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# Copyright (C) 2007, 2008 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""Support for plugin hooking logic."""
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from bzrlib import registry
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from bzrlib.lazy_import import lazy_import
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from bzrlib.symbol_versioning import deprecated_method
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lazy_import(globals(), """
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_format_version_tuple,
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from bzrlib.help_topics import help_as_plain_text
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known_hooks = registry.Registry()
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# known_hooks registry contains
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# tuple of (module, member name) which is the hook point
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# module where the specific hooks are defined
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# callable to get the empty specific Hooks for that attribute
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known_hooks.register_lazy(('bzrlib.branch', 'Branch.hooks'), 'bzrlib.branch',
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known_hooks.register_lazy(('bzrlib.bzrdir', 'BzrDir.hooks'), 'bzrlib.bzrdir',
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known_hooks.register_lazy(('bzrlib.commands', 'Command.hooks'),
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'bzrlib.commands', 'CommandHooks')
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known_hooks.register_lazy(('bzrlib.lock', 'Lock.hooks'), 'bzrlib.lock',
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known_hooks.register_lazy(('bzrlib.msgeditor', 'hooks'), 'bzrlib.msgeditor',
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known_hooks.register_lazy(('bzrlib.mutabletree', 'MutableTree.hooks'),
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'bzrlib.mutabletree', 'MutableTreeHooks')
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known_hooks.register_lazy(('bzrlib.smart.client', '_SmartClient.hooks'),
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'bzrlib.smart.client', 'SmartClientHooks')
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known_hooks.register_lazy(('bzrlib.smart.server', 'SmartTCPServer.hooks'),
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'bzrlib.smart.server', 'SmartServerHooks')
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known_hooks.register_lazy(
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('bzrlib.version_info_formats.format_rio', 'RioVersionInfoBuilder.hooks'),
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'bzrlib.version_info_formats.format_rio', 'RioVersionInfoBuilderHooks')
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def known_hooks_key_to_object((module_name, member_name)):
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"""Convert a known_hooks key to a object.
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:param key: A tuple (module_name, member_name) as found in the keys of
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the known_hooks registry.
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:return: The object this specifies.
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return registry._LazyObjectGetter(module_name, member_name).get_obj()
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def known_hooks_key_to_parent_and_attribute((module_name, member_name)):
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"""Convert a known_hooks key to a object.
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:param key: A tuple (module_name, member_name) as found in the keys of
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the known_hooks registry.
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:return: The object this specifies.
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member_list = member_name.rsplit('.', 1)
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if len(member_list) == 2:
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parent_name, attribute = member_list
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attribute = member_name
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parent = known_hooks_key_to_object((module_name, parent_name))
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return parent, attribute
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"""A dictionary mapping hook name to a list of callables.
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e.g. ['FOO'] Is the list of items to be called when the
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FOO hook is triggered.
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self._callable_names = {}
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def create_hook(self, hook):
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"""Create a hook which can have callbacks registered for it.
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:param hook: The hook to create. An object meeting the protocol of
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bzrlib.hooks.HookPoint. It's name is used as the key for future
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if hook.name in self:
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raise errors.DuplicateKey(hook.name)
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self[hook.name] = hook
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"""Generate the documentation for this Hooks instance.
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This introspects all the individual hooks and returns their docs as well.
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hook_names = sorted(self.keys())
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name = self.__class__.__name__
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hook_docs.append(name)
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hook_docs.append("-"*len(name))
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for hook_name in hook_names:
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hook = self[hook_name]
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hook_docs.append(hook.docs())
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except AttributeError:
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strings.append(hook_name)
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strings.append("~" * len(hook_name))
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strings.append("An old-style hook. For documentation see the __init__ "
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"method of '%s'\n" % (name,))
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hook_docs.extend(strings)
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return "\n".join(hook_docs)
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def get_hook_name(self, a_callable):
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"""Get the name for a_callable for UI display.
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If no name has been registered, the string 'No hook name' is returned.
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We use a fixed string rather than repr or the callables module because
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the code names are rarely meaningful for end users and this is not
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intended for debugging.
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return self._callable_names.get(a_callable, "No hook name")
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def install_named_hook(self, hook_name, a_callable, name):
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"""Install a_callable in to the hook hook_name, and label it name.
