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
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
import venusian
from zope.interface import implements
from pyramid.interfaces import IContextFound
from pyramid.interfaces import INewRequest
from pyramid.interfaces import INewResponse
from pyramid.interfaces import IApplicationCreated
from pyramid.interfaces import IBeforeRender
class subscriber(object):
""" Decorator activated via a :term:`scan` which treats the
function being decorated as an event subscriber for the set of
interfaces passed as ``*ifaces`` to the decorator constructor.
For example:
.. code-block:: python
from pyramid.events import NewRequest
from pyramid.events import subscriber
@subscriber(NewRequest)
def mysubscriber(event):
event.request.foo = 1
More than one event type can be passed as a construtor argument. The
decorated subscriber will be called for each event type.
.. code-block:: python
from pyramid.events import NewRequest, NewResponse
from pyramid.events import subscriber
@subscriber(NewRequest, NewResponse)
def mysubscriber(event):
print event
When the ``subscriber`` decorator is used without passing an arguments,
the function it decorates is called for every event sent:
.. code-block:: python
from pyramid.events import subscriber
@subscriber()
def mysubscriber(event):
print event
This method will have no effect until a :term:`scan` is performed
against the package or module which contains it, ala:
.. code-block:: python
from pyramid.config import Configurator
config = Configurator()
config.scan('somepackage_containing_subscribers')
"""
venusian = venusian # for unit testing
def __init__(self, *ifaces):
self.ifaces = ifaces
def register(self, scanner, name, wrapped):
config = scanner.config
for iface in self.ifaces:
config.add_subscriber(wrapped, iface)
def __call__(self, wrapped):
self.venusian.attach(wrapped, self.register, category='pyramid')
return wrapped
class NewRequest(object):
""" An instance of this class is emitted as an :term:`event`
whenever :app:`Pyramid` begins to process a new request. The
even instance has an attribute, ``request``, which is a
:term:`request` object. This event class implements the
:class:`pyramid.interfaces.INewRequest` interface."""
implements(INewRequest)
def __init__(self, request):
self.request = request
class NewResponse(object):
""" An instance of this class is emitted as an :term:`event`
whenever any :app:`Pyramid` :term:`view` or :term:`exception
view` returns a :term:`response`.
The instance has two attributes:``request``, which is the request
which caused the response, and ``response``, which is the response
object returned by a view or renderer.
If the ``response`` was generated by an :term:`exception view`,
the request will have an attribute named ``exception``, which is
the exception object which caused the exception view to be
executed. If the response was generated by a 'normal' view, the
request will not have this attribute.
This event will not be generated if a response cannot be created
due to an exception that is not caught by an exception view (no
response is created under this circumstace).
This class implements the
:class:`pyramid.interfaces.INewResponse` interface.
.. note::
Postprocessing a response is usually better handled in a WSGI
:term:`middleware` component than in subscriber code that is
called by a :class:`pyramid.interfaces.INewResponse` event.
The :class:`pyramid.interfaces.INewResponse` event exists
almost purely for symmetry with the
:class:`pyramid.interfaces.INewRequest` event.
"""
implements(INewResponse)
def __init__(self, request, response):
self.request = request
self.response = response
class ContextFound(object):
""" An instance of this class is emitted as an :term:`event` after
the :app:`Pyramid` :term:`router` finds a :term:`context`
object (after it performs traversal) but before any view code is
executed. The instance has an attribute, ``request``, which is
the request object generated by :app:`Pyramid`.
Notably, the request object will have an attribute named
``context``, which is the context that will be provided to the
view which will eventually be called, as well as other attributes
attached by context-finding code.
This class implements the
:class:`pyramid.interfaces.IContextFound` interface.
.. note:: As of :app:`Pyramid` 1.0, for backwards compatibility
purposes, this event may also be imported as
:class:`pyramid.events.AfterTraversal`.
"""
implements(IContextFound)
def __init__(self, request):
self.request = request
AfterTraversal = ContextFound # b/c as of 1.0
class ApplicationCreated(object):
""" An instance of this class is emitted as an :term:`event` when
the :meth:`pyramid.config.Configurator.make_wsgi_app` is
called. The instance has an attribute, ``app``, which is an
instance of the :term:`router` that will handle WSGI requests.
This class implements the
:class:`pyramid.interfaces.IApplicationCreated` interface.
.. note:: For backwards compatibility purposes, this class can
also be imported as
:class:`pyramid.events.WSGIApplicationCreatedEvent`. This
was the name of the event class before :app:`Pyramid` 1.0.
"""
implements(IApplicationCreated)
def __init__(self, app):
self.app = app
self.object = app
WSGIApplicationCreatedEvent = ApplicationCreated # b/c (as of 1.0)
class BeforeRender(dict):
"""
Subscribers to this event may introspect the and modify the set of
:term:`renderer globals` before they are passed to a :term:`renderer`.
This event object iself has a dictionary-like interface that can be used
for this purpose. For example::
from repoze.events import subscriber
from pyramid.events import BeforeRender
@subscriber(BeforeRender)
def add_global(event):
event['mykey'] = 'foo'
An object of this type is sent as an event just before a :term:`renderer`
is invoked (but *after* the -- deprecated -- application-level renderer
globals factory added via
:class:`pyramid.config.Configurator.set_renderer_globals_factory`, if
any, has injected its own keys into the renderer globals dictionary).
If a subscriber adds a key via ``__setitem__`` or that already exists in
the renderer globals dictionary, it will overwrite an older value that is
already in the globals dictionary. This can be problematic because event
subscribers to the BeforeRender event do not possess any relative
ordering. For maximum interoperability with other third-party
subscribers, if you write an event subscriber meant to be used as a
BeforeRender subscriber, your subscriber code will need to (using
``.get`` or ``__contains__`` of the event object) ensure no value already
exists in the renderer globals dictionary before setting an overriding
value.
The event has an additional attribute named ``rendering_val``. This is
the (non-system) value returned by a view or passed to ``render*`` as
``value``. This feature is new in Pyramid 1.2.
See also :class:`pyramid.interfaces.IBeforeRender`.
"""
implements(IBeforeRender)
def __init__(self, system, rendering_val=None):
dict.__init__(self, system)
self.rendering_val = rendering_val
|
