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
|
# 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.
import logging
from .extension import ExtensionManager
LOG = logging.getLogger(__name__)
class EnabledExtensionManager(ExtensionManager):
"""Loads only plugins that pass a check function.
The check_func argument should return a boolean, with ``True``
indicating that the extension should be loaded and made available
and ``False`` indicating that the extension should be ignored.
:param namespace: The namespace for the entry points.
:type namespace: str
:param check_func: Function to determine which extensions to load.
:type check_func: callable, taking an :class:`Extension`
instance as argument
: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 propagate_map_exceptions: Boolean controlling whether exceptions
are propagated up through the map call or whether they are logged and
then ignored
:type propagate_map_exceptions: bool
: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
"""
def __init__(self, namespace, check_func, invoke_on_load=False,
invoke_args=(), invoke_kwds={},
propagate_map_exceptions=False,
on_load_failure_callback=None,
verify_requirements=False,):
self.check_func = check_func
super(EnabledExtensionManager, self).__init__(
namespace,
invoke_on_load=invoke_on_load,
invoke_args=invoke_args,
invoke_kwds=invoke_kwds,
propagate_map_exceptions=propagate_map_exceptions,
on_load_failure_callback=on_load_failure_callback,
verify_requirements=verify_requirements,
)
def _load_one_plugin(self, ep, invoke_on_load, invoke_args, invoke_kwds,
verify_requirements):
ext = super(EnabledExtensionManager, self)._load_one_plugin(
ep, invoke_on_load, invoke_args, invoke_kwds,
verify_requirements,
)
if ext and not self.check_func(ext):
LOG.debug('ignoring extension %r', ep.name)
return None
return ext
|
