563623 - Add API for origin of a network (HTTP) request

Status: RESOLVED INVALID

(Core :: Networking, defect, P5)

Description

[Jan Honza Odvarko [:Honza] (always need-info? me)]

This bug is related to a Firebug issue reported here:
http://code.google.com/p/fbug/issues/detail?id=3053

It would be very useful for web developers to be able (using Firebug) to find the place where (in context of a web page) a network (HTTP) request has been originated.

For example:

- in case of an image request, the developer would be able to see the source <img> element that initiated it.

- in case of a CSS image property, the developer would be able to see URL of the *.css file + line number (e.g.: background: url(image.png)) from where the image has been requested.

etc.

Would it be feasible to provide such APIs for Firebug (and potentially for other tools) ?

Honza

Comment 1

[Boris Zbarsky [:bzbarsky]]

> - in case of an image request, the developer would be able to see the source
< <img> element that initiated it.

Images in particular use a single HTTP request for multiple <img> elements, possibly across different documents.

In any case, in general Necko does not have this information.  All consumers could be changed to pass something useful for the aContext argument of asyncOpen, but for the CSS case you describe above this could have a pretty nontrivial performance cost if nothing else.

All that said, this could be used as a tracking bug for adding such aContext arguments; specific bugs would need to be filed on every place that starts a network load to pass a useful context.

Comment 2

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Link to proper Firebug bug:
http://code.google.com/p/fbug/issues/detail?id=1772

Honza

Comment 3

[Sebastian Zartner [:sebo]]

Attachment: Web Inspector UI for net request origin

FWIW, Web Inspector already has this (while it doesn't seem to be accurate all the time).

Sebastian

Comment 4

[Sebastian Zartner [:sebo]]

> Images in particular use a single HTTP request for multiple <img> elements, 
> possibly across different documents.
Only one element is the initiator of the network request, so it would be correct to just provide one element in this case.

Sebastian

Comment 5

[Sebastian Zartner [:sebo]]

There was question with a good use case for this feature on stackoverflow.[1] That was finding the cause of a 404 page.
IMO this should get a higher priority, because it's an important way to debug pages.

Sebastian

[1] http://stackoverflow.com/questions/19520280/how-do-you-tell-in-firebug-what-url-is-throwing-a-404-not-found-error-in-the-net

Comment 6

[Sebastian Zartner [:sebo]]

(In reply to Jan Honza Odvarko [:Honza] from comment #2)
> Link to proper Firebug bug:
> http://code.google.com/p/fbug/issues/detail?id=1772

For reference, the Firebug issue is now located at https://github.com/firebug/firebug/issues/1911.

FWIW, and this question pops up every now and then. Here's another Stack Overflow question related to this:
http://stackoverflow.com/q/24957437/432681
So I think this feature would help many people to debug their sources.

(In reply to Boris Zbarsky [:bz] from comment #1)
> All that said, this could be used as a tracking bug for adding such aContext
> arguments; specific bugs would need to be filed on every place that starts a
> network load to pass a useful context.

To make progress, I'll start filing those bugs.

Sebastian

Comment 7

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 8

[u597032]

Is this Bug still relevant or can it be closed by now?