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Source code for pyramid.view

import mimetypes

# See http://bugs.python.org/issue5853 which is a recursion bug
# that seems to effect Python 2.6, Python 2.6.1, and 2.6.2 (a fix
# has been applied on the Python 2 trunk).  This workaround should
# really be in Paste if anywhere, but it's easiest to just do it
# here and get it over with to avoid needing to deal with any
# fallout.

if hasattr(mimetypes, 'init'):
    mimetypes.init()

import venusian

from zope.interface import providedBy
from zope.deprecation import deprecated

from pyramid.interfaces import IRoutesMapper
from pyramid.interfaces import IView
from pyramid.interfaces import IViewClassifier

from pyramid.httpexceptions import HTTPFound
from pyramid.renderers import RendererHelper
from pyramid.static import static_view
from pyramid.threadlocal import get_current_registry

# Nast BW compat hack: dont yet deprecate this (ever?)
[docs]class static(static_view): # only subclass for purposes of autodoc __doc__ = static_view.__doc__
_marker = object()
[docs]def render_view_to_response(context, request, name='', secure=True): """ Call the :term:`view callable` configured with a :term:`view configuration` that matches the :term:`view name` ``name`` registered against the specified ``context`` and ``request`` and return a :term:`response` object. This function will return ``None`` if a corresponding :term:`view callable` cannot be found (when no :term:`view configuration` matches the combination of ``name`` / ``context`` / and ``request``). If `secure`` is ``True``, and the :term:`view callable` found is protected by a permission, the permission will be checked before calling the view function. If the permission check disallows view execution (based on the current :term:`authorization policy`), a :exc:`pyramid.exceptions.Forbidden` exception will be raised. The exception's ``args`` attribute explains why the view access was disallowed. If ``secure`` is ``False``, no permission checking is done.""" provides = [IViewClassifier] + map(providedBy, (request, context)) try: reg = request.registry except AttributeError: reg = get_current_registry() view = reg.adapters.lookup(provides, IView, name=name) if view is None: return None if not secure: # the view will have a __call_permissive__ attribute if it's # secured; otherwise it won't. view = getattr(view, '__call_permissive__', view) # if this view is secured, it will raise a Forbidden # appropriately if the executing user does not have the proper # permission return view(context, request)
[docs]def render_view_to_iterable(context, request, name='', secure=True): """ Call the :term:`view callable` configured with a :term:`view configuration` that matches the :term:`view name` ``name`` registered against the specified ``context`` and ``request`` and return an iterable object which represents the body of a response. This function will return ``None`` if a corresponding :term:`view callable` cannot be found (when no :term:`view configuration` matches the combination of ``name`` / ``context`` / and ``request``). Additionally, this function will raise a :exc:`ValueError` if a view function is found and called but the view function's result does not have an ``app_iter`` attribute. You can usually get the string representation of the return value of this function by calling ``''.join(iterable)``, or just use :func:`pyramid.view.render_view` instead. If ``secure`` is ``True``, and the view is protected by a permission, the permission will be checked before the view function is invoked. If the permission check disallows view execution (based on the current :term:`authentication policy`), a :exc:`pyramid.exceptions.Forbidden` exception will be raised; its ``args`` attribute explains why the view access was disallowed. If ``secure`` is ``False``, no permission checking is done.""" response = render_view_to_response(context, request, name, secure) if response is None: return None return response.app_iter
[docs]def render_view(context, request, name='', secure=True): """ Call the :term:`view callable` configured with a :term:`view configuration` that matches the :term:`view name` ``name`` registered against the specified ``context`` and ``request`` and unwind the view response's ``app_iter`` (see :ref:`the_response`) into a single string. This function will return ``None`` if a corresponding :term:`view callable` cannot be found (when no :term:`view configuration` matches the combination of ``name`` / ``context`` / and ``request``). Additionally, this function will raise a :exc:`ValueError` if a view function is found and called but the view function's result does not have an ``app_iter`` attribute. This function will return ``None`` if a corresponding view cannot be found. If ``secure`` is ``True``, and the view is protected by a permission, the permission will be checked before the view is invoked. If the permission check disallows view execution (based on the current :term:`authorization policy`), a :exc:`pyramid.exceptions.Forbidden` exception will be raised; its ``args`` attribute explains why the view access was disallowed. If ``secure`` is ``False``, no permission checking is done.""" iterable = render_view_to_iterable(context, request, name, secure) if iterable is None: return None return ''.join(iterable)
[docs]def is_response(ob): """ Return ``True`` if ``ob`` implements the interface implied by :ref:`the_response`. ``False`` if not. .. note:: This isn't a true interface or subclass check. Instead, it's a duck-typing check, as response objects are not obligated to be of a particular class or provide any particular Zope interface.""" # response objects aren't obligated to implement a Zope interface, # so we do it the hard way if ( hasattr(ob, 'app_iter') and hasattr(ob, 'headerlist') and hasattr(ob, 'status') ): return True return False
