Files
edx-platform/openedx/core/lib/api/plugins.py
2015-06-02 15:05:16 -04:00

46 lines
1.5 KiB
Python

"""
Adds support for first class features that can be added to the edX platform.
"""
from stevedore.extension import ExtensionManager
class PluginError(Exception):
"""
Base Exception for when an error was found regarding features.
"""
pass
class PluginManager(object):
"""
Base class that manages plugins to the edX platform.
"""
@classmethod
def get_available_plugins(cls):
"""
Returns a dict of all the plugins that have been made available through the platform.
"""
# Note: we're creating the extension manager lazily to ensure that the Python path
# has been correctly set up. Trying to create this statically will fail, unfortunately.
if not hasattr(cls, "_plugins"):
plugins = {}
extension_manager = ExtensionManager(namespace=cls.NAMESPACE) # pylint: disable=no-member
for plugin_name in extension_manager.names():
plugins[plugin_name] = extension_manager[plugin_name].plugin
cls._plugins = plugins
return cls._plugins
@classmethod
def get_plugin(cls, name):
"""
Returns the plugin with the given name.
"""
plugins = cls.get_available_plugins()
if name not in plugins:
raise PluginError("No such plugin {name} for entry point {namespace}".format(
name=name,
namespace=cls.NAMESPACE # pylint: disable=no-member
))
return plugins[name]