forked from Pylons/pyramid
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views.py
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views.py
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import functools
import inspect
import posixpath
import operator
import os
import warnings
from urllib.parse import quote, urljoin, urlparse, urlunparse
from webob.acceptparse import Accept
from zope.interface import Interface, implementedBy, implementer
from zope.interface.interfaces import IInterface
from pyramid.interfaces import (
IAcceptOrder,
IExceptionViewClassifier,
IException,
IMultiView,
IPackageOverrides,
IRendererFactory,
IRequest,
IResponse,
IRouteRequest,
ISecuredView,
IStaticURLInfo,
IView,
IViewClassifier,
IViewDerivers,
IViewDeriverInfo,
IViewMapperFactory,
PHASE1_CONFIG,
)
from pyramid import renderers
from pyramid.asset import resolve_asset_spec
from pyramid.decorator import reify
from pyramid.exceptions import ConfigurationError, PredicateMismatch
from pyramid.httpexceptions import (
HTTPForbidden,
HTTPNotFound,
default_exceptionresponse_view,
)
from pyramid.registry import Deferred
from pyramid.security import NO_PERMISSION_REQUIRED
from pyramid.static import static_view
from pyramid.url import parse_url_overrides
from pyramid.view import AppendSlashNotFoundViewFactory
from pyramid.util import (
as_sorted_tuple,
is_nonstr_iter,
TopologicalSorter,
WIN,
)
import pyramid.predicates
import pyramid.viewderivers
from pyramid.viewderivers import (
INGRESS,
VIEW,
preserve_view_attrs,
view_description,
requestonly,
DefaultViewMapper,
wraps_view,
)
from pyramid.config.actions import action_method
from pyramid.config.predicates import (
DEFAULT_PHASH,
MAX_ORDER,
normalize_accept_offer,
predvalseq,
sort_accept_offers,
)
DefaultViewMapper = DefaultViewMapper # bw-compat
preserve_view_attrs = preserve_view_attrs # bw-compat
requestonly = requestonly # bw-compat
view_description = view_description # bw-compat
@implementer(IMultiView)
class MultiView(object):
def __init__(self, name):
self.name = name
self.media_views = {}
self.views = []
self.accepts = []
def __discriminator__(self, context, request):
# used by introspection systems like so:
# view = adapters.lookup(....)
# view.__discriminator__(context, request) -> view's discriminator
# so that superdynamic systems can feed the discriminator to
# the introspection system to get info about it
view = self.match(context, request)
return view.__discriminator__(context, request)
def add(self, view, order, phash=None, accept=None, accept_order=None):
if phash is not None:
for i, (s, v, h) in enumerate(list(self.views)):
if phash == h:
self.views[i] = (order, view, phash)
return
if accept is None:
self.views.append((order, view, phash))
self.views.sort(key=operator.itemgetter(0))
else:
subset = self.media_views.setdefault(accept, [])
for i, (s, v, h) in enumerate(list(subset)):
if phash == h:
subset[i] = (order, view, phash)
return
else:
subset.append((order, view, phash))
subset.sort(key=operator.itemgetter(0))
# dedupe accepts and sort appropriately
accepts = set(self.accepts)
accepts.add(accept)
if accept_order:
accept_order = [v for _, v in accept_order.sorted()]
self.accepts = sort_accept_offers(accepts, accept_order)
def get_views(self, request):
if self.accepts and hasattr(request, 'accept'):
views = []
for offer, _ in request.accept.acceptable_offers(self.accepts):
views.extend(self.media_views[offer])
views.extend(self.views)
return views
return self.views
def match(self, context, request):
for order, view, phash in self.get_views(request):
if not hasattr(view, '__predicated__'):
return view
if view.__predicated__(context, request):
return view
raise PredicateMismatch(self.name)
def __permitted__(self, context, request):
view = self.match(context, request)
if hasattr(view, '__permitted__'):
return view.__permitted__(context, request)
return True
def __call_permissive__(self, context, request):
view = self.match(context, request)
view = getattr(view, '__call_permissive__', view)
return view(context, request)
def __call__(self, context, request):
for order, view, phash in self.get_views(request):
try:
return view(context, request)
except PredicateMismatch:
continue
raise PredicateMismatch(self.name)
