1
# Copyright (C) 2007, 2008 Canonical Ltd
3
# This program is free software; you can redistribute it and/or modify
4
# it under the terms of the GNU General Public License as published by
5
# the Free Software Foundation; either version 2 of the License, or
6
# (at your option) any later version.
8
# This program is distributed in the hope that it will be useful,
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11
# GNU General Public License for more details.
13
# You should have received a copy of the GNU General Public License
14
# along with this program; if not, write to the Free Software
15
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
"""Support for plugin hooking logic."""
19
from bzrlib.lazy_import import lazy_import
20
from bzrlib import registry
21
from bzrlib.symbol_versioning import deprecated_method, one_five
22
lazy_import(globals(), """
26
_format_version_tuple,
29
from bzrlib.help_topics import help_as_plain_text
33
known_hooks = registry.Registry()
34
known_hooks.register_lazy(('bzrlib.branch', 'Branch.hooks'), 'bzrlib.branch',
36
known_hooks.register_lazy(('bzrlib.bzrdir', 'BzrDir.hooks'), 'bzrlib.bzrdir',
38
known_hooks.register_lazy(('bzrlib.commands', 'Command.hooks'),
39
'bzrlib.commands', 'CommandHooks')
40
known_hooks.register_lazy(('bzrlib.lock', 'Lock.hooks'), 'bzrlib.lock',
42
known_hooks.register_lazy(('bzrlib.mutabletree', 'MutableTree.hooks'),
43
'bzrlib.mutabletree', 'MutableTreeHooks')
44
known_hooks.register_lazy(('bzrlib.smart.client', '_SmartClient.hooks'),
45
'bzrlib.smart.client', 'SmartClientHooks')
46
known_hooks.register_lazy(('bzrlib.smart.server', 'SmartTCPServer.hooks'),
47
'bzrlib.smart.server', 'SmartServerHooks')
50
def known_hooks_key_to_object((module_name, member_name)):
51
"""Convert a known_hooks key to a object.
53
:param key: A tuple (module_name, member_name) as found in the keys of
54
the known_hooks registry.
55
:return: The object this specifies.
57
return registry._LazyObjectGetter(module_name, member_name).get_obj()
60
def known_hooks_key_to_parent_and_attribute((module_name, member_name)):
61
"""Convert a known_hooks key to a object.
63
:param key: A tuple (module_name, member_name) as found in the keys of
64
the known_hooks registry.
65
:return: The object this specifies.
67
member_list = member_name.rsplit('.', 1)
68
if len(member_list) == 2:
69
parent_name, attribute = member_list
72
attribute = member_name
73
parent = known_hooks_key_to_object((module_name, parent_name))
74
return parent, attribute
78
"""A dictionary mapping hook name to a list of callables.
80
e.g. ['FOO'] Is the list of items to be called when the
81
FOO hook is triggered.
86
self._callable_names = {}
88
def create_hook(self, hook):
89
"""Create a hook which can have callbacks registered for it.
91
:param hook: The hook to create. An object meeting the protocol of
92
bzrlib.hooks.HookPoint. It's name is used as the key for future
96
raise errors.DuplicateKey(hook.name)
97
self[hook.name] = hook
100
"""Generate the documentation for this Hooks instance.
102
This introspects all the individual hooks and returns their docs as well.
104
hook_names = sorted(self.keys())
106
name = self.__class__.__name__
107
hook_docs.append(name)
108
hook_docs.append("-"*len(name))
110
for hook_name in hook_names:
111
hook = self[hook_name]
113
hook_docs.append(hook.docs())
114
except AttributeError:
117
strings.append(hook_name)
118
strings.append("~" * len(hook_name))
120
strings.append("An old-style hook. For documentation see the __init__ "
121
"method of '%s'\n" % (name,))
122
hook_docs.extend(strings)
123
return "\n".join(hook_docs)
125
def get_hook_name(self, a_callable):
126
"""Get the name for a_callable for UI display.
128
If no name has been registered, the string 'No hook name' is returned.
129
We use a fixed string rather than repr or the callables module because
130
the code names are rarely meaningful for end users and this is not
131
intended for debugging.
133
return self._callable_names.get(a_callable, "No hook name")
135
@deprecated_method(one_five)
136
def install_hook(self, hook_name, a_callable):
137
"""Install a_callable in to the hook hook_name.
139
:param hook_name: A hook name. See the __init__ method of BranchHooks
140
for the complete list of hooks.
141
:param a_callable: The callable to be invoked when the hook triggers.
142
The exact signature will depend on the hook - see the __init__
143
method of BranchHooks for details on each hook.
