First draft of refactored Component->Configurable.

IPython/config/configurable.py

@@ -0,0 +1,136 b''
+#!/usr/bin/env python
+# encoding: utf-8
+"""
+A base class for objects that are configurable.
+
+Authors:
+
+* Brian Granger
+* Fernando Perez
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2010  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+from copy import deepcopy
+import datetime
+from weakref import WeakValueDictionary
+
+from IPython.utils.importstring import import_item
+from loader import Config
+from IPython.utils.traitlets import HasTraits, Instance
+
+
+#-----------------------------------------------------------------------------
+# Helper classes for Configurables
+#-----------------------------------------------------------------------------
+
+
+class ConfigurableError(Exception):
+    pass
+
+
+#-----------------------------------------------------------------------------
+# Configurable implementation
+#-----------------------------------------------------------------------------
+
+
+class Configurable(HasTraits):
+
+    config = Instance(Config,(),{})
+    created = None
+
+    def __init__(self, config=None):
+        """Create a conigurable given a config config.
+
+        Parameters
+        ----------
+        config : Config
+            If this is empty, default values are used. If config is a 
+            :class:`Config` instance, it will be used to configure the
+            instance.
+        
+        Notes
+        -----
+        Subclasses of Configurable must call the :meth:`__init__` method of
+        :class:`Configurable` *before* doing anything else and using 
+        :func:`super`::
+        
+            class MyConfigurable(Configurable):
+                def __init__(self, config=None):
+                    super(MyConfigurable, self).__init__(config)
+                    # Then any other code you need to finish initialization.
+
+        This ensures that instances will be configured properly.
+        """
+        super(Configurable, self).__init__()
+        if config is not None:
+            # We used to deepcopy, but for now we are trying to just save
+            # by reference.  This *could* have side effects as all components
+            # will share config. In fact, I did find such a side effect in
+            # _config_changed below. If a config attribute value was a mutable type
+            # all instances of a component were getting the same copy, effectively
+            # making that a class attribute.
+            # self.config = deepcopy(config)
+            self.config = config
+        self.created = datetime.datetime.now()
+
+    #-------------------------------------------------------------------------
+    # Static trait notifiations
+    #-------------------------------------------------------------------------
+
+    def _config_changed(self, name, old, new):
+        """Update all the class traits having ``config=True`` as metadata.
+
+        For any class trait with a ``config`` metadata attribute that is
+        ``True``, we update the trait with the value of the corresponding
+        config entry.
+        """
+        # Get all traits with a config metadata entry that is True
+        traits = self.traits(config=True)
+
+        # We auto-load config section for this class as well as any parent
+        # classes that are Configurable subclasses.  This starts with Configurable
+        # and works down the mro loading the config for each section.
+        section_names = [cls.__name__ for cls in \
+            reversed(self.__class__.__mro__) if 
+            issubclass(cls, Configurable) and issubclass(self.__class__, cls)]
+
+        for sname in section_names:
+            # Don't do a blind getattr as that would cause the config to 
+            # dynamically create the section with name self.__class__.__name__.
+            if new._has_section(sname):
+                my_config = new[sname]
+                for k, v in traits.items():
+                    # Don't allow traitlets with config=True to start with
+                    # uppercase.  Otherwise, they are confused with Config
+                    # subsections.  But, developers shouldn't have uppercase
+                    # attributes anyways! (PEP 6)
+                    if k[0].upper()==k[0] and not k.startswith('_'):
+                        raise ConfigurableError('Configurable traitlets with '
+                        'config=True must start with a lowercase so they are '
+                        'not confused with Config subsections: %s.%s' % \
+                        (self.__class__.__name__, k))
+                    try:
+                        # Here we grab the value from the config
+                        # If k has the naming convention of a config
+                        # section, it will be auto created.
+                        config_value = my_config[k]
+                    except KeyError:
+                        pass
+                    else:
+                        # print "Setting %s.%s from %s.%s=%r" % \
+                        #     (self.__class__.__name__,k,sname,k,config_value)
+                        # We have to do a deepcopy here if we don't deepcopy the entire
+                        # config object. If we don't, a mutable config_value will be
+                        # shared by all instances, effectively making it a class attribute.
+                        setattr(self, k, deepcopy(config_value))
+

IPython/config/tests/test_configurable.py

@@ -0,0 +1,95 b''
+#!/usr/bin/env python
+# encoding: utf-8
+"""
+Tests for IPython.config.configurable
+
+Authors:
+
+* Brian Granger
+* Fernando Perez (design help)
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2010  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+from unittest import TestCase
+
+from IPython.config.configurable import Configurable, ConfigurableError
+from IPython.utils.traitlets import (
+    TraitError, Int, Float, Str
+)
+from IPython.config.loader import Config
+
+
+#-----------------------------------------------------------------------------
+# Test cases
+#-----------------------------------------------------------------------------
+
+
+class TestConfigurableConfig(TestCase):
+
+    def test_default(self):
+        c1 = Configurable()
+        c2 = Configurable(config=c1.config)
+        c3 = Configurable(config=c2.config)
+        self.assertEquals(c1.config, c2.config)
+        self.assertEquals(c2.config, c3.config)
+
+    def test_custom(self):
+        config = Config()
+        config.foo = 'foo'
+        config.bar = 'bar'
+        c1 = Configurable(config=config)
+        c2 = Configurable(c1.config)
+        c3 = Configurable(c2.config)
+        self.assertEquals(c1.config, config)
+        self.assertEquals(c2.config, config)
+        self.assertEquals(c3.config, config)
+        # Test that copies are not made
+        self.assert_(c1.config is config)
+        self.assert_(c2.config is config)
+        self.assert_(c3.config is config)
+        self.assert_(c1.config is c2.config)
+        self.assert_(c2.config is c3.config)
+        
+    def test_inheritance(self):
+        class MyConfigurable(Configurable):
+            a = Int(1, config=True)
+            b = Float(1.0, config=True)
+            c = Str('no config')
+        config = Config()
+        config.MyConfigurable.a = 2
+        config.MyConfigurable.b = 2.0
+        c1 = MyConfigurable(config=config)
+        c2 = MyConfigurable(c1.config)
+        self.assertEquals(c1.a, config.MyConfigurable.a)
+        self.assertEquals(c1.b, config.MyConfigurable.b)
+        self.assertEquals(c2.a, config.MyConfigurable.a)
+        self.assertEquals(c2.b, config.MyConfigurable.b)
+
+    def test_parent(self):
+        class Foo(Configurable):
+            a = Int(0, config=True)
+            b = Str('nope', config=True)
+        class Bar(Foo):
+            b = Str('gotit', config=False)
+            c = Float(config=True)
+        config = Config()
+        config.Foo.a = 10
+        config.Foo.b = "wow"
+        config.Bar.b = 'later'
+        config.Bar.c = 100.0
+        f = Foo(config=config)
+        b = Bar(f.config)
+        self.assertEquals(f.a, 10)
+        self.assertEquals(f.b, 'wow')
+        self.assertEquals(b.b, 'gotit')
+        self.assertEquals(b.c, 100.0)

