeWindow to bypass XPCNativeWrapper doesn't change the result.
I get the same result using NodeIterator, too.

Comment 1

[Myk Melez [:myk] [@mykmelez]]

Hmm, I'm having trouble reproducing this problem.

I created a simple addon that instantiates a page mod with your example content script and applies to .org domains, then I opened http://melez.org/ in a tab, and the content script logged the following messages to the console:

    info: [object HTMLBodyElement]
     ----------
    info: [object Text]
     ----------
    info: [object Text]


Here's the addon I used to test:

    https://builder.addons.mozilla.org/addon/1003383/latest/


Do you see the same behavior when you test that addon?

Comment 2

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

Just for the record, what version of the SDK are you using to test this, Cameron?

Comment 3

[cameronmartin123]

When running Myk's Addon, I still get the same result:

info: [object HTMLBodyElement]
--------
info: null
--------
info: [object HTMLBodyElement]

I'm using SDK version 1.3 with firefox 9.0.1 on OSX.
TreeWalkers do work in normal web pages for me, so this is definitely a problem specific to the Addon SDK.

Comment 4

[cameronmartin123]

I also tried this on Firefox 9.0.1 on Ubuntu and I got the same result.

Comment 5

[Jeff Griffiths (:canuckistani) (:⚡︎)]

Interesting! I tested on 9.0.1 and got the same results as Cameron. I tested also on Aurora and got the same results as Myk. It seems like nothing is being returned by:

worker.nextNode()

...on Firefox 9. The MDN docs are regrettably sparse on Treewalker, with no docs on nextNode() and only this suggested form on the createTreeWalker page:

while(treeWalker.nextNode()) nodeList.push(treeWalker.currentNode);

Comment 6

[cameronmartin123]

@Jeff: in Firefox 9.0.1, does worker.nextNode() move the pointer forward? Do you see correct behaviour when using TreeWalker outside of the addon SDK?

Here's the W3C spec http://www.w3.org/TR/DOM-Level-2-Traversal-Range/traversal.html

Comment 7

[Jeff Griffiths (:canuckistani) (:⚡︎)]

@Cameron: very odd, I'm starting to think this is a Firefox bug in 9.0.1. I tweaked the example a little bit:

https://builder.addons.mozilla.org/addon/1032874/latest/

If I compare the behaviour of this code on 9 vs Aurora ( 11 ), they totally different:

Firefox 9:

info: []

Aurora:

info: [
   "first",
   "second",
   "third"
]

Also, if I paste the code from my version of mod.js into the scratchpad editor on Firefox 9.0.1 and run it, I get the expected output:

[
   "first",
   "second",
   "third"
]

I'll talk to the team about this tomorrow if I get some time, or failing that the Jetpack weekly meeting on Tuesday.

Comment 8

[Jeff Griffiths (:canuckistani) (:⚡︎)]

Also, Eddy and Mossop

Comment 9

[cameronmartin123]

I get the same results as you Jeff. Have you got any updates from the meeting on Tuesday?

Comment 10

[Jeff Griffiths (:canuckistani) (:⚡︎)]

Cameron: no, but that's my fault because my connection was so bad I wasn't able to participate.

Comment 11

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

Has anyone seen what this does on Firefox beta?

Comment 12

[cameronmartin123]

I get the correct behaviour in Firefox Beta.

Has anyone had any luck discovering why this bug occurs?

And has anyone tried this on Firefox 8?

Comment 13

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

Since Firefox 10 is coming out a week from Tuesday, there's not a lot we can do before then.