Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/twisted/web/_element.py

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+# -*- test-case-name: twisted.web.test.test_template -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+from __future__ import division, absolute_import
+
+from zope.interface import implementer
+
+from twisted.web.iweb import IRenderable
+from twisted.web.error import MissingRenderMethod, UnexposedMethodError
+from twisted.web.error import MissingTemplateLoader
+
+
+class Expose(object):
+    """
+    Helper for exposing methods for various uses using a simple decorator-style
+    callable.
+
+    Instances of this class can be called with one or more functions as
+    positional arguments.  The names of these functions will be added to a list
+    on the class object of which they are methods.
+
+    @ivar attributeName: The attribute with which exposed methods will be
+    tracked.
+    """
+    def __init__(self, doc=None):
+        self.doc = doc
+
+
+    def __call__(self, *funcObjs):
+        """
+        Add one or more functions to the set of exposed functions.
+
+        This is a way to declare something about a class definition, similar to
+        L{zope.interface.declarations.implementer}.  Use it like this::
+
+            magic = Expose('perform extra magic')
+            class Foo(Bar):
+                def twiddle(self, x, y):
+                    ...
+                def frob(self, a, b):
+                    ...
+                magic(twiddle, frob)
+
+        Later you can query the object::
+
+            aFoo = Foo()
+            magic.get(aFoo, 'twiddle')(x=1, y=2)
+
+        The call to C{get} will fail if the name it is given has not been
+        exposed using C{magic}.
+
+        @param funcObjs: One or more function objects which will be exposed to
+        the client.
+
+        @return: The first of C{funcObjs}.
+        """
+        if not funcObjs:
+            raise TypeError("expose() takes at least 1 argument (0 given)")
+        for fObj in funcObjs:
+            fObj.exposedThrough = getattr(fObj, 'exposedThrough', [])
+            fObj.exposedThrough.append(self)
+        return funcObjs[0]
+
+
+    _nodefault = object()
+    def get(self, instance, methodName, default=_nodefault):
+        """
+        Retrieve an exposed method with the given name from the given instance.
+
+        @raise UnexposedMethodError: Raised if C{default} is not specified and
+        there is no exposed method with the given name.
+
+        @return: A callable object for the named method assigned to the given
+        instance.
+        """
+        method = getattr(instance, methodName, None)
+        exposedThrough = getattr(method, 'exposedThrough', [])
+        if self not in exposedThrough:
+            if default is self._nodefault:
+                raise UnexposedMethodError(self, methodName)
+            return default
+        return method
+
+
+    @classmethod
+    def _withDocumentation(cls, thunk):
+        """
+        Slight hack to make users of this class appear to have a docstring to
+        documentation generators, by defining them with a decorator.  (This hack
+        should be removed when epydoc can be convinced to use some other method
+        for documenting.)
+        """
+        return cls(thunk.__doc__)
+
+
+# Avoid exposing the ugly, private classmethod name in the docs.  Luckily this
+# namespace is private already so this doesn't leak further.
+exposer = Expose._withDocumentation
+
+@exposer
+def renderer():
+    """
+    Decorate with L{renderer} to use methods as template render directives.
+
+    For example::
+
+        class Foo(Element):
+            @renderer
+            def twiddle(self, request, tag):
+                return tag('Hello, world.')
+
+        <div xmlns:t="http://twistedmatrix.com/ns/twisted.web.template/0.1">
+            <span t:render="twiddle" />
+        </div>
+
+    Will result in this final output::
+
+        <div>
+            <span>Hello, world.</span>
+        </div>
+    """
+
+
+
+@implementer(IRenderable)
+class Element(object):
+    """
+    Base for classes which can render part of a page.
+
+    An Element is a renderer that can be embedded in a stan document and can
+    hook its template (from the loader) up to render methods.
+
+    An Element might be used to encapsulate the rendering of a complex piece of
+    data which is to be displayed in multiple different contexts.  The Element
+    allows the rendering logic to be easily re-used in different ways.
+
+    Element returns render methods which are registered using
+    L{twisted.web._element.renderer}.  For example::
+
+        class Menu(Element):
+            @renderer
+            def items(self, request, tag):
+                ....
+
+    Render methods are invoked with two arguments: first, the
+    L{twisted.web.http.Request} being served and second, the tag object which
+    "invoked" the render method.
+
+    @type loader: L{ITemplateLoader} provider
+    @ivar loader: The factory which will be used to load documents to
+        return from C{render}.
+    """
+    loader = None
+
+    def __init__(self, loader=None):
+        if loader is not None:
+            self.loader = loader
+
+
+    def lookupRenderMethod(self, name):
+        """
+        Look up and return the named render method.
+        """
+        method = renderer.get(self, name, None)
+        if method is None:
+            raise MissingRenderMethod(self, name)
+        return method
+
+
+    def render(self, request):
+        """
+        Implement L{IRenderable} to allow one L{Element} to be embedded in
+        another's template or rendering output.
+
+        (This will simply load the template from the C{loader}; when used in a
+        template, the flattening engine will keep track of this object
+        separately as the object to lookup renderers on and call
+        L{Element.renderer} to look them up.  The resulting object from this
+        method is not directly associated with this L{Element}.)
+        """
+        loader = self.loader
+        if loader is None:
+            raise MissingTemplateLoader(self)
+        return loader.load()