IPython/core/extensions.py

@@ -0,0 +1,124 b''
+# encoding: utf-8
+"""A class for managing IPython extensions.
+
+Authors:
+
+* Brian Granger
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2010  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import os
+import sys
+
+from IPython.config.configurable import Configurable
+from IPython.utils.traitlets import Instance
+
+#-----------------------------------------------------------------------------
+# Main class
+#-----------------------------------------------------------------------------
+
+class ExtensionManager(Configurable):
+
+    shell = Instance('IPython.core.iplib.InteractiveShell')
+
+    def __init__(self, shell, config=None):
+        super(ExtensionManager, self).__init__(config=config)
+        self.shell = shell
+        self.shell.on_trait_change(
+            self._on_ipython_dir_changed, 'ipython_dir'
+        )
+
+    def __del__(self):
+        self.shell.on_trait_change(
+            self._on_ipython_dir_changed, 'ipython_dir', remove=True
+        )
+
+    @property
+    def ipython_extension_dir(self):
+        return os.path.join(self.shell.ipython_dir, u'extensions')
+
+    def _on_ipython_dir_changed(self):
+        if not os.path.isdir(self.ipython_extension_dir):
+            os.makedirs(self.ipython_extension_dir, mode = 0777)
+
+    def load_extension(self, module_str):
+        """Load an IPython extension by its module name.
+
+        An IPython extension is an importable Python module that has
+        a function with the signature::
+
+            def load_ipython_extension(ipython):
+                # Do things with ipython
+
+        This function is called after your extension is imported and the 
+        currently active :class:`InteractiveShell` instance is passed as
+        the only argument.  You can do anything you want with IPython at
+        that point, including defining new magic and aliases, adding new
+        components, etc.
+
+        The :func:`load_ipython_extension` will be called again is you 
+        load or reload the extension again.  It is up to the extension
+        author to add code to manage that.
+
+        You can put your extension modules anywhere you want, as long as
+        they can be imported by Python's standard import mechanism.  However,
+        to make it easy to write extensions, you can also put your extensions
+        in ``os.path.join(self.ipython_dir, 'extensions')``.  This directory
+        is added to ``sys.path`` automatically.
+
+        If :func:`load_ipython_extension` returns anything, this function
+        will return that object.
+        """
+        from IPython.utils.syspathcontext import prepended_to_syspath
+
+        if module_str not in sys.modules:
+            with prepended_to_syspath(self.ipython_extension_dir):
+                __import__(module_str)
+        mod = sys.modules[module_str]
+        return self._call_load_ipython_extension(mod)
+
+    def unload_extension(self, module_str):
+        """Unload an IPython extension by its module name.
+
+        This function looks up the extension's name in ``sys.modules`` and
+        simply calls ``mod.unload_ipython_extension(self)``.
+        """
+        if module_str in sys.modules:
+            mod = sys.modules[module_str]
+            self._call_unload_ipython_extension(mod)
+
+    def reload_extension(self, module_str):
+        """Reload an IPython extension by calling reload.
+
+        If the module has not been loaded before,
+        :meth:`InteractiveShell.load_extension` is called. Otherwise
+        :func:`reload` is called and then the :func:`load_ipython_extension`
+        function of the module, if it exists is called.
+        """
+        from IPython.utils.syspathcontext import prepended_to_syspath
+
+        with prepended_to_syspath(self.ipython_extension_dir):
+            if module_str in sys.modules:
+                mod = sys.modules[module_str]
+                reload(mod)
+                self._call_load_ipython_extension(mod)
+            else:
+                self.load_extension(module_str)
+
+    def _call_load_ipython_extension(self, mod):
+        if hasattr(mod, 'load_ipython_extension'):
+            return mod.load_ipython_extension(self.shell)
+
+    def _call_unload_ipython_extension(self, mod):
+        if hasattr(mod, 'unload_ipython_extension'):
+            return mod.unload_ipython_extension(self.shell)
  No newline at end of file

IPython/core/alias.py

@@ -1,10 +1,11 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
-IPython's alias component
+System command aliases.
 