def attr_wrapped_view(view, info):
accept, order, phash = (
info.options.get('accept', None),
getattr(info, 'order', MAX_ORDER),
getattr(info, 'phash', DEFAULT_PHASH),
)
# this is a little silly but we don't want to decorate the original
# function with attributes that indicate accept, order, and phash,
# so we use a wrapper
if (accept is None) and (order == MAX_ORDER) and (phash == DEFAULT_PHASH):
return view # defaults
def attr_view(context, request):
return view(context, request)
attr_view.__accept__ = accept
attr_view.__order__ = order
attr_view.__phash__ = phash
attr_view.__view_attr__ = info.options.get('attr')
attr_view.__permission__ = info.options.get('permission')
return attr_view
attr_wrapped_view.options = ('accept', 'attr', 'permission')
def predicated_view(view, info):
preds = info.predicates
if not preds:
return view
def predicate_wrapper(context, request):
for predicate in preds:
if not predicate(context, request):
view_name = getattr(view, '__name__', view)
raise PredicateMismatch(
'predicate mismatch for view %s (%s)'
% (view_name, predicate.text())
)
return view(context, request)
def checker(context, request):
return all((predicate(context, request) for predicate in preds))
predicate_wrapper.__predicated__ = checker
predicate_wrapper.__predicates__ = preds
return predicate_wrapper
def viewdefaults(wrapped):
""" Decorator for add_view-like methods which takes into account
__view_defaults__ attached to view it is passed. Not a documented API but
used by some external systems."""
def wrapper(self, *arg, **kw):
defaults = {}
if arg:
view = arg[0]
else:
view = kw.get('view')
view = self.maybe_dotted(view)
if inspect.isclass(view):
defaults = getattr(view, '__view_defaults__', {}).copy()
if '_backframes' not in kw:
kw['_backframes'] = 1 # for action_method
defaults.update(kw)
return wrapped(self, *arg, **defaults)
return functools.wraps(wrapped)(wrapper)
def combine_decorators(*decorators):
def decorated(view_callable):
# reversed() allows a more natural ordering in the api
for decorator in reversed(decorators):
view_callable = decorator(view_callable)
return view_callable
return decorated
class ViewsConfiguratorMixin(object):
@viewdefaults
@action_method
def add_view(
self,
view=None,
name="",
for_=None,
permission=None,
request_type=None,
route_name=None,
request_method=None,
request_param=None,
containment=None,
attr=None,
renderer=None,
wrapper=None,
xhr=None,
accept=None,
header=None,
path_info=None,
custom_predicates=(),
context=None,
decorator=None,
mapper=None,
http_cache=None,
match_param=None,
require_csrf=None,
exception_only=False,
**view_options
):
""" Add a :term:`view configuration` to the current
configuration state. Arguments to ``add_view`` are broken
down below into *predicate* arguments and *non-predicate*
arguments. Predicate arguments narrow the circumstances in
which the view callable will be invoked when a request is
presented to :app:`Pyramid`; non-predicate arguments are
informational.
Non-Predicate Arguments
view
A :term:`view callable` or a :term:`dotted Python name`
which refers to a view callable. This argument is required
unless a ``renderer`` argument also exists. If a
``renderer`` argument is passed, and a ``view`` argument is
not provided, the view callable defaults to a callable that
returns an empty dictionary (see
:ref:`views_which_use_a_renderer`).
permission
A :term:`permission` that the user must possess in order to invoke
the :term:`view callable`. See :ref:`view_security_section` for
more information about view security and permissions. This is
often a string like ``view`` or ``edit``.
If ``permission`` is omitted, a *default* permission may be used
for this view registration if one was named as the
:class:`pyramid.config.Configurator` constructor's
``default_permission`` argument, or if
:meth:`pyramid.config.Configurator.set_default_permission` was used
prior to this view registration. Pass the value
:data:`pyramid.security.NO_PERMISSION_REQUIRED` as the permission
argument to explicitly indicate that the view should always be
executable by entirely anonymous users, regardless of the default
permission, bypassing any :term:`authorization policy` that may be
in effect.
attr
This knob is most useful when the view definition is a class.
