#!/usr/bin/python
# -*- coding: utf-8 -*-

# ---------------------------------------------------------------------
# Copyright (c) 2012 Michael Hull.
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import types

[docs]class PluginDict(object):

    """ Basic component for making features of morphforge 'pluggable'.

    This class simply wraps a dictionary, and exposes some methods to make
    the intention of code clearer.
    """

[docs]    def __init__(self):
        self.dict = {}

[docs]    def register_plugin(self, plugin_name, plugin):
        """ Registers a plugin"""

        # We are expecting classes
        assert plugin_name.__class__ == types.TypeType 
        assert plugin.__class__ == types.TypeType

        assert not plugin_name in self.dict
        self.dict[plugin_name] = plugin

[docs]    def get_plugin(self, plugin_name):
        """ Returns a previously registered plugin"""

        assert plugin_name in self.dict, 'No plugin registered for: %s' % plugin_name
        return self.dict[plugin_name]

[docs]    def __iter__(self):
        return iter(self.dict)
[docs]    def keys(self):
        return self.dict.keys()