1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from .named import NamedExtensionManager
class HookManager(NamedExtensionManager):
"""Coordinate execution of multiple extensions using a common name.
:param namespace: The namespace for the entry points.
:type namespace: str
:param name: The name of the hooks to load.
:type name: str
:param invoke_on_load: Boolean controlling whether to invoke the
object returned by the entry point after the driver is loaded.
:type invoke_on_load: bool
:param invoke_args: Positional arguments to pass when invoking
the object returned by the entry point. Only used if invoke_on_load
is True.
:type invoke_args: tuple
:param invoke_kwds: Named arguments to pass when invoking
the object returned by the entry point. Only used if invoke_on_load
is True.
:type invoke_kwds: dict
:param on_load_failure_callback: Callback function that will be called when
a entrypoint can not be loaded. The arguments that will be provided
when this is called (when an entrypoint fails to load) are
(manager, entrypoint, exception)
:type on_load_failure_callback: function
:param verify_requirements: Use setuptools to enforce the
dependencies of the plugin(s) being loaded. Defaults to False.
:type verify_requirements: bool
:type on_missing_entrypoints_callback: function
:param warn_on_missing_entrypoint: Flag to control whether failing
to load a plugin is reported via a log mess. Only applies if
on_missing_entrypoints_callback is None.
:type warn_on_missing_entrypoint: bool
"""
def __init__(self, namespace, name,
invoke_on_load=False, invoke_args=(), invoke_kwds={},
on_load_failure_callback=None,
verify_requirements=False,
on_missing_entrypoints_callback=None,
# NOTE(dhellmann): This default is different from the
# base class because for hooks it is less likely to
# be an error to have no entry points present.
warn_on_missing_entrypoint=False):
super(HookManager, self).__init__(
namespace,
[name],
invoke_on_load=invoke_on_load,
invoke_args=invoke_args,
invoke_kwds=invoke_kwds,
on_load_failure_callback=on_load_failure_callback,
on_missing_entrypoints_callback=on_missing_entrypoints_callback,
verify_requirements=verify_requirements,
warn_on_missing_entrypoint=warn_on_missing_entrypoint,
)
def _init_attributes(self, namespace, names, name_order=False,
propagate_map_exceptions=False,
on_load_failure_callback=None):
super(HookManager, self)._init_attributes(
namespace, names,
propagate_map_exceptions=propagate_map_exceptions,
on_load_failure_callback=on_load_failure_callback)
self._name = names[0]
def __getitem__(self, name):
"""Return the named extensions.
Accessing a HookManager as a dictionary (``em['name']``)
produces a list of the :class:`Extension` instance(s) with the
specified name, in the order they would be invoked by map().
"""
if name != self._name:
raise KeyError(name)
return self.extensions
|
