def add_plugin(self, plugin, override=False, no_fail=False):
"""
Add the plugin ``plugin``.
:param plugin: A subclass of `Plugin` to attempt to add.
:param override: If true, override an already added plugin.
"""
if not callable(plugin):
raise TypeError('plugin must be callable; got %r' % plugin)
# Find the base class or raise SubclassError:
for base in plugin.bases:
if issubclass(base, self.bases):
break
else:
raise errors.PluginSubclassError(
plugin=plugin,
bases=self.bases,
)
# Check override:
prev = self.__plugins_by_key.get(plugin.full_name)
if prev:
if not override:
if no_fail:
return
else:
# Must use override=True to override:
raise errors.PluginOverrideError(
base=base.__name__,
name=plugin.name,
plugin=plugin,
)
self.__plugins.remove(prev)
self.__next[plugin] = prev
else:
if override:
if no_fail:
return
else:
# There was nothing already registered to override:
raise errors.PluginMissingOverrideError(
base=base.__name__,
name=plugin.name,
plugin=plugin,
)
# The plugin is okay, add to sub_d:
self.__plugins.add(plugin)
self.__plugins_by_key[plugin.full_name] = plugin
def add_plugin(self, klass, override=False):
"""
Add the plugin ``klass``.
:param klass: A subclass of `Plugin` to attempt to add.
:param override: If true, override an already added plugin.
"""
if not inspect.isclass(klass):
raise TypeError('plugin must be a class; got %r' % klass)
# Find the base class or raise SubclassError:
found = False
for base in self.bases:
if not issubclass(klass, base):
continue
sub_d = self.__plugins.setdefault(base, {})
found = True
if sub_d.get(klass.__name__) is klass:
continue
# Check override:
if klass.__name__ in sub_d:
if not override:
# Must use override=True to override:
raise errors.PluginOverrideError(
base=base.__name__,
name=klass.__name__,
plugin=klass,
)
else:
if override:
# There was nothing already registered to override:
raise errors.PluginMissingOverrideError(
base=base.__name__,
name=klass.__name__,
plugin=klass,
)
# The plugin is okay, add to sub_d:
sub_d[klass.__name__] = klass
if not found:
raise errors.PluginSubclassError(
plugin=klass,
bases=self.bases,
)