Bug Tracker

Ticket #13265 (closed bug: fixed)

Opened 2 years ago

Last modified 19 months ago

parent method fails with text nodes in IE10

Reported by: markrendle Owned by: dmethvin
Priority: high Milestone: 1.10/2.0
Component: traversing Version: 2.0b1
Keywords: Cc: orkel
Blocking: Blocked by:

Description

In earlier versions of jQuery, the parent method looked like this:

parent: function (elem) {

var parent = elem.parentNode; return parent && parent.nodeType !== 11 ? parent : null;

}

In 2.0.0b1, it looks like this:

parent: function (elem) {

return elem.parentElement;

}

In IE10, it seems text nodes are not elements, and do not have the parentElement property, so parent() returns undefined.

Change History

comment:1 Changed 23 months ago by dmethvin

  • Cc markelog added
  • Owner set to markrendle
  • Status changed from new to pending

Do you have a test case for this? Did you encounter it in real code? I can kind of see how it might happen if you used something like .contents() although we generally don't provide full support for text nodes in a jQuery set.

comment:2 Changed 23 months ago by gibson042

  • Priority changed from undecided to high
  • Status changed from pending to open
  • Component changed from unfiled to traversing

 http://jsfiddle.net/ZH8em/

I'm inclined to make the same argument here as elsewhere; that text nodes should generally be considered valid input for traversing methods.

comment:3 Changed 23 months ago by gibson042

It turns out that satisfying my position would require reverting much of  https://github.com/jquery/jquery/commit/65bdfbf07f911d5014e32ab126ef0c568c22bf49 (even Chrome doesn't define *ElementSibling on text nodes). Looks like it's judgment time for official support/non-support.

comment:4 Changed 23 months ago by markrendle

I did encounter this issue in real code; it happens in AngularJS's compile phase, which seems to include the newlines between divs as text nodes with value "\n". It works fine with jQuery 1.9 and earlier, and in Chrome and Firefox with 2.0.

comment:5 Changed 23 months ago by dmethvin

Man that's just sad. I guess we'll have to back out a lot of those 2.0 optimizations because our users can't easily avoid having text nodes in the set and it doesn't make sense to fork the logic.

comment:6 Changed 23 months ago by markelog

Let's look at documentation for  jQuery#parent

Get the parent of each element in the current set of matched elements, optionally filtered by a selector.

and

Given a jQuery object that represents a set of DOM elements, the .parent() method allows us to search through the parents of these elements...

If you look at documentation for others traversal methods you can find the same quotes. Text nodes, comments, document fragments, etc; aren't  elements nodes.

even Chrome doesn't define *ElementSibling on text nodes

This is logical, how can, say, nextElementSibling property, on text node, can return element node, if text node is not an element? How can it be "next element" if current node is not an element? Same logic applies to jQuery traversal methods – if, say, jQuery#nextAll, return only element nodes, current node should be an element, because we search the next elements relative to the current element. Otherwise jQuery#nextAll called on text node should return next text nodes, but not an element nodes.

This is why, say, parentElement prop on element, doesn't return document fragment node (if it's immediate parent), jQuery#parent, doesn't return it too.

What is bad, that behavior in 2.0 differ from 1.9, but differ or not, jQuery does not, generally, support  them, nor data module, nor events and etc; are not fully (or entirely) support them too, same goes for other node types, i think we don't have tests for them, for that reason, 1.9 traversal methods called on text node situation is just a side effect of jQuery#contents.

Given by limited use cases, and hit on size (although not big) and perfomance, i say we should stick to W3C specification and our documentation.

That being said, we might make an exception for jQuery#parent, this is more or less in line with the existing logic, although contradicts our documentation, but i would not hurry with such decision, we might just wait for other examples, if it really widespreaded, others tickets should pop up.

comment:7 Changed 23 months ago by gibson042

We've always suffered a backhanded treatment of text nodes, but methods like .contents, parseHTML, and even jQuery itself are explicit about putting them in collections. I took the position last year that we should stop carving out exceptions piecemeal for things like .has and .parent, and accept them as valid input (though generally not output) for traversing methods (specifically excluding other modules). As it turns out, we were already pretty solid on this point, but unfortunately it wasn't secured by unit tests—which is how we got here.

But either way, I think the time has come for a clear stance, preferably expressible in a single line of copypasta.

comment:8 Changed 23 months ago by markelog

Traversal module is basically representation of Element Traversal API, it always has been, documentation is explicit about what input and output should be, just like W3C-specification about definition of what element is, it's pretty clear stance i would say.

There are some exceptions, but i think not in this case, for text node, it's logical that it might have parent element. But it's not logical to ask for previous element from a text node if user does not have current element node, but only text node, this is not semantically correct.

If we excluding other modules and we are and we should, leaving only traversal module for that equation it would look as exception to me.

comment:9 Changed 23 months ago by dmethvin

@markrendle, Can you point to the code that was failing? We're trying to determine whether just ignoring the text nodes during traversal would give us the correct results.

comment:10 Changed 23 months ago by markrendle

 https://github.com/angular/angular.js/blob/master/src/ng/compile.js#L313

What happens (in my app, at least) is, the call on line 316 to jqLite (which is jQuery if it's present) passes a <div>, a text node "\n" and another <div>. The return is [element, undefined, element], which then causes an error on line 321, "no property nodeType on undefined".

It's possible that splicing the text node out of the array, either at Angular's end or in the jQuery function, would fix the issue; I haven't tried it though.

comment:11 Changed 23 months ago by dmethvin

  • Milestone changed from None to 1.9.1

Thanks Mark! This is funny, their code is basically faced with the same dilemma we have about text nodes and their workaround is what breaks:

 https://github.com/angular/angular.js/blob/master/src/ng/compile.js#L318

This could easily be rewritten to avoid the traversal method, and is depending on undocumented behavior as it is right now.

During a meeting discussion we talked about changing the behavior of 1.9.1 traversal methods so I'll mark this for action there.

comment:12 Changed 23 months ago by dmethvin

  • Owner changed from markrendle to dmethvin
  • Status changed from open to assigned

I'll touch base with the Angular guys and convince them to rearrange that code slightly, so that they start with an element and append the text node, which is the kosher way to do it.

comment:13 Changed 23 months ago by Richard Gibson

  • Status changed from assigned to closed
  • Resolution set to fixed

Fix #13265 #13332: Allow .parent/.closest with text nodes. Close gh-1146.

Changeset: 5e29ff7e59a0c97bae02b7512b40486df0f44022

comment:14 Changed 23 months ago by dmethvin

  • Milestone changed from 1.9.1 to 1.9.2

comment:15 Changed 23 months ago by Richard Gibson

Fix #13265 #13332: traversing methods with text nodes. Close gh-1145.

Changeset: b734666f4d2e9a92b8ebb99db5b05bd4c82e71f2

comment:16 Changed 19 months ago by dmethvin

  • Milestone changed from 1.9.2 to 1.10/2.0

Bulk update to milestone 1.10/2.0

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