The view machinery defaults to using the ``__call__`` method
of the :term:`view callable` (or the function itself, if the
view callable is a function) to obtain a response. The
``attr`` value allows you to vary the method attribute used
to obtain the response. For example, if your view was a
class, and the class has a method named ``index`` and you
wanted to use this method instead of the class' ``__call__``
method to return the response, you'd say ``attr="index"`` in the
view configuration for the view.
renderer
This is either a single string term (e.g. ``json``) or a
string implying a path or :term:`asset specification`
(e.g. ``templates/views.pt``) naming a :term:`renderer`
implementation. If the ``renderer`` value does not contain
a dot ``.``, the specified string will be used to look up a
renderer implementation, and that renderer implementation
will be used to construct a response from the view return
value. If the ``renderer`` value contains a dot (``.``),
the specified term will be treated as a path, and the
filename extension of the last element in the path will be
used to look up the renderer implementation, which will be
passed the full path. The renderer implementation will be
used to construct a :term:`response` from the view return
value.
Note that if the view itself returns a :term:`response` (see
:ref:`the_response`), the specified renderer implementation
is never called.
When the renderer is a path, although a path is usually just
a simple relative pathname (e.g. ``templates/foo.pt``,
implying that a template named "foo.pt" is in the
"templates" directory relative to the directory of the
current :term:`package` of the Configurator), a path can be
absolute, starting with a slash on UNIX or a drive letter
prefix on Windows. The path can alternately be a
:term:`asset specification` in the form
``some.dotted.package_name:relative/path``, making it
possible to address template assets which live in a
separate package.
The ``renderer`` attribute is optional. If it is not
defined, the "null" renderer is assumed (no rendering is
performed and the value is passed back to the upstream
:app:`Pyramid` machinery unmodified).
http_cache
.. versionadded:: 1.1
When you supply an ``http_cache`` value to a view configuration,
the ``Expires`` and ``Cache-Control`` headers of a response
generated by the associated view callable are modified. The value
for ``http_cache`` may be one of the following:
- A nonzero integer. If it's a nonzero integer, it's treated as a
number of seconds. This number of seconds will be used to
compute the ``Expires`` header and the ``Cache-Control:
max-age`` parameter of responses to requests which call this view.
For example: ``http_cache=3600`` instructs the requesting browser
to 'cache this response for an hour, please'.
- A ``datetime.timedelta`` instance. If it's a
``datetime.timedelta`` instance, it will be converted into a
number of seconds, and that number of seconds will be used to
compute the ``Expires`` header and the ``Cache-Control:
max-age`` parameter of responses to requests which call this view.
For example: ``http_cache=datetime.timedelta(days=1)`` instructs
the requesting browser to 'cache this response for a day, please'.
- Zero (``0``). If the value is zero, the ``Cache-Control`` and
``Expires`` headers present in all responses from this view will
be composed such that client browser cache (and any intermediate
caches) are instructed to never cache the response.
- A two-tuple. If it's a two tuple (e.g. ``http_cache=(1,
{'public':True})``), the first value in the tuple may be a
nonzero integer or a ``datetime.timedelta`` instance; in either
case this value will be used as the number of seconds to cache
the response. The second value in the tuple must be a
dictionary. The values present in the dictionary will be used as
input to the ``Cache-Control`` response header. For example:
``http_cache=(3600, {'public':True})`` means 'cache for an hour,
and add ``public`` to the Cache-Control header of the response'.
All keys and values supported by the
``webob.cachecontrol.CacheControl`` interface may be added to the
dictionary. Supplying ``{'public':True}`` is equivalent to
calling ``response.cache_control.public = True``.
Providing a non-tuple value as ``http_cache`` is equivalent to
calling ``response.cache_expires(value)`` within your view's body.
Providing a two-tuple value as ``http_cache`` is equivalent to
calling ``response.cache_expires(value[0], **value[1])`` within your
view's body.
If you wish to avoid influencing, the ``Expires`` header, and
instead wish to only influence ``Cache-Control`` headers, pass a
tuple as ``http_cache`` with the first element of ``None``, e.g.:
``(None, {'public':True})``.
