1
# Copyright (C) 2007-2010 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18
"""Support for plugin hooking logic."""
19
from bzrlib import registry
20
from bzrlib.lazy_import import lazy_import
21
lazy_import(globals(), """
25
_format_version_tuple,
28
from bzrlib.help_topics import help_as_plain_text
32
known_hooks = registry.Registry()
33
# known_hooks registry contains
34
# tuple of (module, member name) which is the hook point
35
# module where the specific hooks are defined
36
# callable to get the empty specific Hooks for that attribute
37
known_hooks.register_lazy(('bzrlib.branch', 'Branch.hooks'), 'bzrlib.branch',
39
known_hooks.register_lazy(('bzrlib.bzrdir', 'BzrDir.hooks'), 'bzrlib.bzrdir',
41
known_hooks.register_lazy(('bzrlib.commands', 'Command.hooks'),
42
'bzrlib.commands', 'CommandHooks')
43
known_hooks.register_lazy(('bzrlib.info', 'hooks'),
44
'bzrlib.info', 'InfoHooks')
45
known_hooks.register_lazy(('bzrlib.lock', 'Lock.hooks'), 'bzrlib.lock',
47
known_hooks.register_lazy(('bzrlib.merge', 'Merger.hooks'), 'bzrlib.merge',
49
known_hooks.register_lazy(('bzrlib.msgeditor', 'hooks'), 'bzrlib.msgeditor',
51
known_hooks.register_lazy(('bzrlib.mutabletree', 'MutableTree.hooks'),
52
'bzrlib.mutabletree', 'MutableTreeHooks')
53
known_hooks.register_lazy(('bzrlib.smart.client', '_SmartClient.hooks'),
54
'bzrlib.smart.client', 'SmartClientHooks')
55
known_hooks.register_lazy(('bzrlib.smart.server', 'SmartTCPServer.hooks'),
56
'bzrlib.smart.server', 'SmartServerHooks')
57
known_hooks.register_lazy(('bzrlib.status', 'hooks'),
58
'bzrlib.status', 'StatusHooks')
59
known_hooks.register_lazy(
60
('bzrlib.version_info_formats.format_rio', 'RioVersionInfoBuilder.hooks'),
61
'bzrlib.version_info_formats.format_rio', 'RioVersionInfoBuilderHooks')
62
known_hooks.register_lazy(
63
('bzrlib.merge_directive', 'BaseMergeDirective.hooks'),
64
'bzrlib.merge_directive', 'MergeDirectiveHooks')
67
def known_hooks_key_to_object((module_name, member_name)):
68
"""Convert a known_hooks key to a object.
70
:param key: A tuple (module_name, member_name) as found in the keys of
71
the known_hooks registry.
72
:return: The object this specifies.
74
return registry._LazyObjectGetter(module_name, member_name).get_obj()
77
def known_hooks_key_to_parent_and_attribute((module_name, member_name)):
78
"""Convert a known_hooks key to a object.
80
:param key: A tuple (module_name, member_name) as found in the keys of
81
the known_hooks registry.
82
:return: The object this specifies.
84
member_list = member_name.rsplit('.', 1)
85
if len(member_list) == 2:
86
parent_name, attribute = member_list
89
attribute = member_name
90
parent = known_hooks_key_to_object((module_name, parent_name))
91
return parent, attribute
95
"""A dictionary mapping hook name to a list of callables.
97
e.g. ['FOO'] Is the list of items to be called when the
98
FOO hook is triggered.
103
self._callable_names = {}
105
def create_hook(self, hook):
106
"""Create a hook which can have callbacks registered for it.
108
:param hook: The hook to create. An object meeting the protocol of
109
bzrlib.hooks.HookPoint. It's name is used as the key for future
112
if hook.name in self:
113
raise errors.DuplicateKey(hook.name)
114
self[hook.name] = hook
117
"""Generate the documentation for this Hooks instance.
119
This introspects all the individual hooks and returns their docs as well.
121
hook_names = sorted(self.keys())
123
name = self.__class__.__name__
124
hook_docs.append(name)
125
hook_docs.append("-"*len(name))
127
for hook_name in hook_names:
128
hook = self[hook_name]
130
hook_docs.append(hook.docs())
131
except AttributeError:
134
strings.append(hook_name)
135
strings.append("~" * len(hook_name))
137
strings.append("An old-style hook. For documentation see the __init__ "
138
"method of '%s'\n" % (name,))
139
hook_docs.extend(strings)
140
return "\n".join(hook_docs)
142
def get_hook_name(self, a_callable):
143
"""Get the name for a_callable for UI display.
145
If no name has been registered, the string 'No hook name' is returned.