 Authors:
 
+* Fernando Perez
 * Brian Granger
 """
 
@@ -25,10 +26,10 b' import os'
 import re
 import sys
 
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 from IPython.core.splitinput import split_user_input
 
-from IPython.utils.traitlets import List
+from IPython.utils.traitlets import List, Instance
 from IPython.utils.autoattr import auto_attr
 from IPython.utils.warn import warn, error
 
@@ -99,22 +100,18 b' class InvalidAliasError(AliasError):'
 #-----------------------------------------------------------------------------
 
 
-class AliasManager(Component):
+class AliasManager(Configurable):
 
     default_aliases = List(default_aliases(), config=True)
     user_aliases = List(default_value=[], config=True)
+    shell = Instance('IPython.core.iplib.InteractiveShell')
 
-    def __init__(self, parent, config=None):
-        super(AliasManager, self).__init__(parent, config=config)
+    def __init__(self, shell, config=None):
+        super(AliasManager, self).__init__(config=config)
         self.alias_table = {}
         self.exclude_aliases()
         self.init_aliases()
-
-    @auto_attr
-    def shell(self):
-        return Component.get_instances(
-            root=self.root,
-            klass='IPython.core.iplib.InteractiveShell')[0]
+        self.shell = shell
 
     def __contains__(self, name):
         if name in self.alias_table:

IPython/core/application.py

@@ -6,7 +6,7 b' All top-level applications should use the classes in this module for'
 handling configuration and creating componenets.
 
 The job of an :class:`Application` is to create the master configuration 
-object and then create the components, passing the config to them.
+object and then create the configurable objects, passing the config to them.
 
 Authors:
 
@@ -76,7 +76,7 b' class BaseAppConfigLoader(ArgParseConfigLoader):'
 
 
 class Application(object):
-    """Load a config, construct components and set them running.
+    """Load a config, construct configurables and set them running.
 
     The configuration of an application can be done via three different Config
     objects, which are loaded and ultimately merged into a single one used
@@ -113,7 +113,7 b' class Application(object):'
     file_config = None
     #: Read from the system's command line flags.
     command_line_config = None
-    #: The final config that will be passed to the component.
+    #: The final config that will be passed to the main object.
     master_config = None
     #: A reference to the argv to be used (typically ends up being sys.argv[1:])
     argv = None
@@ -223,10 +223,10 b' class Application(object):'
         """Create defaults that can't be set elsewhere.
 
         For the most part, we try to set default in the class attributes
-        of Components.  But, defaults the top-level Application (which is
-        not a HasTraits or Component) are not set in this way.  Instead
+        of Configurables.  But, defaults the top-level Application (which is
+        not a HasTraits or Configurables) are not set in this way.  Instead
         we set them here.  The Global section is for variables like this that
-        don't belong to a particular component.
+        don't belong to a particular configurable.
         """
         c = Config()
         c.Global.ipython_dir = get_ipython_dir()
@@ -418,8 +418,8 b' class Application(object):'
         pass
 
     def construct(self):
-        """Construct the main components that make up this app."""
-        self.log.debug("Constructing components for application")
+        """Construct the main objects that make up this app."""
+        self.log.debug("Constructing main objects for application")
 
     def post_construct(self):
         """Do actions after construct, but before starting the app."""

IPython/core/builtin_trap.py

@@ -21,10 +21,10 b' Authors:'
 
 import __builtin__
 
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 from IPython.core.quitter import Quitter
 
-from IPython.utils.autoattr import auto_attr
+from IPython.utils.traitlets import Instance
 
 #-----------------------------------------------------------------------------
 # Classes and functions
@@ -35,20 +35,17 b' class __BuiltinUndefined(object): pass'
 BuiltinUndefined = __BuiltinUndefined()
 
 
-class BuiltinTrap(Component):
+class BuiltinTrap(Configurable):
 
-    def __init__(self, parent):
-        super(BuiltinTrap, self).__init__(parent, None, None)
+    shell = Instance('IPython.core.iplib.InteractiveShell')
+
+    def __init__(self, shell):
+        super(BuiltinTrap, self).__init__(None)
         self._orig_builtins = {}
         # We define this to track if a single BuiltinTrap is nested.
         # Only turn off the trap when the outermost call to __exit__ is made.
         self._nested_level = 0
-
-    @auto_attr
-    def shell(self):
-        return Component.get_instances(
-            root=self.root,
-            klass='IPython.core.iplib.InteractiveShell')[0]
+        self.shell = shell
 
     def __enter__(self):
         if self._nested_level == 0:

IPython/core/display_trap.py

@@ -22,34 +22,28 b' Authors:'
 
 import sys
 
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 
-class DisplayTrap(Component):
+class DisplayTrap(Configurable):
     """Object to manage sys.displayhook.
 
     This came from IPython.core.kernel.display_hook, but is simplified
     (no callbacks or formatters) until more of the core is refactored.
     """
 
-    def __init__(self, parent, hook):
-        super(DisplayTrap, self).__init__(parent, None, None)
+    def __init__(self, hook):
+        super(DisplayTrap, self).__init__(None)
         self.hook = hook
         self.old_hook = None
         # We define this to track if a single BuiltinTrap is nested.
         # Only turn off the trap when the outermost call to __exit__ is made.
         self._nested_level = 0
 
-    # @auto_attr
-    # def shell(self):
-    #     return Component.get_instances(
-    #         root=self.root,
-    #         klass='IPython.core.iplib.InteractiveShell')[0]
-
     def __enter__(self):
         if self._nested_level == 0:
             self.set()

IPython/core/ipapi.py

@@ -24,13 +24,7 b' has been made into a component, this module will be sent to deathrow.'
 
 
 def get():
-    """Get the most recently created InteractiveShell instance."""
+    """Get the global InteractiveShell instance."""
     from IPython.core.iplib import InteractiveShell
-    insts = InteractiveShell.get_instances()
-    if len(insts)==0:
-        return None
-    most_recent = insts[0]
-    for inst in insts[1:]:
-        if inst.created > most_recent.created:
-            most_recent = inst
-    return most_recent
+    return InteractiveShell.instance()
+

IPython/core/ipapp.py

@@ -475,8 +475,8 b' class IPythonApp(Application):'
         # But that might be the place for them
         sys.path.insert(0, '')
 
-        # Create an InteractiveShell instance
-        self.shell = InteractiveShell(None, self.master_config)
+        # Create an InteractiveShell instance.
+        self.shell = InteractiveShell.instance(config=self.master_config)
 
     def post_construct(self):
         """Do actions after construct, but before starting the app."""
@@ -543,7 +543,7 b' class IPythonApp(Application):'
     def _load_extensions(self):
         """Load all IPython extensions in Global.extensions.
 
