plugin – Plugin loader

The plugin module implements a sophisticated, featureful plugin loader with interface-based discovery.

bravo.plugin.add_plugin_edges(d)[source]

Mirror edges to all plugins in a dictionary.

bravo.plugin.expand_names(plugins, names)[source]

Given a list of names, expand wildcards and discard disabled names.

Used to implement * and - options in plugin lists.

Parameters:
  • plugins (dict) – plugins to use for expansion
  • names (list) – names to examine
Returns:

a list of filtered plugin names
bravo.plugin.get_plugins(interface, package)[source]

Lazily find objects in a package which implement a given interface.

This is a rewrite of Twisted’s twisted.plugin.getPlugins which searches for implementations of interfaces rather than providers.

Parameters:
  • interface (interface) – the interface to match against
  • package (str) – the name of the package to search
bravo.plugin.retrieve_named_plugins(interface, names, **kwargs)[source]

Look up a list of plugins by name.

Plugins are returned in the same order as their names.

Parameters:
  • interface (interface) – the interface to use
  • names (list) – plugins to find
  • parameters (dict) – parameters to pass into the plugins
Returns:

a list of plugins
Raises:

PluginException – no plugins could be found for the given interface
bravo.plugin.retrieve_plugins(interface, **kwargs)[source]

Look up all plugins for a certain interface.

If the plugin cache is enabled, this function will not attempt to reload plugins from disk or discover new plugins.

Parameters:
  • interface (interface) – the interface to use
  • parameters (dict) – parameters to pass into the plugins
Returns:

a dict of plugins, keyed by name
Raises:

PluginException – no plugins could be found for the given interface
bravo.plugin.retrieve_sorted_plugins(interface, names, **kwargs)[source]

Look up a list of plugins, sorted by interdependencies.

Parameters:parameters (dict) – parameters to pass into the plugins
bravo.plugin.sort_plugins(plugins)[source]

Make a sorted list of plugins by dependency.

If the list cannot be arranged into a DAG, an error will be raised. This usually means that a cyclic dependency was found.

Raises:PluginException – cyclic dependency detected
bravo.plugin.verify_plugin(interface, plugin)[source]

Plugin interface verification.

This function will call verifyObject() and validateInvariants() on the plugins passed to it.

The primary purpose of this wrapper is to do logging, but it also permits code to be slightly cleaner, easier to test, and callable from other modules.