File: introspector.rst

package info (click to toggle)
python-pyramid 1.6%2Bdfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 9,112 kB
  • ctags: 8,169
  • sloc: python: 41,764; makefile: 111; sh: 17
file content (593 lines) | stat: -rw-r--r-- 16,968 bytes parent folder | download
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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
.. index::
   single: introspection
   single: introspector

.. _using_introspection:

Pyramid Configuration Introspection
===================================

.. versionadded:: 1.3

When Pyramid starts up, each call to a :term:`configuration directive` causes
one or more :term:`introspectable` objects to be registered with an
:term:`introspector`.  The introspector can be queried by application code to
obtain information about the configuration of the running application.  This
feature is useful for debug toolbars, command-line scripts which show some
aspect of configuration, and for runtime reporting of startup-time
configuration settings.

Using the Introspector
----------------------

Here's an example of using Pyramid's introspector from within a view callable:

.. code-block:: python
    :linenos:

    from pyramid.view import view_config
    from pyramid.response import Response

    @view_config(route_name='bar')
    def show_current_route_pattern(request):
        introspector = request.registry.introspector
        route_name = request.matched_route.name
        route_intr = introspector.get('routes', route_name)
        return Response(str(route_intr['pattern']))

This view will return a response that contains the "pattern" argument provided
to the ``add_route`` method of the route which matched when the view was
called.  It uses the :meth:`pyramid.interfaces.IIntrospector.get` method to
return an introspectable in the category ``routes`` with a
:term:`discriminator` equal to the matched route name.  It then uses the
returned introspectable to obtain a "pattern" value.

The introspectable returned by the query methods of the introspector has
methods and attributes described by
:class:`pyramid.interfaces.IIntrospectable`.  In particular, the
:meth:`~pyramid.interfaces.IIntrospector.get`,
:meth:`~pyramid.interfaces.IIntrospector.get_category`,
:meth:`~pyramid.interfaces.IIntrospector.categories`,
:meth:`~pyramid.interfaces.IIntrospector.categorized`, and
:meth:`~pyramid.interfaces.IIntrospector.related` methods of an introspector
can be used to query for introspectables.

Introspectable Objects
----------------------

Introspectable objects are returned from query methods of an introspector. Each
introspectable object implements the attributes and methods documented at
:class:`pyramid.interfaces.IIntrospectable`.

The important attributes shared by all introspectables are the following:

``title``

  A human-readable text title describing the introspectable

``category_name``

  A text category name describing the introspection category to which this
  introspectable belongs.  It is often a plural if there are expected to be
  more than one introspectable registered within the category.

``discriminator``

  A hashable object representing the unique value of this introspectable within
  its category.

``discriminator_hash``

  The integer hash of the discriminator (useful in HTML links).

``type_name``

  The text name of a subtype within this introspectable's category.  If there
  is only one type name in this introspectable's category, this value will
  often be a singular version of the category name but it can be an arbitrary
  value.

``action_info``

  An object describing the directive call site which caused this introspectable
  to be registered.  It contains attributes described in
  :class:`pyramid.interfaces.IActionInfo`.

Besides having the attributes described above, an introspectable is a
dictionary-like object.  An introspectable can be queried for data values via
its ``__getitem__``, ``get``, ``keys``, ``values``, or ``items`` methods.
For example:

.. code-block:: python
    :linenos:

    route_intr = introspector.get('routes', 'edit_user')
    pattern = route_intr['pattern']

Pyramid Introspection Categories
--------------------------------

The list of concrete introspection categories provided by built-in Pyramid
configuration directives follows.  Add-on packages may supply other
introspectables in categories not described here.

``subscribers``

  Each introspectable in the ``subscribers`` category represents a call to
  :meth:`pyramid.config.Configurator.add_subscriber` (or the decorator
  equivalent).  Each will have the following data.

  ``subscriber``

    The subscriber callable object (the resolution of the ``subscriber``
    argument passed to ``add_subscriber``).

  ``interfaces``

    A sequence of interfaces (or classes) that are subscribed to (the
    resolution of the ``ifaces`` argument passed to ``add_subscriber``).

  ``derived_subscriber``

    A wrapper around the subscriber used internally by the system so it can
    call it with more than one argument if your original subscriber accepts
    only one.

  ``predicates``

    The predicate objects created as the result of passing predicate arguments
    to ``add_subscriber``.

  ``derived_predicates``

    Wrappers around the predicate objects created as the result of passing
    predicate arguments to ``add_subscriber`` (to be used when predicates take
    only one value but must be passed more than one).

``response adapters``

  Each introspectable in the ``response adapters`` category represents a call
  to :meth:`pyramid.config.Configurator.add_response_adapter` (or a decorator
  equivalent).  Each will have the following data.

  ``adapter``

    The adapter object (the resolved ``adapter`` argument to
    ``add_response_adapter``).

  ``type``

    The resolved ``type_or_iface`` argument passed to ``add_response_adapter``.

``root factories``

  Each introspectable in the ``root factories`` category represents a call to
  :meth:`pyramid.config.Configurator.set_root_factory` (or the Configurator
  constructor equivalent) *or* a ``factory`` argument passed to
  :meth:`pyramid.config.Configurator.add_route`.  Each will have the following
  data.