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:param hook_name: A hook name. See the __init__ method of BranchHooks
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for the complete list of hooks.
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:param a_callable: The callable to be invoked when the hook triggers.
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The exact signature will depend on the hook - see the __init__
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method of BranchHooks for details on each hook.
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:param name: A name to associate a_callable with, to show users what is
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hook = self[hook_name]
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raise errors.UnknownHook(self.__class__.__name__, hook_name)
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# list hooks, old-style, not yet deprecated but less useful.
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hook.append(a_callable)
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except AttributeError:
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hook.hook(a_callable, name)
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self.name_hook(a_callable, name)
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def name_hook(self, a_callable, name):
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"""Associate name with a_callable to show users what is running."""
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self._callable_names[a_callable] = name
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class HookPoint(object):
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"""A single hook that clients can register to be called back when it fires.
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:ivar name: The name of the hook.
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:ivar introduced: A version tuple specifying what version the hook was
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introduced in. None indicates an unknown version.
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:ivar deprecated: A version tuple specifying what version the hook was
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deprecated or superceded in. None indicates that the hook is not
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superceded or deprecated. If the hook is superceded then the doc
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should describe the recommended replacement hook to register for.
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:ivar doc: The docs for using the hook.
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def __init__(self, name, doc, introduced, deprecated):
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"""Create a HookPoint.
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:param name: The name of the hook, for clients to use when registering.
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:param doc: The docs for the hook.
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:param introduced: When the hook was introduced (e.g. (0, 15)).
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:param deprecated: When the hook was deprecated, None for
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self.introduced = introduced
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self.deprecated = deprecated
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self._callback_names = {}
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"""Generate the documentation for this HookPoint.
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:return: A string terminated in \n.
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strings.append(self.name)
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strings.append('~'*len(self.name))
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introduced_string = _format_version_tuple(self.introduced)
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introduced_string = 'unknown'
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strings.append('Introduced in: %s' % introduced_string)
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deprecated_string = _format_version_tuple(self.deprecated)
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deprecated_string = 'Not deprecated'
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strings.append('Deprecated in: %s' % deprecated_string)
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strings.extend(textwrap.wrap(self.__doc__))
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return '\n'.join(strings)
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def __eq__(self, other):
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return (type(other) == type(self) and
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other.__dict__ == self.__dict__)
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def hook(self, callback, callback_label):
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"""Register a callback to be called when this HookPoint fires.
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:param callback: The callable to use when this HookPoint fires.
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:param callback_label: A label to show in the UI while this callback is
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self._callbacks.append(callback)
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if callback_label is not None:
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self._callback_names[callback] = callback_label
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return iter(self._callbacks)
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return len(self._callbacks)
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strings.append("<%s(" % type(self).__name__)
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strings.append(self.name)
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strings.append("), callbacks=[")
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for callback in self._callbacks:
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strings.append(repr(callback))
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strings.append(self._callback_names[callback])
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if len(self._callbacks) == 1:
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return ''.join(strings)
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A hook of type *xxx* of class *yyy* needs to be registered using::
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yyy.hooks.install_named_hook("xxx", ...)
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See `Using hooks`_ in the User Guide for examples.
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.. _Using hooks: ../user-guide/index.html#using-hooks
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The class that contains each hook is given before the hooks it supplies. For
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instance, BranchHooks as the class is the hooks class for
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`bzrlib.branch.Branch.hooks`.
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Each description also indicates whether the hook runs on the client (the
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machine where bzr was invoked) or the server (the machine addressed by
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the branch URL). These may be, but are not necessarily, the same machine.
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Plugins (including hooks) are run on the server if all of these is true:
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* The connection is via a smart server (accessed with a URL starting with
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"bzr://", "bzr+ssh://" or "bzr+http://", or accessed via a "http://"
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URL when a smart server is available via HTTP).
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* The hook is either server specific or part of general infrastructure rather
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than client specific code (such as commit).
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def hooks_help_text(topic):
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segments = [_help_prefix]
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for hook_key in sorted(known_hooks.keys()):
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hooks = known_hooks_key_to_object(hook_key)
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segments.append(hooks.docs())
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return '\n'.join(segments)
added
removed
bzrlib/hooks.py