-        This uses the :meth:`InteractiveShell.load_extensions` to load all
+        This uses the :meth:`ExtensionManager.load_extensions` to load all
         the extensions listed in ``self.master_config.Global.extensions``.
         """
         try:
@@ -553,7 +553,7 b' class IPythonApp(Application):'
                 for ext in extensions:
                     try:
                         self.log.info("Loading IPython extension: %s" % ext)                        
-                        self.shell.load_extension(ext)
+                        self.shell.extension_manager.load_extension(ext)
                     except:
                         self.log.warn("Error in loading extension: %s" % ext)
                         self.shell.showtraceback()

IPython/core/iplib.py

@@ -1,12 +1,10 b''
 # -*- coding: utf-8 -*-
-"""
-Main IPython Component
-"""
+"""Main IPython class."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2001 Janko Hauser <[e-mail]>
 #  Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
-#  Copyright (C) 2008-2009  The IPython Development Team
+#  Copyright (C) 2008-2010  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
@@ -38,9 +36,10 b' from IPython.core import shadowns'
 from IPython.core import ultratb
 from IPython.core.alias import AliasManager
 from IPython.core.builtin_trap import BuiltinTrap
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.error import TryNext, UsageError
+from IPython.core.extensions import ExtensionManager
 from IPython.core.fakemodule import FakeModule, init_fakemod_dict
 from IPython.core.logger import Logger
 from IPython.core.magic import Magic
@@ -69,7 +68,7 b' from IPython.utils.syspathcontext import prepended_to_syspath'
 from IPython.utils.terminal import toggle_set_term_title, set_term_title
 from IPython.utils.warn import warn, error, fatal
 from IPython.utils.traitlets import (
-    Int, Str, CBool, CaselessStrEnum, Enum, List, Unicode
+    Int, Str, CBool, CaselessStrEnum, Enum, List, Unicode, Instance
 )
 
 # from IPython.utils import growl
@@ -196,7 +195,7 b' class SeparateStr(Str):'
 #-----------------------------------------------------------------------------
 
 
-class InteractiveShell(Component, Magic):
+class InteractiveShell(Configurable, Magic):
     """An enhanced, interactive shell for Python."""
 
     autocall = Enum((0,1,2), default_value=1, config=True)
@@ -281,14 +280,21 b' class InteractiveShell(Component, Magic):'
     # Subclasses with thread support should override this as needed.
     isthreaded = False
 
-    def __init__(self, parent=None, config=None, ipython_dir=None, usage=None,
+    # Subcomponents of InteractiveShell
+    alias_manager = Instance('IPython.core.alias.AliasManager')
+    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
+    builtin_trap = Instance('IPython.core.builtin_trap.BuiltinTrap')
+    display_trap = Instance('IPython.core.display_trap.DisplayTrap')
+    extension_manager = Instance('IPython.core.extensions.ExtensionManager')
+
+    def __init__(self, config=None, ipython_dir=None, usage=None,
                  user_ns=None, user_global_ns=None,
                  banner1=None, banner2=None, display_banner=None,
                  custom_exceptions=((),None)):
 
         # This is where traits with a config_key argument are updated
         # from the values on config.
-        super(InteractiveShell, self).__init__(parent, config=config)
+        super(InteractiveShell, self).__init__(config=config)
 
         # These are relatively independent and stateless
         self.init_ipython_dir(ipython_dir)
@@ -334,8 +340,20 b' class InteractiveShell(Component, Magic):'
         self.init_reload_doctest()
         self.init_magics()
         self.init_pdb()
+        self.init_extension_manager()
         self.hooks.late_startup_hook()
 
+    @classmethod
+    def instance(cls, *args, **kwargs):
+        """Returns a global InteractiveShell instance."""
+        if not hasattr(cls, "_instance"):
+            cls._instance = cls(*args, **kwargs)
+        return cls._instance
+
+    @classmethod
+    def initialized(cls):
+        return hasattr(cls, "_instance")
+
     def get_ipython(self):
         """Return the currently running IPython instance."""
         return self
@@ -353,12 +371,6 b' class InteractiveShell(Component, Magic):'
     def _ipython_dir_changed(self, name, new):
         if not os.path.isdir(new):
             os.makedirs(new, mode = 0777)
-        if not os.path.isdir(self.ipython_extension_dir):
-            os.makedirs(self.ipython_extension_dir, mode = 0777)
-
-    @property
-    def ipython_extension_dir(self):
-        return os.path.join(self.ipython_dir, 'extensions')
 
     @property
     def usable_screen_length(self):
@@ -523,7 +535,7 b' class InteractiveShell(Component, Magic):'
             pass
 
     def init_displayhook(self):
-        self.display_trap = DisplayTrap(self, self.outputcache)
+        self.display_trap = DisplayTrap(self.outputcache)
 
     def init_reload_doctest(self):
         # Do a proper resetting of doctest, including the necessary displayhook
@@ -1747,6 +1759,13 b' class InteractiveShell(Component, Magic):'
         self.ns_table['alias'] = self.alias_manager.alias_table,
 