If you wish to prevent a view that uses ``http_cache`` in its
configuration from having its caching response headers changed by
this machinery, set ``response.cache_control.prevent_auto = True``
before returning the response from the view. This effectively
disables any HTTP caching done by ``http_cache`` for that response.
require_csrf
.. versionadded:: 1.7
A boolean option or ``None``. Default: ``None``.
If this option is set to ``True`` then CSRF checks will be enabled
for requests to this view. The required token or header default to
``csrf_token`` and ``X-CSRF-Token``, respectively.
CSRF checks only affect "unsafe" methods as defined by RFC2616. By
default, these methods are anything except
``GET``, ``HEAD``, ``OPTIONS``, and ``TRACE``.
The defaults here may be overridden by
:meth:`pyramid.config.Configurator.set_default_csrf_options`.
This feature requires a configured :term:`session factory`.
If this option is set to ``False`` then CSRF checks will be disabled
regardless of the default ``require_csrf`` setting passed
to ``set_default_csrf_options``.
See :ref:`auto_csrf_checking` for more information.
wrapper
The :term:`view name` of a different :term:`view
configuration` which will receive the response body of this
view as the ``request.wrapped_body`` attribute of its own
:term:`request`, and the :term:`response` returned by this
view as the ``request.wrapped_response`` attribute of its
own request. Using a wrapper makes it possible to "chain"
views together to form a composite response. The response
of the outermost wrapper view will be returned to the user.
The wrapper view will be found as any view is found: see
:ref:`view_lookup`. The "best" wrapper view will be found
based on the lookup ordering: "under the hood" this wrapper
view is looked up via
``pyramid.view.render_view_to_response(context, request,
'wrapper_viewname')``. The context and request of a wrapper
view is the same context and request of the inner view. If
this attribute is unspecified, no view wrapping is done.
decorator
A :term:`dotted Python name` to function (or the function itself,
or an iterable of the aforementioned) which will be used to
decorate the registered :term:`view callable`. The decorator
function(s) will be called with the view callable as a single
argument. The view callable it is passed will accept
``(context, request)``. The decorator(s) must return a
replacement view callable which also accepts ``(context,
request)``.
If decorator is an iterable, the callables will be combined and
used in the order provided as a decorator.
For example::
@view_config(...,
decorator=(decorator2,
decorator1))
def myview(request):
....
Is similar to doing::
@view_config(...)
@decorator2
@decorator1
def myview(request):
...
Except with the existing benefits of ``decorator=`` (having a common
decorator syntax for all view calling conventions and not having to
think about preserving function attributes such as ``__name__`` and
``__module__`` within decorator logic).
An important distinction is that each decorator will receive a
response object implementing :class:`pyramid.interfaces.IResponse`
instead of the raw value returned from the view callable. All
decorators in the chain must return a response object or raise an
exception:
.. code-block:: python
def log_timer(wrapped):
def wrapper(context, request):
start = time.time()
response = wrapped(context, request)
duration = time.time() - start
response.headers['X-View-Time'] = '%.3f' % (duration,)
log.info('view took %.3f seconds', duration)
return response
return wrapper
.. versionchanged:: 1.4a4
Passing an iterable.
mapper
A Python object or :term:`dotted Python name` which refers to a
:term:`view mapper`, or ``None``. By default it is ``None``, which
indicates that the view should use the default view mapper. This
plug-point is useful for Pyramid extension developers, but it's not
very useful for 'civilians' who are just developing stock Pyramid
applications. Pay no attention to the man behind the curtain.
accept
A :term:`media type` that will be matched against the ``Accept``
HTTP request header. If this value is specified, it must be a
specific media type such as ``text/html`` or ``text/html;level=1``.
If the media type is acceptable by the ``Accept`` header of the
request, or if the ``Accept`` header isn't set at all in the request,
this predicate will match. If this does not match the ``Accept``
header of the request, view matching continues.
If ``accept`` is not specified, the ``HTTP_ACCEPT`` HTTP header is
not taken into consideration when deciding whether or not to invoke
the associated view callable.
The ``accept`` argument is technically not a predicate and does
not support wrapping with :func:`pyramid.config.not_`.
See :ref:`accept_content_negotiation` for more information.
.. versionchanged:: 1.10
Specifying a media range is deprecated and will be removed in
:app:`Pyramid` 2.0. Use explicit media types to avoid any
ambiguities in content negotiation.