146
We use a fixed string rather than repr or the callables module because
147
the code names are rarely meaningful for end users and this is not
148
intended for debugging.
150
return self._callable_names.get(a_callable, "No hook name")
152
def install_named_hook(self, hook_name, a_callable, name):
153
"""Install a_callable in to the hook hook_name, and label it name.
155
:param hook_name: A hook name. See the __init__ method of BranchHooks
156
for the complete list of hooks.
157
:param a_callable: The callable to be invoked when the hook triggers.
158
The exact signature will depend on the hook - see the __init__
159
method of BranchHooks for details on each hook.
160
:param name: A name to associate a_callable with, to show users what is
164
hook = self[hook_name]
166
raise errors.UnknownHook(self.__class__.__name__, hook_name)
168
# list hooks, old-style, not yet deprecated but less useful.
169
hook.append(a_callable)
170
except AttributeError:
171
hook.hook(a_callable, name)
173
self.name_hook(a_callable, name)
175
def name_hook(self, a_callable, name):
176
"""Associate name with a_callable to show users what is running."""
177
self._callable_names[a_callable] = name
180
class HookPoint(object):
181
"""A single hook that clients can register to be called back when it fires.
183
:ivar name: The name of the hook.
184
:ivar doc: The docs for using the hook.
185
:ivar introduced: A version tuple specifying what version the hook was
186
introduced in. None indicates an unknown version.
187
:ivar deprecated: A version tuple specifying what version the hook was
188
deprecated or superseded in. None indicates that the hook is not
189
superseded or deprecated. If the hook is superseded then the doc
190
should describe the recommended replacement hook to register for.
193
def __init__(self, name, doc, introduced, deprecated):
194
"""Create a HookPoint.
196
:param name: The name of the hook, for clients to use when registering.
197
:param doc: The docs for the hook.
198
:param introduced: When the hook was introduced (e.g. (0, 15)).
199
:param deprecated: When the hook was deprecated, None for
204
self.introduced = introduced
205
self.deprecated = deprecated
207
self._callback_names = {}
210
"""Generate the documentation for this HookPoint.
212
:return: A string terminated in \n.
215
strings.append(self.name)
216
strings.append('~'*len(self.name))
219
introduced_string = _format_version_tuple(self.introduced)
221
introduced_string = 'unknown'
222
strings.append('Introduced in: %s' % introduced_string)
224
deprecated_string = _format_version_tuple(self.deprecated)
225
strings.append('Deprecated in: %s' % deprecated_string)
227
strings.extend(textwrap.wrap(self.__doc__,
228
break_long_words=False))
230
return '\n'.join(strings)
232
def __eq__(self, other):
233
return (type(other) == type(self) and
234
other.__dict__ == self.__dict__)
236
def hook(self, callback, callback_label):
237
"""Register a callback to be called when this HookPoint fires.
239
:param callback: The callable to use when this HookPoint fires.
240
:param callback_label: A label to show in the UI while this callback is
243
self._callbacks.append(callback)
244
if callback_label is not None:
245
self._callback_names[callback] = callback_label
248
return iter(self._callbacks)
251
return len(self._callbacks)
255
strings.append("<%s(" % type(self).__name__)
256
strings.append(self.name)
257
strings.append("), callbacks=[")
258
for callback in self._callbacks:
259
strings.append(repr(callback))
261
strings.append(self._callback_names[callback])
263
if len(self._callbacks) == 1:
266
return ''.join(strings)
277
A hook of type *xxx* of class *yyy* needs to be registered using::
279
yyy.hooks.install_named_hook("xxx", ...)
281
See :doc:`Using hooks<../user-guide/hooks>` in the User Guide for examples.
283
The class that contains each hook is given before the hooks it supplies. For
284
instance, BranchHooks as the class is the hooks class for
285
`bzrlib.branch.Branch.hooks`.
287
Each description also indicates whether the hook runs on the client (the
288
machine where bzr was invoked) or the server (the machine addressed by
289
the branch URL). These may be, but are not necessarily, the same machine.
291
Plugins (including hooks) are run on the server if all of these is true:
293
* The connection is via a smart server (accessed with a URL starting with
294
"bzr://", "bzr+ssh://" or "bzr+http://", or accessed via a "http://"
295
URL when a smart server is available via HTTP).
297
* The hook is either server specific or part of general infrastructure rather
298
than client specific code (such as commit).
302
def hooks_help_text(topic):
303
segments = [_help_prefix]
304
for hook_key in sorted(known_hooks.keys()):
305
hooks = known_hooks_key_to_object(hook_key)
306
segments.append(hooks.docs())
307
return '\n'.join(segments)
added
removed
bzrlib/hooks.py