     #-------------------------------------------------------------------------
+    # Things related to extensions
+    #-------------------------------------------------------------------------
+
+    def init_extension_manager(self):
+        self.extension_manager = ExtensionManager(self, config=self.config)
+
+    #-------------------------------------------------------------------------
     # Things related to the running of code
     #-------------------------------------------------------------------------
 
@@ -2340,96 +2359,6 b' class InteractiveShell(Component, Magic):'
             return lineout
 
     #-------------------------------------------------------------------------
-    # Working with components
-    #-------------------------------------------------------------------------
-
-    def get_component(self, name=None, klass=None):
-        """Fetch a component by name and klass in my tree."""
-        c = Component.get_instances(root=self, name=name, klass=klass)
-        if len(c) == 0:
-            return None
-        if len(c) == 1:
-            return c[0]
-        else:
-            return c
-
-    #-------------------------------------------------------------------------
-    # IPython extensions
-    #-------------------------------------------------------------------------
-
-    def load_extension(self, module_str):
-        """Load an IPython extension by its module name.
-
-        An IPython extension is an importable Python module that has
-        a function with the signature::
-
-            def load_ipython_extension(ipython):
-                # Do things with ipython
-
-        This function is called after your extension is imported and the 
-        currently active :class:`InteractiveShell` instance is passed as
-        the only argument.  You can do anything you want with IPython at
-        that point, including defining new magic and aliases, adding new
-        components, etc.
-
-        The :func:`load_ipython_extension` will be called again is you 
-        load or reload the extension again.  It is up to the extension
-        author to add code to manage that.
-
-        You can put your extension modules anywhere you want, as long as
-        they can be imported by Python's standard import mechanism.  However,
-        to make it easy to write extensions, you can also put your extensions
-        in ``os.path.join(self.ipython_dir, 'extensions')``.  This directory
-        is added to ``sys.path`` automatically.
-
-        If :func:`load_ipython_extension` returns anything, this function
-        will return that object.
-        """
-        from IPython.utils.syspathcontext import prepended_to_syspath
-
-        if module_str not in sys.modules:
-            with prepended_to_syspath(self.ipython_extension_dir):
-                __import__(module_str)
-        mod = sys.modules[module_str]
-        return self._call_load_ipython_extension(mod)
-
-    def unload_extension(self, module_str):
-        """Unload an IPython extension by its module name.
-
-        This function looks up the extension's name in ``sys.modules`` and
-        simply calls ``mod.unload_ipython_extension(self)``.
-        """
-        if module_str in sys.modules:
-            mod = sys.modules[module_str]
-            self._call_unload_ipython_extension(mod)
-
-    def reload_extension(self, module_str):
-        """Reload an IPython extension by calling reload.
-
-        If the module has not been loaded before,
-        :meth:`InteractiveShell.load_extension` is called. Otherwise
-        :func:`reload` is called and then the :func:`load_ipython_extension`
-        function of the module, if it exists is called.
-        """
-        from IPython.utils.syspathcontext import prepended_to_syspath
-
-        with prepended_to_syspath(self.ipython_extension_dir):
-            if module_str in sys.modules:
-                mod = sys.modules[module_str]
-                reload(mod)
-                self._call_load_ipython_extension(mod)
-            else:
-                self.load_extension(module_str)
-
-    def _call_load_ipython_extension(self, mod):
-        if hasattr(mod, 'load_ipython_extension'):
-            return mod.load_ipython_extension(self)
-
-    def _call_unload_ipython_extension(self, mod):
-        if hasattr(mod, 'unload_ipython_extension'):
-            return mod.unload_ipython_extension(self)
-
-    #-------------------------------------------------------------------------
     # Things related to the prefilter
     #-------------------------------------------------------------------------
 

IPython/core/magic.py

@@ -97,11 +97,11 b' def compress_dhist(dh):'
 
 # XXX - for some odd reason, if Magic is made a new-style class, we get errors
 # on construction of the main InteractiveShell object.  Something odd is going
-# on with super() calls, Component and the MRO... For now leave it as-is, but
+# on with super() calls, Configurable and the MRO... For now leave it as-is, but
 # eventually this needs to be clarified.
 # BG: This is because InteractiveShell inherits from this, but is itself a 
-# Component. This messes up the MRO in some way. The fix is that we need to
-# make Magic a component that InteractiveShell does not subclass.
+# Configurable. This messes up the MRO in some way. The fix is that we need to
+# make Magic a configurable that InteractiveShell does not subclass.
 
 class Magic:
     """Magic functions for InteractiveShell.
@@ -3586,15 +3586,15 b' Defaulting color scheme to \'NoColor\'"""'
 
     def magic_load_ext(self, module_str):
         """Load an IPython extension by its module name."""
-        return self.load_extension(module_str)
+        return self.extension_manager.load_extension(module_str)
 
     def magic_unload_ext(self, module_str):
         """Unload an IPython extension by its module name."""
-        self.unload_extension(module_str)
+        self.extension_manager.unload_extension(module_str)
 
     def magic_reload_ext(self, module_str):
         """Reload an IPython extension by its module name."""
-        self.reload_extension(module_str)
+        self.extension_manager.reload_extension(module_str)
 
     @testdec.skip_doctest
     def magic_install_profiles(self, s):

IPython/core/prefilter.py

@@ -31,11 +31,11 b' import re'
 
 from IPython.core.alias import AliasManager
 from IPython.core.autocall import IPyAutocall
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 from IPython.core.splitinput import split_user_input
 from IPython.core.page import page
 
-from IPython.utils.traitlets import List, Int, Any, Str, CBool, Bool
+from IPython.utils.traitlets import List, Int, Any, Str, CBool, Bool, Instance
 from IPython.utils.io import Term
 from IPython.utils.text import make_quoted_expr
 from IPython.utils.autoattr import auto_attr
@@ -169,7 +169,7 b' class LineInfo(object):'
 #-----------------------------------------------------------------------------
 
 
-class PrefilterManager(Component):
+class PrefilterManager(Configurable):
     """Main prefilter component.
 