  ``factory``

    The factory object (the resolved ``factory`` argument to
    ``set_root_factory``).

  ``route_name``

    The name of the route which will use this factory.  If this is the
    *default* root factory (if it's registered during a call to
    ``set_root_factory``), this value will be ``None``.

``session factory``

  Only one introspectable will exist in the ``session factory`` category.  It
  represents a call to :meth:`pyramid.config.Configurator.set_session_factory`
  (or the Configurator constructor equivalent).  It will have the following
  data.

  ``factory``

    The factory object (the resolved ``factory`` argument to
    ``set_session_factory``).

``request factory``

  Only one introspectable will exist in the ``request factory`` category.  It
  represents a call to :meth:`pyramid.config.Configurator.set_request_factory`
  (or the Configurator constructor equivalent).  It will have the following
  data.

  ``factory``

    The factory object (the resolved ``factory`` argument to
    ``set_request_factory``).

``locale negotiator``

  Only one introspectable will exist in the ``locale negotiator`` category.  It
  represents a call to
  :meth:`pyramid.config.Configurator.set_locale_negotiator` (or the
  Configurator constructor equivalent).  It will have the following data.

  ``negotiator``

    The factory object (the resolved ``negotiator`` argument to
    ``set_locale_negotiator``).

``renderer factories``

  Each introspectable in the ``renderer factories`` category represents a call
  to :meth:`pyramid.config.Configurator.add_renderer` (or the Configurator
  constructor equivalent).  Each will have the following data.

  ``name``

    The name of the renderer (the value of the ``name`` argument to
    ``add_renderer``).

  ``factory``

    The factory object (the resolved ``factory`` argument to ``add_renderer``).

``routes``

  Each introspectable in the ``routes`` category represents a call to
  :meth:`pyramid.config.Configurator.add_route`.  Each will have the following
  data.

  ``name``

    The ``name`` argument passed to ``add_route``.

  ``pattern``

    The ``pattern`` argument passed to ``add_route``.

  ``factory``

    The (resolved) ``factory`` argument passed to ``add_route``.

  ``xhr``

    The ``xhr`` argument passed to ``add_route``.

  ``request_method``

    The ``request_method`` argument passed to ``add_route``.

  ``request_methods``

    A sequence of request method names implied by the ``request_method``
    argument passed to ``add_route`` or the value ``None`` if a
    ``request_method`` argument was not supplied.

  ``path_info``

    The ``path_info`` argument passed to ``add_route``.

  ``request_param``

    The ``request_param`` argument passed to ``add_route``.

  ``header``

    The ``header`` argument passed to ``add_route``.

  ``accept``

    The ``accept`` argument passed to ``add_route``.

  ``traverse``

    The ``traverse`` argument passed to ``add_route``.

  ``custom_predicates``

    The ``custom_predicates`` argument passed to ``add_route``.

  ``pregenerator``

    The ``pregenerator`` argument passed to ``add_route``.

  ``static``

    The ``static`` argument passed to ``add_route``.

  ``use_global_views``

    The ``use_global_views`` argument passed to ``add_route``.

  ``object``

     The :class:`pyramid.interfaces.IRoute` object that is used to perform
     matching and generation for this route.

``authentication policy``

  There will be one and only one introspectable in the ``authentication
  policy`` category.  It represents a call to the
  :meth:`pyramid.config.Configurator.set_authentication_policy` method (or
  its Configurator constructor equivalent).  It will have the following data.

  ``policy``

    The policy object (the resolved ``policy`` argument to
    ``set_authentication_policy``).

``authorization policy``

  There will be one and only one introspectable in the ``authorization policy``
  category.  It represents a call to the
  :meth:`pyramid.config.Configurator.set_authorization_policy` method (or its
  Configurator constructor equivalent).  It will have the following data.

  ``policy``

    The policy object (the resolved ``policy`` argument to
    ``set_authorization_policy``).

``default permission``

  There will be one and only one introspectable in the ``default permission``
  category.  It represents a call to the
  :meth:`pyramid.config.Configurator.set_default_permission` method (or its
  Configurator constructor equivalent).  It will have the following data.

  ``value``

    The permission name passed to ``set_default_permission``.

``views``

  Each introspectable in the ``views`` category represents a call to
  :meth:`pyramid.config.Configurator.add_view`.  Each will have the following
  data.

  ``name``

    The ``name`` argument passed to ``add_view``.

  ``context``

    The (resolved) ``context`` argument passed to ``add_view``.

  ``containment``

    The (resolved) ``containment`` argument passed to ``add_view``.

  ``request_param``

    The ``request_param`` argument passed to ``add_view``.

  ``request_methods``

    A sequence of request method names implied by the ``request_method``
    argument passed to ``add_view`` or the value ``None`` if a
    ``request_method`` argument was not supplied.

  ``route_name``

    The ``route_name`` argument passed to ``add_view``.

  ``attr``

    The ``attr`` argument passed to ``add_view``.

  ``xhr``

    The ``xhr`` argument passed to ``add_view``.

