def checkPlugin(pluginName, packageName, minimumVersion=None,
featureName=None, featureCheck=None):
"""
Check if the given plug-in is available.
Return a result with an error if it is not, or not new enough.
@param pluginName: name of the plugin to check
@param packageName: name of the package to tell the user to install
if the check fails
@param minimumVersion: minimum version of the plugin, as a tuple.
Optional.
@param featureName: name of a specific feature to check for in the
plugin. Optional. Overrides the minimum version check, if given.
@param featureCheck: function to call on the found feature, which
should return a boolean representing whether the feature is good or
not. Optional, and only makes sense if you specify featureName.
@rtype: L{messages.Result}
"""
result = messages.Result()
version = gstreamer.get_plugin_version(pluginName)
if not version:
m = messages.Error(T_(
N_("This host is missing the '%s' GStreamer plug-in.\n"),
pluginName))
m.add(T_(N_(
"Please install '%s'.\n"), packageName))
documentation.messageAddGStreamerInstall(m)
result.add(m)
elif featureName:
r = Gst.registry_get()
features = r.get_feature_list_by_plugin(pluginName)
byname = dict([(f.get_name(), f) for f in features])
if (featureName not in byname
or (featureCheck and not featureCheck(byname[featureName]))):
m = messages.Error(T_(
N_("Your '%s' GStreamer plug-in is too old.\n"), pluginName),
mid = 'plugin-%s-check' % pluginName)
m.add(T_(N_(
"Please upgrade '%s' to version %s or higher."),
packageName, ".".join([str(x) for x in minimumVersion])))
documentation.messageAddGStreamerInstall(m)
result.add(m)
elif version < minimumVersion:
m = messages.Error(T_(
N_("Version %s of the '%s' GStreamer plug-in is too old.\n"),
".".join([str(x) for x in version]), pluginName),
mid = 'plugin-%s-check' % pluginName)
m.add(T_(N_(
"Please upgrade '%s' to version %s."), packageName,
".".join([str(x) for x in minimumVersion])))
documentation.messageAddGStreamerInstall(m)
result.add(m)
result.succeed(None)
return defer.succeed(result)