     The IPython prefilter is run on all user input before it is run.  The
@@ -210,19 +210,15 b' class PrefilterManager(Component):'
     """
 
     multi_line_specials = CBool(True, config=True)
+    shell = Instance('IPython.core.iplib.InteractiveShell')
 
-    def __init__(self, parent, config=None):
-        super(PrefilterManager, self).__init__(parent, config=config)
+    def __init__(self, shell, config=None):
+        super(PrefilterManager, self).__init__(config=config)
+        self.shell = shell
         self.init_transformers()
         self.init_handlers()
         self.init_checkers()
 
-    @auto_attr
-    def shell(self):
-        return Component.get_instances(
-            root=self.root,
-            klass='IPython.core.iplib.InteractiveShell')[0]
-
     #-------------------------------------------------------------------------
     # API for managing transformers
     #-------------------------------------------------------------------------
@@ -231,7 +227,7 b' class PrefilterManager(Component):'
         """Create the default transformers."""
         self._transformers = []
         for transformer_cls in _default_transformers:
-            transformer_cls(self, config=self.config)
+            transformer_cls(self.shell, self, config=self.config)
 
     def sort_transformers(self):
         """Sort the transformers by priority.
@@ -265,7 +261,7 b' class PrefilterManager(Component):'
         """Create the default checkers."""
         self._checkers = []
         for checker in _default_checkers:
-            checker(self, config=self.config)
+            checker(self.shell, self, config=self.config)
 
     def sort_checkers(self):
         """Sort the checkers by priority.
@@ -300,7 +296,7 b' class PrefilterManager(Component):'
         self._handlers = {}
         self._esc_handlers = {}
         for handler in _default_handlers:
-            handler(self, config=self.config)
+            handler(self.shell, self, config=self.config)
 
     @property
     def handlers(self):
@@ -445,28 +441,22 b' class PrefilterManager(Component):'
 #-----------------------------------------------------------------------------
 
 
-class PrefilterTransformer(Component):
+class PrefilterTransformer(Configurable):
     """Transform a line of user input."""
 
     priority = Int(100, config=True)
-    shell = Any
-    prefilter_manager = Any
+    # Transformers don't currently use shell or prefilter_manager, but as we
+    # move away from checkers and handlers, they will need them.
+    shell = Instance('IPython.core.iplib.InteractiveShell')
+    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
     enabled = Bool(True, config=True)
 
-    def __init__(self, parent, config=None):
-        super(PrefilterTransformer, self).__init__(parent, config=config)
+    def __init__(self, shell, prefilter_manager, config=None):
+        super(PrefilterTransformer, self).__init__(config=config)
+        self.shell = shell
+        self.prefilter_manager = prefilter_manager
         self.prefilter_manager.register_transformer(self)
 
-    @auto_attr
-    def shell(self):
-        return Component.get_instances(
-            root=self.root,
-            klass='IPython.core.iplib.InteractiveShell')[0]
-
-    @auto_attr
-    def prefilter_manager(self):
-        return PrefilterManager.get_instances(root=self.root)[0]
-
     def transform(self, line, continue_prompt):
         """Transform a line, returning the new one."""
         return None
@@ -561,28 +551,20 b' class IPyPromptTransformer(PrefilterTransformer):'
 #-----------------------------------------------------------------------------
 
 
-class PrefilterChecker(Component):
+class PrefilterChecker(Configurable):
     """Inspect an input line and return a handler for that line."""
 
     priority = Int(100, config=True)
-    shell = Any
-    prefilter_manager = Any
+    shell = Instance('IPython.core.iplib.InteractiveShell')
+    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
     enabled = Bool(True, config=True)
 
-    def __init__(self, parent, config=None):
-        super(PrefilterChecker, self).__init__(parent, config=config)
+    def __init__(self, shell, prefilter_manager, config=None):
+        super(PrefilterChecker, self).__init__(config=config)
+        self.shell = shell
+        self.prefilter_manager = prefilter_manager
         self.prefilter_manager.register_checker(self)
 
-    @auto_attr
-    def shell(self):
-        return Component.get_instances(
-            root=self.root,
-            klass='IPython.core.iplib.InteractiveShell')[0]
-
-    @auto_attr
-    def prefilter_manager(self):
-        return PrefilterManager.get_instances(root=self.root)[0]
-
     def check(self, line_info):
         """Inspect line_info and return a handler instance or None."""
         return None
@@ -709,16 +691,12 b' class AliasChecker(PrefilterChecker):'
 
     priority = Int(800, config=True)
 
-    @auto_attr
-    def alias_manager(self):
-        return AliasManager.get_instances(root=self.root)[0]
-
     def check(self, line_info):
         "Check if the initital identifier on the line is an alias."
         # Note: aliases can not contain '.'
         head = line_info.ifun.split('.',1)[0]
-        if line_info.ifun not in self.alias_manager \
-               or head not in self.alias_manager \
+        if line_info.ifun not in self.shell.alias_manager \
+               or head not in self.shell.alias_manager \
                or is_shadowed(head, self.shell):
             return None
 
@@ -766,31 +744,23 b' class AutocallChecker(PrefilterChecker):'
 #-----------------------------------------------------------------------------
 