.. versionchanged:: 2.0
Removed support for media ranges.
exception_only
.. versionadded:: 1.8
When this value is ``True``, the ``context`` argument must be
a subclass of ``Exception``. This flag indicates that only an
:term:`exception view` should be created, and that this view should
not match if the traversal :term:`context` matches the ``context``
argument. If the ``context`` is a subclass of ``Exception`` and
this value is ``False`` (the default), then a view will be
registered to match the traversal :term:`context` as well.
Predicate Arguments
name
The :term:`view name`. Read :ref:`traversal_chapter` to
understand the concept of a view name.
context
An object or a :term:`dotted Python name` referring to an
interface or class object that the :term:`context` must be
an instance of, *or* the :term:`interface` that the
:term:`context` must provide in order for this view to be
found and called. This predicate is true when the
:term:`context` is an instance of the represented class or
if the :term:`context` provides the represented interface;
it is otherwise false. This argument may also be provided
to ``add_view`` as ``for_`` (an older, still-supported
spelling). If the view should *only* match when handling
exceptions, then set the ``exception_only`` to ``True``.
route_name
This value must match the ``name`` of a :term:`route
configuration` declaration (see :ref:`urldispatch_chapter`)
that must match before this view will be called.
request_type
This value should be an :term:`interface` that the
:term:`request` must provide in order for this view to be
found and called. This value exists only for backwards
compatibility purposes.
request_method
This value can be either a string (such as ``"GET"``, ``"POST"``,
``"PUT"``, ``"DELETE"``, ``"HEAD"`` or ``"OPTIONS"``) representing
an HTTP ``REQUEST_METHOD``, or a tuple containing one or more of
these strings. A view declaration with this argument ensures that
the view will only be called when the ``method`` attribute of the
request (aka the ``REQUEST_METHOD`` of the WSGI environment) matches
a supplied value. Note that use of ``GET`` also implies that the
view will respond to ``HEAD`` as of Pyramid 1.4.
.. versionchanged:: 1.2
The ability to pass a tuple of items as ``request_method``.
Previous versions allowed only a string.
request_param
This value can be any string or any sequence of strings. A view
declaration with this argument ensures that the view will only be
called when the :term:`request` has a key in the ``request.params``
dictionary (an HTTP ``GET`` or ``POST`` variable) that has a
name which matches the supplied value (if the value is a string)
or values (if the value is a tuple). If any value
supplied has a ``=`` sign in it,
e.g. ``request_param="foo=123"``, then the key (``foo``)
must both exist in the ``request.params`` dictionary, *and*
the value must match the right hand side of the expression
(``123``) for the view to "match" the current request.
match_param
.. versionadded:: 1.2
This value can be a string of the format "key=value" or a tuple
containing one or more of these strings.
A view declaration with this argument ensures that the view will
only be called when the :term:`request` has key/value pairs in its
:term:`matchdict` that equal those supplied in the predicate.
e.g. ``match_param="action=edit"`` would require the ``action``
parameter in the :term:`matchdict` match the right hand side of
the expression (``edit``) for the view to "match" the current
request.
If the ``match_param`` is a tuple, every key/value pair must match
for the predicate to pass.
containment
This value should be a Python class or :term:`interface` (or a
:term:`dotted Python name`) that an object in the
:term:`lineage` of the context must provide in order for this view
to be found and called. The nodes in your object graph must be
"location-aware" to use this feature. See
:ref:`location_aware` for more information about
location-awareness.
xhr
This value should be either ``True`` or ``False``. If this
value is specified and is ``True``, the :term:`request`
must possess an ``HTTP_X_REQUESTED_WITH`` (aka
``X-Requested-With``) header that has the value
``XMLHttpRequest`` for this view to be found and called.