145
self.install_named_hook(hook_name, a_callable, None)
147
def install_named_hook(self, hook_name, a_callable, name):
148
"""Install a_callable in to the hook hook_name, and label it name.
150
:param hook_name: A hook name. See the __init__ method of BranchHooks
151
for the complete list of hooks.
152
:param a_callable: The callable to be invoked when the hook triggers.
153
The exact signature will depend on the hook - see the __init__
154
method of BranchHooks for details on each hook.
155
:param name: A name to associate a_callable with, to show users what is
159
hook = self[hook_name]
161
raise errors.UnknownHook(self.__class__.__name__, hook_name)
163
# list hooks, old-style, not yet deprecated but less useful.
164
hook.append(a_callable)
165
except AttributeError:
166
hook.hook(a_callable, name)
168
self.name_hook(a_callable, name)
170
def name_hook(self, a_callable, name):
171
"""Associate name with a_callable to show users what is running."""
172
self._callable_names[a_callable] = name
175
class HookPoint(object):
176
"""A single hook that clients can register to be called back when it fires.
178
:ivar name: The name of the hook.
179
:ivar introduced: A version tuple specifying what version the hook was
180
introduced in. None indicates an unknown version.
181
:ivar deprecated: A version tuple specifying what version the hook was
182
deprecated or superceded in. None indicates that the hook is not
183
superceded or deprecated. If the hook is superceded then the doc
184
should describe the recommended replacement hook to register for.
185
:ivar doc: The docs for using the hook.
188
def __init__(self, name, doc, introduced, deprecated):
189
"""Create a HookPoint.
191
:param name: The name of the hook, for clients to use when registering.
192
:param doc: The docs for the hook.
193
:param introduced: When the hook was introduced (e.g. (0, 15)).
194
:param deprecated: When the hook was deprecated, None for
199
self.introduced = introduced
200
self.deprecated = deprecated
202
self._callback_names = {}
205
"""Generate the documentation for this HookPoint.
207
:return: A string terminated in \n.
210
strings.append(self.name)
211
strings.append('~'*len(self.name))
214
introduced_string = _format_version_tuple(self.introduced)
216
introduced_string = 'unknown'
217
strings.append('Introduced in: %s' % introduced_string)
219
deprecated_string = _format_version_tuple(self.deprecated)
221
deprecated_string = 'Not deprecated'
222
strings.append('Deprecated in: %s' % deprecated_string)
224
strings.extend(textwrap.wrap(self.__doc__))
226
return '\n'.join(strings)
228
def __eq__(self, other):
229
return (type(other) == type(self) and
230
other.__dict__ == self.__dict__)
232
def hook(self, callback, callback_label):
233
"""Register a callback to be called when this HookPoint fires.
235
:param callback: The callable to use when this HookPoint fires.
236
:param callback_label: A label to show in the UI while this callback is
239
self._callbacks.append(callback)
240
if callback_label is not None:
241
self._callback_names[callback] = callback_label
244
return iter(self._callbacks)
247
return len(self._callbacks)
251
strings.append("<%s(" % type(self).__name__)
252
strings.append(self.name)
253
strings.append("), callbacks=[")
254
for callback in self._callbacks:
255
strings.append(repr(callback))
257
strings.append(self._callback_names[callback])
259
if len(self._callbacks) == 1:
262
return ''.join(strings)
273
A hook of type *xxx* of class *yyy* needs to be registered using::
275
yyy.hooks.install_named_hook("xxx", ...)
277
See `Using hooks`_ in the User Guide for examples.
279
.. _Using hooks: ../user-guide/index.html#using-hooks
281
The class that contains each hook is given before the hooks it supplies. For
282
instance, BranchHooks as the class is the hooks class for
283
`bzrlib.branch.Branch.hooks`.
285
Each description also indicates whether the hook runs on the client (the
286
machine where bzr was invoked) or the server (the machine addressed by
287
the branch URL). These may be, but are not necessarily, the same machine.
289
Plugins (including hooks) are run on the server if all of these is true:
291
* The connection is via a smart server (accessed with a URL starting with
292
"bzr://", "bzr+ssh://" or "bzr+http://", or accessed via a "http://"
293
URL when a smart server is available via HTTP).
295
* The hook is either server specific or part of general infrastructure rather
296
than client specific code (such as commit).
300
def hooks_help_text(topic):
301
segments = [_help_prefix]
302
for hook_key in sorted(known_hooks.keys()):
303
hooks = known_hooks_key_to_object(hook_key)
304
segments.append(hooks.docs())
305
return '\n'.join(segments)
added
removed
bzrlib/hooks.py