 
-class PrefilterHandler(Component):
+class PrefilterHandler(Configurable):
 
     handler_name = Str('normal')
     esc_strings = List([])
-    shell = Any
-    prefilter_manager = Any
+    shell = Instance('IPython.core.iplib.InteractiveShell')
+    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
 
-    def __init__(self, parent, config=None):
-        super(PrefilterHandler, self).__init__(parent, config=config)
+    def __init__(self, shell, prefilter_manager, config=None):
+        super(PrefilterHandler, self).__init__(config=config)
+        self.shell = shell
+        self.prefilter_manager = prefilter_manager
         self.prefilter_manager.register_handler(
             self.handler_name,
             self,
             self.esc_strings
         )
 
-    @auto_attr
-    def shell(self):
-        return Component.get_instances(
-            root=self.root,
-            klass='IPython.core.iplib.InteractiveShell')[0]
-
-    @auto_attr
-    def prefilter_manager(self):
-        return PrefilterManager.get_instances(root=self.root)[0]
-
     def handle(self, line_info):
         # print "normal: ", line_info
         """Handle normal input lines. Use as a template for handlers."""
@@ -827,13 +797,9 b' class AliasHandler(PrefilterHandler):'
 
     handler_name = Str('alias')
 
-    @auto_attr
-    def alias_manager(self):
-        return AliasManager.get_instances(root=self.root)[0]
-
     def handle(self, line_info):
         """Handle alias input lines. """
-        transformed = self.alias_manager.expand_aliases(line_info.ifun,line_info.the_rest)
+        transformed = self.shell.alias_manager.expand_aliases(line_info.ifun,line_info.the_rest)
         # pre is needed, because it carries the leading whitespace.  Otherwise
         # aliases won't work in indented sections.
         line_out = '%sget_ipython().system(%s)' % (line_info.pre_whitespace,
@@ -894,7 +860,7 b' class AutoHandler(PrefilterHandler):'
     esc_strings = List([ESC_PAREN, ESC_QUOTE, ESC_QUOTE2])
 
     def handle(self, line_info):
-        """Hande lines which can be auto-executed, quoting if requested."""
+        """Handle lines which can be auto-executed, quoting if requested."""
         line    = line_info.line
         ifun    = line_info.ifun
         the_rest = line_info.the_rest

IPython/extensions/tests/test_pretty.py

@@ -77,7 +77,7 b' a'
 b
 
 ip = get_ipython()
-prd = ip.load_extension('pretty')
+prd = ip.extension_manager.load_extension('pretty')
 prd.for_type(A, a_pretty_printer)
 prd.for_type_by_name(B.__module__, B.__name__, b_pretty_printer)
 

IPython/kernel/clusterdir.py

@@ -26,7 +26,7 b' from twisted.python import log'
 
 from IPython.config.loader import PyFileConfigLoader
 from IPython.core.application import Application, BaseAppConfigLoader
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 from IPython.core.crashhandler import CrashHandler
 from IPython.core import release
 from IPython.utils.path import (
@@ -63,7 +63,7 b' class PIDFileError(Exception):'
 # Class for managing cluster directories
 #-----------------------------------------------------------------------------
 
-class ClusterDir(Component):
+class ClusterDir(Configurable):
     """An object to manage the cluster directory and its resources.
 
     The cluster directory is used by :command:`ipcontroller`, 

IPython/kernel/configobjfactory.py

@@ -18,7 +18,7 b' configuration system.'
 
 import zope.interface as zi
 
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 
 #-----------------------------------------------------------------------------
 # Code
@@ -29,7 +29,7 b' class IConfiguredObjectFactory(zi.Interface):'
     """I am a component that creates a configured object.
 
     This class is useful if you want to configure a class that is not a 
-    subclass of :class:`IPython.core.component.Component`.
+    subclass of :class:`IPython.config.configurable.Configurable`.
     """
 
     def __init__(config):
@@ -39,12 +39,12 b' class IConfiguredObjectFactory(zi.Interface):'
         """Return an instance of the configured object."""
 
 
-class ConfiguredObjectFactory(Component):
+class ConfiguredObjectFactory(Configurable):
 
     zi.implements(IConfiguredObjectFactory)
 
     def __init__(self, config):
-        super(ConfiguredObjectFactory, self).__init__(None, config=config)
+        super(ConfiguredObjectFactory, self).__init__(config=config)
 
     def create(self):
         raise NotImplementedError('create must be implemented in a subclass')
@@ -63,17 +63,17 b' class IAdaptedConfiguredObjectFactory(zi.Interface):'
         """Return an instance of the adapted and configured object."""
 
 
-class AdaptedConfiguredObjectFactory(Component):
+class AdaptedConfiguredObjectFactory(Configurable):
 
     # zi.implements(IAdaptedConfiguredObjectFactory)
 
     def __init__(self, config, adaptee):
         # print
         # print "config pre:", config
-        super(AdaptedConfiguredObjectFactory, self).__init__(None, config=config)
+        super(AdaptedConfiguredObjectFactory, self).__init__(config=config)
         # print
         # print "config post:", config
         self.adaptee = adaptee
 
     def create(self):
-        raise NotImplementedError('create must be implemented in a subclass')
  No newline at end of file
+        raise NotImplementedError('create must be implemented in a subclass')

IPython/kernel/fcutil.py

@@ -191,9 +191,9 b' class FCServiceFactory(AdaptedConfiguredObjectFactory):'
     """This class creates a tub with various services running in it.
 
     The basic idea is that :meth:`create` returns a running :class:`Tub`
-    instance that has a number of Foolscap references registered in it.
-    This class is a subclass of :class:`IPython.core.component.Component`
-    so the IPython configuration and component system are used.
+    instance that has a number of Foolscap references registered in it. This
+    class is a subclass of :class:`IPython.config.configurable.Configurable`
+    so the IPython configuration system is used.
 