This is useful for detecting AJAX requests issued from
jQuery, Prototype and other Javascript libraries.
header
This value represents an HTTP header name or a header
name/value pair. If the value contains a ``:`` (colon), it
will be considered a name/value pair
(e.g. ``User-Agent:Mozilla/.*`` or ``Host:localhost``). The
value portion should be a regular expression. If the value
does not contain a colon, the entire value will be
considered to be the header name
(e.g. ``If-Modified-Since``). If the value evaluates to a
header name only without a value, the header specified by
the name must be present in the request for this predicate
to be true. If the value evaluates to a header name/value
pair, the header specified by the name must be present in
the request *and* the regular expression specified as the
value must match the header value. Whether or not the value
represents a header name or a header name/value pair, the
case of the header name is not significant.
path_info
This value represents a regular expression pattern that will
be tested against the ``PATH_INFO`` WSGI environment
variable. If the regex matches, this predicate will be
``True``.
physical_path
If specified, this value should be a string or a tuple representing
the :term:`physical path` of the context found via traversal for this
predicate to match as true. For example: ``physical_path='/'`` or
``physical_path='/a/b/c'`` or ``physical_path=('', 'a', 'b', 'c')``.
This is not a path prefix match or a regex, it's a whole-path match.
It's useful when you want to always potentially show a view when some
object is traversed to, but you can't be sure about what kind of
object it will be, so you can't use the ``context`` predicate. The
individual path elements in between slash characters or in tuple
elements should be the Unicode representation of the name of the
resource and should not be encoded in any way.
.. versionadded:: 1.4a3
effective_principals
If specified, this value should be a :term:`principal` identifier or
a sequence of principal identifiers. If the
:attr:`pyramid.request.Request.effective_principals` property
indicates that every principal named in the argument list is present
in the current request, this predicate will return True; otherwise it
will return False. For example:
``effective_principals=pyramid.security.Authenticated`` or
``effective_principals=('fred', 'group:admins')``.
.. versionadded:: 1.4a4
custom_predicates
.. deprecated:: 1.5
This value should be a sequence of references to custom
predicate callables. Use custom predicates when no set of
predefined predicates do what you need. Custom predicates
can be combined with predefined predicates as necessary.
Each custom predicate callable should accept two arguments:
``context`` and ``request`` and should return either
``True`` or ``False`` after doing arbitrary evaluation of
the context and/or the request. The ``predicates`` argument
to this method and the ability to register third-party view
predicates via
:meth:`pyramid.config.Configurator.add_view_predicate`
obsoletes this argument, but it is kept around for backwards
compatibility.
view_options
Pass a key/value pair here to use a third-party predicate or set a
value for a view deriver. See
:meth:`pyramid.config.Configurator.add_view_predicate` and
:meth:`pyramid.config.Configurator.add_view_deriver`. See
:ref:`view_and_route_predicates` for more information about
third-party predicates and :ref:`view_derivers` for information
about view derivers.
.. versionadded: 1.4a1
.. versionchanged: 1.7
Support setting view deriver options. Previously, only custom
view predicate values could be supplied.
.. versionchanged:: 2.0
Removed support for the ``check_csrf`` predicate.
"""
if custom_predicates:
warnings.warn(
(
'The "custom_predicates" argument to '
'Configurator.add_view is deprecated as of Pyramid 1.5. '
'Use "config.add_view_predicate" and use the registered '
'view predicate as a predicate argument to add_view '
'instead. See "Adding A Third Party View, Route, or '
'Subscriber Predicate" in the "Hooks" chapter of the '
'documentation for more information.'
),
DeprecationWarning,
stacklevel=4,
)
if accept is not None:
if is_nonstr_iter(accept):
raise ConfigurationError(
'A list is not supported in the "accept" view predicate.'