[docs]class view_config(object): """ A function, class or method :term:`decorator` which allows a developer to create view registrations nearer to a :term:`view callable` definition than use :term:`imperative configuration` to do the same. For example, this code in a module ``views.py``:: from resources import MyResource @view_config(name='my_view', context=MyResource, permission='read', route_name='site1') def my_view(context, request): return 'OK' Might replace the following call to the :meth:`pyramid.config.Configurator.add_view` method:: import views from resources import MyResource config.add_view(views.my_view, context=MyResource, name='my_view', permission='read', 'route_name='site1') .. note: :class:`pyramid.view.view_config` is also importable, for backwards compatibility purposes, as the name :class:`pyramid.view.bfg_view`. The following arguments are supported as arguments to :class:`pyramid.view.view_config`: ``context``, ``permission``, ``name``, ``request_type``, ``route_name``, ``request_method``, ``request_param``, ``containment``, ``xhr``, ``accept``, ``header``, ``path_info``, ``custom_predicates``, ``decorator``, and ``mapper``. The meanings of these arguments are the same as the arguments passed to :meth:`pyramid.config.Configurator.add_view`. See :ref:`mapping_views_using_a_decorator_section` for details about using :class:`view_config`. """ venusian = venusian # for testing injection def __init__(self, name='', request_type=None, for_=None, permission=None, route_name=None, request_method=None, request_param=None, containment=None, attr=None, renderer=None, wrapper=None, xhr=False, accept=None, header=None, path_info=None, custom_predicates=(), context=None, decorator=None, mapper=None): self.name = name self.request_type = request_type self.context = context or for_ self.permission = permission self.route_name = route_name self.request_method = request_method self.request_param = request_param self.containment = containment self.attr = attr self.renderer = renderer self.wrapper = wrapper self.xhr = xhr self.accept = accept self.header = header self.path_info = path_info self.custom_predicates = custom_predicates self.decorator = decorator self.mapper = mapper def __call__(self, wrapped): settings = self.__dict__.copy() def callback(context, name, ob): renderer = settings.get('renderer') if isinstance(renderer, basestring): renderer = RendererHelper(name=renderer, package=info.module, registry=context.config.registry) settings['renderer'] = renderer context.config.add_view(view=ob, **settings) info = self.venusian.attach(wrapped, callback, category='pyramid') if info.scope == 'class': # if the decorator was attached to a method in a class, or # otherwise executed at class scope, we need to set an # 'attr' into the settings if one isn't already in there if settings['attr'] is None: settings['attr'] = wrapped.__name__ settings['_info'] = info.codeinfo return wrapped
bfg_view = view_config # permanent b/c deprecated( 'bfg_view', 'pyramid.view.bfg_view is deprecated as of Pyramid 1.0. Use ' 'pyramid.view.view_config instead (API-compat, simple ' 'rename).') def default_exceptionresponse_view(context, request): if not isinstance(context, Exception): # backwards compat for an exception response view registered via # config.set_notfound_view or config.set_forbidden_view # instead of as a proper exception view context = request.exception or context return context
[docs]class AppendSlashNotFoundViewFactory(object): """ There can only be one :term:`Not Found view` in any :app:`Pyramid` application. Even if you use :func:`pyramid.view.append_slash_notfound_view` as the Not Found view, :app:`Pyramid` still must generate a ``404 Not Found`` response when it cannot redirect to a slash-appended URL; this not found response will be visible to site users. If you don't care what this 404 response looks like, and you only need redirections to slash-appended route URLs, you may use the :func:`pyramid.view.append_slash_notfound_view` object as the Not Found view. However, if you wish to use a *custom* notfound view callable when a URL cannot be redirected to a slash-appended URL, you may wish to use an instance of this class as the Not Found view, supplying a :term:`view callable` to be used as the custom notfound view as the first argument to its constructor. For instance: .. code-block:: python from pyramid.exceptions import NotFound from pyramid.view import AppendSlashNotFoundViewFactory def notfound_view(context, request): return HTTPNotFound('It aint there, stop trying!') custom_append_slash = AppendSlashNotFoundViewFactory(notfound_view) config.add_view(custom_append_slash, context=NotFound) The ``notfound_view`` supplied must adhere to the two-argument view callable calling convention of ``(context, request)`` (``context`` will be the exception object). """ def __init__(self, notfound_view=None): if notfound_view is None: notfound_view = default_exceptionresponse_view self.notfound_view = notfound_view def __call__(self, context, request): if not isinstance(context, Exception): # backwards compat for an append_notslash_view registered via # config.set_notfound_view instead of as a proper exception view context = request.exception path = request.environ.get('PATH_INFO', '/') registry = request.registry mapper = registry.queryUtility(IRoutesMapper) if mapper is not None and not path.endswith('/'): slashpath = path + '/' for route in mapper.get_routes(): if route.match(slashpath) is not None: if request.environ.get('QUERY_STRING'): slashpath += '?' + request.environ['QUERY_STRING'] return HTTPFound(location=slashpath) return self.notfound_view(context, request)
append_slash_notfound_view = AppendSlashNotFoundViewFactory() append_slash_notfound_view.__doc__ = """\ For behavior like Django's ``APPEND_SLASH=True``, use this view as the :term:`Not Found view` in your application. When this view is the Not Found view (indicating that no view was found), and any routes have been defined in the configuration of your application, if the value of the ``PATH_INFO`` WSGI environment variable does not already end in a slash, and if the value of ``PATH_INFO`` *plus* a slash matches any route's path, do an HTTP redirect to the slash-appended PATH_INFO. Note that this will *lose* ``POST`` data information (turning it into a GET), so you shouldn't rely on this to redirect POST requests. Use the :meth:`pyramid.config.Configurator.add_view` method to configure this view as the Not Found view:: from pyramid.exceptions import NotFound from pyramid.view import append_slash_notfound_view config.add_view(append_slash_notfound_view, context=NotFound) See also :ref:`changing_the_notfound_view`. """