     Attributes
     ----------

IPython/kernel/launcher.py

@@ -19,7 +19,7 b' import os'
 import re
 import sys
 
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 from IPython.external import Itpl
 from IPython.utils.traitlets import Str, Int, List, Unicode
 from IPython.utils.path import get_ipython_module_path
@@ -77,7 +77,7 b' class UnknownStatus(LauncherError):'
     pass
 
 
-class BaseLauncher(Component):
+class BaseLauncher(Configurable):
     """An asbtraction for starting, stopping and signaling a process."""
 
     # In all of the launchers, the work_dir is where child processes will be
@@ -89,8 +89,8 b' class BaseLauncher(Component):'
     # the --work-dir option.
     work_dir = Unicode(u'')
 
-    def __init__(self, work_dir, parent=None, name=None, config=None):
-        super(BaseLauncher, self).__init__(parent, name, config)
+    def __init__(self, work_dir, config=None):
+        super(BaseLauncher, self).__init__(config)
         self.work_dir = work_dir
         self.state = 'before' # can be before, running, after
         self.stop_deferreds = []
@@ -265,9 +265,9 b' class LocalProcessLauncher(BaseLauncher):'
     # spawnProcess.
     cmd_and_args = List([])
 
-    def __init__(self, work_dir, parent=None, name=None, config=None):
+    def __init__(self, work_dir, config=None):
         super(LocalProcessLauncher, self).__init__(
-            work_dir, parent, name, config
+            work_dir, config
         )
         self.process_protocol = None
         self.start_deferred = None
@@ -356,9 +356,9 b' class LocalEngineSetLauncher(BaseLauncher):'
         ['--log-to-file','--log-level', '40'], config=True
     )
 
-    def __init__(self, work_dir, parent=None, name=None, config=None):
+    def __init__(self, work_dir, config=None):
         super(LocalEngineSetLauncher, self).__init__(
-            work_dir, parent, name, config
+            work_dir, config
         )
         self.launchers = []
 
@@ -367,7 +367,7 b' class LocalEngineSetLauncher(BaseLauncher):'
         self.cluster_dir = unicode(cluster_dir)
         dlist = []
         for i in range(n):
-            el = LocalEngineLauncher(self.work_dir, self)
+            el = LocalEngineLauncher(self.work_dir, self.config)
             # Copy the engine args over to each engine launcher.
             import copy
             el.engine_args = copy.deepcopy(self.engine_args)
@@ -560,9 +560,9 b' class WindowsHPCLauncher(BaseLauncher):'
     scheduler = Str('', config=True)
     job_cmd = Str(find_job_cmd(), config=True)
 
-    def __init__(self, work_dir, parent=None, name=None, config=None):
+    def __init__(self, work_dir, config=None):
         super(WindowsHPCLauncher, self).__init__(
-            work_dir, parent, name, config
+            work_dir, config
         )
 
     @property
@@ -725,9 +725,9 b' class BatchSystemLauncher(BaseLauncher):'
     # The full path to the instantiated batch script.
     batch_file = Unicode(u'')
 
-    def __init__(self, work_dir, parent=None, name=None, config=None):
+    def __init__(self, work_dir, config=None):
         super(BatchSystemLauncher, self).__init__(
-            work_dir, parent, name, config
+            work_dir, config
         )
         self.batch_file = os.path.join(self.work_dir, self.batch_file_name)
         self.context = {}

IPython/kernel/winhpcjob.py

@@ -24,14 +24,14 b' import uuid'
 
 from xml.etree import ElementTree as ET
 
-from IPython.core.component import Component
+from IPython.config.configurable import Configurable
 from IPython.utils.traitlets import (
     Str, Int, List, Instance,
     Enum, Bool, CStr
 )
 
 #-----------------------------------------------------------------------------
-# Job and Task Component
+# Job and Task classes
 #-----------------------------------------------------------------------------
 
 
@@ -74,7 +74,7 b' def find_username():'
         return '%s\\%s' % (domain, username)
 
 
-class WinHPCJob(Component):
+class WinHPCJob(Configurable):
 
     job_id = Str('')
     job_name = Str('MyJob', config=True)
@@ -165,7 +165,7 b' class WinHPCJob(Component):'
         self.tasks.append(task)
 
 
-class WinHPCTask(Component):
+class WinHPCTask(Configurable):
 
     task_id = Str('')
     task_name = Str('')
@@ -261,8 +261,8 b' class IPControllerTask(WinHPCTask):'
     unit_type = Str("Core", config=False)
     work_directory = CStr('', config=False)
 
-    def __init__(self, parent, name=None, config=None):
-        super(IPControllerTask, self).__init__(parent, name, config)
+    def __init__(self, config=None):
+        super(IPControllerTask, self).__init__(config)
         the_uuid = uuid.uuid1()
         self.std_out_file_path = os.path.join('log','ipcontroller-%s.out' % the_uuid)
         self.std_err_file_path = os.path.join('log','ipcontroller-%s.err' % the_uuid)
@@ -289,8 +289,8 b' class IPEngineTask(WinHPCTask):'
     unit_type = Str("Core", config=False)
     work_directory = CStr('', config=False)
 
-    def __init__(self, parent, name=None, config=None):
-        super(IPEngineTask,self).__init__(parent, name, config)
+    def __init__(self, config=None):
+        super(IPEngineTask,self).__init__(config)
         the_uuid = uuid.uuid1()
         self.std_out_file_path = os.path.join('log','ipengine-%s.out' % the_uuid)
         self.std_err_file_path = os.path.join('log','ipengine-%s.err' % the_uuid)