)
accept = normalize_accept_offer(accept)
view = self.maybe_dotted(view)
context = self.maybe_dotted(context)
for_ = self.maybe_dotted(for_)
containment = self.maybe_dotted(containment)
mapper = self.maybe_dotted(mapper)
if is_nonstr_iter(decorator):
decorator = combine_decorators(*map(self.maybe_dotted, decorator))
else:
decorator = self.maybe_dotted(decorator)
if not view:
if renderer:
def view(context, request):
return {}
else:
raise ConfigurationError(
'"view" was not specified and no "renderer" specified'
)
if request_type is not None:
request_type = self.maybe_dotted(request_type)
if not IInterface.providedBy(request_type):
raise ConfigurationError(
'request_type must be an interface, not %s' % request_type
)
if context is None:
context = for_
isexc = isexception(context)
if exception_only and not isexc:
raise ConfigurationError(
'view "context" must be an exception type when '
'"exception_only" is True'
)
r_context = context
if r_context is None:
r_context = Interface
if not IInterface.providedBy(r_context):
r_context = implementedBy(r_context)
if isinstance(renderer, str):
renderer = renderers.RendererHelper(
name=renderer, package=self.package, registry=self.registry
)
introspectables = []
ovals = view_options.copy()
ovals.update(
dict(
xhr=xhr,
request_method=request_method,
path_info=path_info,
request_param=request_param,
header=header,
accept=accept,
containment=containment,
request_type=request_type,
match_param=match_param,
custom=predvalseq(custom_predicates),
)
)
def discrim_func():
# We need to defer the discriminator until we know what the phash
# is. It can't be computed any sooner because thirdparty
# predicates/view derivers may not yet exist when add_view is
# called.
predlist = self.get_predlist('view')
valid_predicates = predlist.names()
pvals = {}
dvals = {}
for (k, v) in ovals.items():
if k in valid_predicates:
pvals[k] = v
else:
dvals[k] = v
self._check_view_options(**dvals)
order, preds, phash = predlist.make(self, **pvals)
view_intr.update(
{'phash': phash, 'order': order, 'predicates': preds}
)
return ('view', context, name, route_name, phash)
discriminator = Deferred(discrim_func)
if inspect.isclass(view) and attr:
view_desc = 'method %r of %s' % (
attr,
self.object_description(view),
)
else:
view_desc = self.object_description(view)
tmpl_intr = None
view_intr = self.introspectable(
'views', discriminator, view_desc, 'view'
)
view_intr.update(
dict(
name=name,
context=context,
exception_only=exception_only,
containment=containment,
request_param=request_param,
request_methods=request_method,
route_name=route_name,
attr=attr,
xhr=xhr,
accept=accept,
header=header,
path_info=path_info,
match_param=match_param,
http_cache=http_cache,
require_csrf=require_csrf,
callable=view,
mapper=mapper,
decorator=decorator,
)
)
view_intr.update(view_options)
introspectables.append(view_intr)
def register(permission=permission, renderer=renderer):
request_iface = IRequest
if route_name is not None:
request_iface = self.registry.queryUtility(
IRouteRequest, name=route_name
)
if request_iface is None:
# route configuration should have already happened in
# phase 2
raise ConfigurationError(
'No route named %s found for view registration'
% route_name
)
if renderer is None:
# use default renderer if one exists (reg'd in phase 1)
if self.registry.queryUtility(IRendererFactory) is not None:
renderer = renderers.RendererHelper(
name=None, package=self.package, registry=self.registry
)
renderer_type = getattr(renderer, 'type', None)
intrspc = self.introspector
if (
renderer_type is not None
and tmpl_intr is not None
and intrspc is not None
and intrspc.get('renderer factories', renderer_type)
is not None
):
# allow failure of registered template factories to be deferred
# until view execution, like other bad renderer factories; if
# we tried to relate this to an existing renderer factory
# without checking if the factory actually existed, we'd end
# up with a KeyError at startup time, which is inconsistent
# with how other bad renderer registrations behave (they throw
# a ValueError at view execution time)
tmpl_intr.relate('renderer factories', renderer.type)
# make a new view separately for normal and exception paths
if not exception_only:
derived_view = derive_view(False, renderer)
register_view(IViewClassifier, request_iface, derived_view)
if isexc:
derived_exc_view = derive_view(True, renderer)
register_view(
IExceptionViewClassifier, request_iface, derived_exc_view
)
if exception_only:
derived_view = derived_exc_view
# if there are two derived views, combine them into one for
# introspection purposes
if not exception_only and isexc:
derived_view = runtime_exc_view(derived_view, derived_exc_view)
derived_view.__discriminator__ = lambda *arg: discriminator
# __discriminator__ is used by superdynamic systems
# that require it for introspection after manual view lookup;
# see also MultiView.__discriminator__
view_intr['derived_callable'] = derived_view
self.registry._clear_view_lookup_cache()
def derive_view(isexc_only, renderer):
# added by discrim_func above during conflict resolving
preds = view_intr['predicates']