Source code for pyramid.registry

import operator

from zope.interface import implementer

from zope.interface.registry import Components

from pyramid.compat import text_

from pyramid.interfaces import (

empty = text_('')

[docs]class Registry(Components, dict): """ A registry object is an :term:`application registry`. It is used by the framework itself to perform mappings of URLs to view callables, as well as servicing other various framework duties. A registry has its own internal API, but this API is rarely used by Pyramid application developers (it's usually only used by developers of the Pyramid framework). But it has a number of attributes that may be useful to application developers within application code, such as ``settings``, which is a dictionary containing application deployment settings. For information about the purpose and usage of the application registry, see :ref:`zca_chapter`. The application registry is usually accessed as ``request.registry`` in application code. """ # for optimization purposes, if no listeners are listening, don't try # to notify them has_listeners = False _settings = None def __nonzero__(self): # defeat bool determination via dict.__len__ return True def registerSubscriptionAdapter(self, *arg, **kw): result = Components.registerSubscriptionAdapter(self, *arg, **kw) self.has_listeners = True return result def registerSelfAdapter(self, required=None, provided=None, name=empty, info=empty, event=True): # registerAdapter analogue which always returns the object itself # when required is matched return self.registerAdapter(lambda x: x, required=required, provided=provided, name=name, info=info, event=event) def queryAdapterOrSelf(self, object, interface, default=None): # queryAdapter analogue which returns the object if it implements # the interface, otherwise it will return an adaptation to the # interface if not interface.providedBy(object): return self.queryAdapter(object, interface, default=default) return object def registerHandler(self, *arg, **kw): result = Components.registerHandler(self, *arg, **kw) self.has_listeners = True return result def notify(self, *events): if self.has_listeners: # iterating over subscribers assures they get executed [ _ for _ in self.subscribers(events, None) ] # backwards compatibility for code that wants to look up a settings # object via ``registry.getUtility(ISettings)`` def _get_settings(self): return self._settings def _set_settings(self, settings): self.registerUtility(settings, ISettings) self._settings = settings settings = property(_get_settings, _set_settings)
@implementer(IIntrospector) class Introspector(object): def __init__(self): self._refs = {} self._categories = {} self._counter = 0 def add(self, intr): category = self._categories.setdefault(intr.category_name, {}) category[intr.discriminator] = intr category[intr.discriminator_hash] = intr intr.order = self._counter self._counter += 1 def get(self, category_name, discriminator, default=None): category = self._categories.setdefault(category_name, {}) intr = category.get(discriminator, default) return intr def get_category(self, category_name, default=None, sort_key=None): if sort_key is None: sort_key = operator.attrgetter('order') category = self._categories.get(category_name) if category is None: return default values = category.values() values = sorted(set(values), key=sort_key) return [ {'introspectable':intr, 'related':self.related(intr)} for intr in values ] def categorized(self, sort_key=None): L = [] for category_name in self.categories(): L.append((category_name, self.get_category(category_name, sort_key=sort_key))) return L def categories(self): return sorted(self._categories.keys()) def remove(self, category_name, discriminator): intr = self.get(category_name, discriminator) if intr is None: return L = self._refs.pop(intr, []) for d in L: L2 = self._refs[d] L2.remove(intr) category = self._categories[intr.category_name] del category[intr.discriminator] del category[intr.discriminator_hash] def _get_intrs_by_pairs(self, pairs): introspectables = [] for pair in pairs: category_name, discriminator = pair intr = self._categories.get(category_name, {}).get(discriminator) if intr is None: raise KeyError((category_name, discriminator)) introspectables.append(intr) return introspectables def relate(self, *pairs): introspectables = self._get_intrs_by_pairs(pairs) relatable = ((x,y) for x in introspectables for y in introspectables) for x, y in relatable: L = self._refs.setdefault(x, []) if x is not y and y not in L: L.append(y) def unrelate(self, *pairs): introspectables = self._get_intrs_by_pairs(pairs) relatable = ((x,y) for x in introspectables for y in introspectables) for x, y in relatable: L = self._refs.get(x, []) if y in L: L.remove(y) def related(self, intr): category_name, discriminator = intr.category_name, intr.discriminator intr = self._categories.get(category_name, {}).get(discriminator) if intr is None: raise KeyError((category_name, discriminator)) return self._refs.get(intr, []) @implementer(IIntrospectable)
[docs]class Introspectable(dict): order = 0 # mutated by introspector.add action_info = None # mutated by self.register def __init__(self, category_name, discriminator, title, type_name): self.category_name = category_name self.discriminator = discriminator self.title = title self.type_name = type_name self._relations = [] def relate(self, category_name, discriminator): self._relations.append((True, category_name, discriminator)) def unrelate(self, category_name, discriminator): self._relations.append((False, category_name, discriminator)) def _assert_resolved(self): assert undefer(self.discriminator) is self.discriminator @property def discriminator_hash(self): self._assert_resolved() return hash(self.discriminator) def __hash__(self): self._assert_resolved() return hash((self.category_name,) + (self.discriminator,)) def __repr__(self): self._assert_resolved() return '<%s category %r, discriminator %r>' % (self.__class__.__name__, self.category_name, self.discriminator) def __nonzero__(self): return True __bool__ = __nonzero__ # py3 def register(self, introspector, action_info): self.discriminator = undefer(self.discriminator) self.action_info = action_info introspector.add(self) for relate, category_name, discriminator in self._relations: discriminator = undefer(discriminator) if relate: method = introspector.relate else: method = introspector.unrelate method( (self.category_name, self.discriminator), (category_name, discriminator) )
[docs]class Deferred(object): """ Can be used by a third-party configuration extender to wrap a :term:`discriminator` during configuration if an immediately hashable discriminator cannot be computed because it relies on unresolved values. The function should accept no arguments and should return a hashable discriminator.""" def __init__(self, func): self.func = func def resolve(self): return self.func()
[docs]def undefer(v): """ Function which accepts an object and returns it unless it is a :class:`pyramid.registry.Deferred` instance. If it is an instance of that class, its ``resolve`` method is called, and the result of the method is returned.""" if isinstance(v, Deferred): v = v.resolve() return v
[docs]class predvalseq(tuple): """ A subtype of tuple used to represent a sequence of predicate values """ pass
global_registry = Registry('global')