Re: PyGObject (3.4.0) - importing overrides modules from different directories

[Simon Feltman <s feltman gmail com>]

Hi Lukas,

You should already be able to use overrides in different paths
searchable by python (anything that shows up in sys.path). The trick
is you need to use pkgutil within each of the __init__.py files within
your custom gi/overrides folders. There are more details which may be
a helpful in this bug report:
https://bugzilla.gnome.org/show_bug.cgi?id=680913

-Simon

On Fri, Oct 26, 2012 at 4:23 AM, Lukas Vacek <lucas vacek gmail com> wrote:
> I see the last mail didn't catch much attention. Anyway, I have come
> up with two possible solutions to the problem.
>
> 1) Use imp instead of __import__
> Just look for a file "gi/overrides/Module_name.py" in sys.path and
> don't worry about __init__.py (overrides module can't use __init__.py
> anyway as they clash with pygobject's overrides' init which is the
> root cause of the whole problem), then load it with imp. It feels a
> bit untidy but works fine. This is the attached
> pygobject-3.4.0-overrides-load-py-files-instead-of-modules.patch.
> Indeed this should look for other supported suffixes than .py as well.
>
> 2) Ask overrides module developers to symlink __init__.py
> This solution feels cleaner and requires no changes to existing
> pygobject code. The solution is to link __init__.py from overrides
> modules to system pygobject overrides directory in case overrides
> module is installed outside of pygobject tree. With autotools, this
> can be done easily by using install-exec-hook -
> gst-python-symlink-__init__.py-to-system-gi-overrides-on-install.patch
> demonstrates this idea on gst-python.
>
> Cheers,
> Lukas Vacek
>
> On Mon, Oct 22, 2012 at 1:35 PM, Lukas Vacek <lucas vacek gmail com> wrote:
>> Hi All,
>>
>> I have found out it's not possible to load installed GI overrides from
>> a different directory than where PyGObject itself is installed
>> (/usr/lib/python2.7/dist-packages/ in my case).
>>
>> Ideally gi overrides modules could be installed to user site-packages
>> directory and still would be loaded by system installation of
>> PyGObject.
>>
>> The problem is that the overrides module can't install __init__.py
>> file because it would conflict with __init__.py already installed by
>> system PyGObject. (Or even if the file was not installed in the same
>> location but the installed overrides module (with own __init__.py)
>> would appear before system PyGObject in sys.path it would be loaded
>> instead of PyGObject as gi module and break things. )
>>
>> However, __init__.py must be present in the gi overrides module
>> directory in order to be recognized by __import__ call made by
>> PyGObject when loading overrides module (module.py around line 244).
>>
>> This makes it complicated to use gi overrides module from a different
>> directory. The workaround is to load _uninstalled_ gi overrides
>> modules with PYTHONPATH which explicitly mentions PyGObject path
>> before the path to overrides modules. For example, this is how I run
>> pitivi: PYTHONPATH=/usr/lib/python2.7/dist-packages/:~/dev/gst-python/
>> python bin/pitivi
>>
>> Pitivi bugs https://bugzilla.gnome.org/show_bug.cgi?id=686341 and
>> https://bugzilla.gnome.org/show_bug.cgi?id=686342 seem to be related
>> to/caused by this.
>>
>> To solve this pygobject might look for a ".py" file instead of a module.
>>
>> Thanks!
>> Lukas Vacek
>
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