Notice: E4X is deprecated in SpiderMonkey

[Dave Mandelin]

The SpiderMonkey implementation of E4X is deprecated and will be removed.

The rationale: E4X has a standard, but is not part of the de facto open web: for a long time, it's implemented by only one browser, Firefox, and is not used for open web content. We are trying to advance SpiderMonkey and Firefox rapidly under intense competition, and keeping E4X slows down our development and increases the security attack surface.

This is the plan:

1. Pref off E4X by default for _content_ in Firefox 16, which is the current nightly cycle. It can be turned back on by setting

javascript.options.xml.content=true

but only temporarily, because we will be removing support entirely in the future (see below).

2. Pref off E4X by default for _chrome_ in Firefox 17. This will break some current add-on implementations. Firefox 17 will be released on about Nov 19 according to the standard schedule, so there is lots of time to port add-ons. E4X for chrome can be turned back on for testing purposes by setting

javascript.options.xml.chrome=true

3. Remove the E4X implementation from SpiderMonkey in Firefox 18.

For embedding usages of E4X, I recommend porting to something newer, but if you can't, you can always stick with a downrev SpiderMonkey. E4X will be in the Firefox 17 version, which is also planned as an ESR. Note that because E4X will not be enabled by default, we will not be fixing bugs in E4X itself.

Dave

[decem...@gmail.com]

I post in bugzilla, <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=814633">Firefox 17.0 breaks some Greasemonkey script </a>

i see onw , that it's finally around the EX4 things ...

I hope you find a way to keep EX4 in use by options(for future update more for than Fir 18) if it is possible for my poor old greasemonkey script which worked fine since 2006 and store many useful informations (and for now without support by its author....)

[Nicholas Nethercote]

On Sat, Jun 23, 2012 at 7:53 AM, Dave Mandelin <dman...@mozilla.com> wrote:
> The SpiderMonkey implementation of E4X is deprecated and will be removed.
>

> This is the plan:
>
> 1. Pref off E4X by default for _content_ in Firefox 16, which is the current nightly cycle.
>

> 2. Pref off E4X by default for _chrome_ in Firefox 17.
>

> 3. Remove the E4X implementation from SpiderMonkey in Firefox 18.

Things have happened more slowly than this announced schedule.
However, I am currently working on removing E4X support with the
intention that the E4X implementation will be removed in Firefox 21,
which is due for release on 2013-05-14.

The patches are basically done and are in the reviewing and testing
stages now. If things go smoothly, the patches may land by the end of
this week. See https://bugzilla.mozilla.org/show_bug.cgi?id=833208
and https://bugzilla.mozilla.org/show_bug.cgi?id=788293 for more
details.

Nick

[Nicholas Nethercote]

On Tue, Jan 29, 2013 at 8:04 PM, Nicholas Nethercote
<n.neth...@gmail.com> wrote:
>> The SpiderMonkey implementation of E4X is deprecated and will be removed.
>>

>> 3. Remove the E4X implementation from SpiderMonkey in Firefox 18.
>

> Things have happened more slowly than this announced schedule.
> However, I am currently working on removing E4X support with the
> intention that the E4X implementation will be removed in Firefox 21,
> which is due for release on 2013-05-14.
>
> The patches are basically done and are in the reviewing and testing
> stages now. If things go smoothly, the patches may land by the end of
> this week. See https://bugzilla.mozilla.org/show_bug.cgi?id=833208
> and https://bugzilla.mozilla.org/show_bug.cgi?id=788293 for more
> details.

E4X support has now been removed from mozilla-central, and thus Firefox Nightly.

I closed all the relevant E4X-related bugs I could find in Bugzilla.
I did this by searching for bugs with "e4x" in the title and then
ignoring the ones (a) relating to Rhino, and (b) relating to
follow-ups caused by the removal.

Nick