  ``accept``

    The ``accept`` argument passed to ``add_view``.

  ``header``

    The ``header`` argument passed to ``add_view``.

  ``path_info``

    The ``path_info`` argument passed to ``add_view``.

  ``match_param``

    The ``match_param`` argument passed to ``add_view``.

  ``csrf_token``

    The ``csrf_token`` argument passed to ``add_view``.

  ``callable``

    The (resolved) ``view`` argument passed to ``add_view``.  Represents the
    "raw" view callable.

  ``derived_callable``

    The view callable derived from the ``view`` argument passed to
    ``add_view``.  Represents the view callable which Pyramid itself calls
    (wrapped in security and other wrappers).

  ``mapper``

    The (resolved) ``mapper`` argument passed to ``add_view``.

  ``decorator``

    The (resolved) ``decorator`` argument passed to ``add_view``.

``permissions``

  Each introspectable in the ``permissions`` category represents a call to
  :meth:`pyramid.config.Configurator.add_view` that has an explicit
  ``permission`` argument *or* a call to
  :meth:`pyramid.config.Configurator.set_default_permission`.  Each will have
  the following data.

  ``value``

    The permission name passed to ``add_view`` or ``set_default_permission``.

``templates``

  Each introspectable in the ``templates`` category represents a call to
  :meth:`pyramid.config.Configurator.add_view` that has a ``renderer``
  argument which points to a template.  Each will have the following data.

  ``name``

    The renderer's name (a string).

  ``type``

    The renderer's type (a string).

  ``renderer``

    The :class:`pyramid.interfaces.IRendererInfo` object which represents this
    template's renderer.

``view mappers``

  Each introspectable in the ``view mappers`` category represents a call to
  :meth:`pyramid.config.Configurator.add_view` that has an explicit ``mapper``
  argument *or* a call to
  :meth:`pyramid.config.Configurator.set_view_mapper`.  Each will have
  the following data.

  ``mapper``

    The (resolved) ``mapper`` argument passed to ``add_view`` or
    ``set_view_mapper``.

``asset overrides``

  Each introspectable in the ``asset overrides`` category represents a call to
  :meth:`pyramid.config.Configurator.override_asset`.  Each will have the
  following data.

  ``to_override``

    The ``to_override`` argument (an asset spec) passed to ``override_asset``.

  ``override_with``

    The ``override_with`` argument (an asset spec) passed to
    ``override_asset``.

``translation directories``

  Each introspectable in the ``translation directories`` category represents an
  individual element in a ``specs`` argument passed to
  :meth:`pyramid.config.Configurator.add_translation_dirs`.  Each will have the
  following data.

  ``directory``

    The absolute path of the translation directory.

  ``spec``

    The asset specification passed to ``add_translation_dirs``.

``tweens``

  Each introspectable in the ``tweens`` category represents a call to
  :meth:`pyramid.config.Configurator.add_tween`.  Each will have the following
  data.

  ``name``

    The dotted name to the tween factory as a string (passed as the
    ``tween_factory`` argument to ``add_tween``).

  ``factory``

    The (resolved) tween factory object.

  ``type``

    ``implicit`` or ``explicit`` as a string.

  ``under``

     The ``under`` argument passed to ``add_tween`` (a string).

  ``over``

     The ``over`` argument passed to ``add_tween`` (a string).

``static views``

  Each introspectable in the ``static views`` category represents a call to
  :meth:`pyramid.config.Configurator.add_static_view`.  Each will have the
  following data.

  ``name``

    The ``name`` argument provided to ``add_static_view``.

  ``spec``

    A normalized version of the ``spec`` argument provided to
    ``add_static_view``.

``traversers``

  Each introspectable in the ``traversers`` category represents a call to
  :meth:`pyramid.config.Configurator.add_traverser`.  Each will have the
  following data.

  ``iface``

    The (resolved) interface or class object that represents the return value
    of a root factory for which this traverser will be used.

  ``adapter``

    The (resolved) traverser class.

``resource url adapters``

  Each introspectable in the ``resource url adapters`` category represents a
  call to :meth:`pyramid.config.Configurator.add_resource_url_adapter`.  Each
  will have the following data.

  ``adapter``

    The (resolved) resource URL adapter class.

  ``resource_iface``

    The (resolved) interface or class object that represents the resource
    interface for which this URL adapter is registered.

  ``request_iface``

    The (resolved) interface or class object that represents the request
    interface for which this URL adapter is registered.

Introspection in the Toolbar
----------------------------

The Pyramid debug toolbar (part of the ``pyramid_debugtoolbar`` package)
provides a canned view of all registered introspectables and their
relationships.  It is currently under the "Global" tab in the main navigation,
and it looks something like this:

.. image:: tb_introspector.png

Disabling Introspection
-----------------------

You can disable Pyramid introspection by passing the flag
``introspection=False`` to the :term:`Configurator` constructor in your
application setup:

.. code-block:: python

   from pyramid.config import Configurator
   config = Configurator(..., introspection=False)

When ``introspection`` is ``False``, all introspectables generated by
configuration directives are thrown away.