Proposal to add the ability to load raw .py files as plugins

[Alec Thomas]

I believe it's a bit of a barrier for new plugin authors having to create .egg files. Chris proposed on #trac that .py files in the plugins directory be loaded as plugins and this patch implements the feature.

[Alec Thomas]

Better patch coming soon.

[Alec Thomas]

Better loader. Uses the setuptools infrastructure if available.

[Alec Thomas]

This new patch uses setuptools to fake a plugin on the fly. Perhaps there is a better way to create the fake entry point, but I couldn't figure out how.

[Christian Boos]

What's the point to masquerade those "light" plugins as eggs? I was going to suggest to simply add a line of self.log('Loading source file "%s" ... to the initial patch, in order to make clear what was going on.

I fear a little bit that your latest solution might confuse the users (especially someone who's reading the log and hasn't installed the .py files himself), but then, I'm certainly missing the advantages that this approach might have…

[Alec Thomas]

My idea was to make the light plugins as plugin-like as possible, to avoid breakage. However it looks like there is even more mojo required (in the form of creating and registering a pkg_resources distribution finder of .py files), so it's probably not worth it.

Fake eggs have the advantage that (ideally) they would be completely transparent; they could be dependencies for other plugins, etc. It's probably overkill though, so I'll attach the basic loader patch again.

[Alec Thomas]

One other point to note is that this breaks WebAdmin's plugin module. I believe this is due to the distribution finder being unable to locate the module because there is no registered finder for .py files.

[Alec Thomas]

This patches WebAdmin to work with the .py plugins:

webadmin/plugin.py

@@ -204 +204 @@
         path = module.__file__
         if path.endswith('.pyc') or path.endswith('.pyo'):
             path = path[:-1]
+        file = path
         if os.path.basename(path) == '__init__.py':
             path = os.path.dirname(path)
         path = _find_base_path(path, module.__name__)
@@ -214 +215 @@
         else:
             for dist in pkg_resources.find_distributions(path, only=True):
                 return dist
+            plugins_dir = os.path.realpath(os.path.join(self.env.path,
+                                                        'plugins'))
+            if path == plugins_dir and file.endswith('.py'):
+                module_name = os.path.basename(file[:-3])
+                return pkg_resources.Distribution(project_name=module_name,
+                                                  version='0.1',
+                                                  location=path)
 
+
     def _get_pkginfo(self, dist):
         attrs = ('author', 'author-email', 'license', 'home-page', 'summary',
                  'description')

[Alec Thomas]

New version of old patch with logging as requested

[Christopher Lenz]

Lovely :-)

[Alec Thomas]

Cleaner version using imp.load_source and no longer fondling sys.path

[Christopher Lenz]

Slightly modified patch applied in [3128]. WebAdmin update to follow…

[Christopher Lenz]

WebAdmin updated in [3129].