[Sugar-devel] web-activity: env.getEnvironment dependency with Python code

[Daniel Narvaez]

It might be a good idea to send an email to the webkitgtk mailing list by
the way.

I wonder if it would make sense to add a window-object-cleared signal to
WebkKitView (webkitgtk1 has it). They provide a way to run javascript code
from the view and it seems being able to run it before any other js code
has been executed would be a very common use case, one you wouldn't want
people to write an extension for...

On Wednesday, 27 November 2013, Daniel Narvaez wrote:

> This makes me wonder if the current approach is actually racy by the
> way... I'm not sure the window object is guaranteed to be ready even on the
> load_finished event. Network and javascript context might be completely
> independent from this point of view (they are in separate processes after
> all).
>
> I feel the best approach here is the webkit extension really, even if it
> requires a little bit of C code.
>
> On Wednesday, 27 November 2013, Daniel Narvaez wrote:
>
>> Hi,
>>
>> did you try to implement it and see if it works? I probably tried this
>> when I first implemented getEnvironment but I might have done it wrong or
>> something. My worry is that the javascript context might not be ready yet
>> at that time, so either the python js code would fail or affect the old
>> view.
>>
>> By the way, if you are determined to solve this and the loaded_started
>> approach doesn't work, I know it would be possible to make it work using
>> this
>>
>> http://webkitgtk.org/reference/webkit2gtk/unstable/WebKitScriptWorld.html
>>
>> It runs in the web process, so it tells you exactly when a new window
>> object is created. Though using that API requires an extension written in C
>> :/ If despite that you are interested in working on that I can give you
>> some more pointers.
>>
>> On Wednesday, 27 November 2013, Rogelio Mita wrote:
>>
>>> I noticed existence of a WebKitWebView event which is emitted before
>>> what any resource be loaded, called webkit_loaded_started<http://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#WEBKIT-LOAD-STARTED:CAPS>
>>>
>>>> WEBKIT_LOAD_STARTED: A new load request has been made. No data has been
>>>> received yet, empty structures have been allocated to perform the load; the
>>>> load may still fail due to transport issues such as not being able to
>>>> resolve a name, or connect to a port.
>>>
>>> I did a concept proof on sugar-toolkit-gtk3 to show this behaviour and
>>> the result was:
>>>
>>> [image: Imágenes integradas 1]
>>>
>>> I think that this behaviour can solve the issue with env.getEnvironment
>>> and your hard dependency with sugar var provided by python code.
>>>
>>> This log also show how load_event_finished is executed between
>>> successive requests, then there is no doubt about the current problem
>>> existence.
>>>
>>> You think this may be a solution?, change the script so that it is now
>>> run in this event (load_event_started) and rewrite getEnvironment
>>> disregarding the possibility that there is no environment variable provided
>>> by the Python code, in others words ever when activity is in sugar mode,
>>> window.sugar.environment will be present
>>>
>>>
>>> --
>>> Roger
>>>
>>> Activity Central <http://activitycentral.com/>
>>>
>>
>>
>> --
>> Daniel Narvaez
>>
>>
>
> --
> Daniel Narvaez
>
>

-- 
Daniel Narvaez
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