Metadata-Version: 1.1
Name: pyramid_controllers
Version: 0.3.5
Summary: A pyramid plugin that provides de-centralized hierarchical object dispatch.
Home-page: http://github.com/cadithealth/pyramid_controllers
Author: Philip J Grabner, Cadit Health Inc
Author-email: oss@cadit.com
License: MIT (http://opensource.org/licenses/MIT)
Description: pyramid_controllers
        ===================
        
        The ``pyramid_controllers`` package is a pyramid plugin that provides
        de-centralized hierarchical object dispatch, similar to how the
        standard TurboGears request dispatch works.
        
        IMPORTANT: in all of the examples below, simple strings are used as
        responses. There is nothing in pyramid_controllers that forbids the
        use of, or even makes it difficult to use, templating engines. In
        fact, this is encouraged but for simplicity has been omitted here.
        
        Installation
        ------------
        
        You can manually install it by running ``pip install
        pyramid_controllers``. However, a better approach is to use standard
        python distribution utilities, and add pyramid_controllers as a
        dependency in your project's `install_requires` parameter in your
        ``setup.py``. Then run a ``python setup.py develop``.
        
        Usage
        -----
        
        First, enable the package either in your INI file via:
        
        ```
        pyramid.includes = pyramid_controllers
        ```
        
        or in code in your package's application initialization via:
        
        ``` python
        def main(global_config, **settings):
          # ...
          config.include('pyramid_controllers')
          # ...
        ```
        
        Now that your pyramid application has access to the plugin, anchor the
        root controller to a URL entrypoint via the
        ``config.add_controller()`` method. Note that unlike many of the other
        controller approaches, a pyramid_controller route takes control of all
        URLs that are prefixed with the specified entrypoint. For example, the
        following:
        
        ``` python
        def main(global_config, **settings):
          # ...
          config.include('pyramid_controllers')
          # ...
          config.add_controller('rootController', '/root', '.controllers.RootController')
          # ...
        ```
        
        will allow the class ``.controllers.RootController`` to handle any request
        for the URL ``/root`` or URLs that start with ``/root/...``.
        
        Concept
        -------
        
        The basic gist of pyramid_controllers is that for any incoming URL, it
        will be split into components based on forwarded slashes ("/") and
        sequentially lookup the controller in the series while applying name
        lookups, defaulting, access control, and generic request manipulation.
        
        For example, assuming that ``RootController`` is anchored at "/", then
        the following code will handle a request for ``/how/are/you`` by responding
        with the "A-OK!" response.
        
        ``` python
        from pyramid_controllers import Controller, expose
        
        # note: for simplicity, these classes are defined in order of semantic use.
        #       for this to actually work, the controllers would need to be defined
        #       before they are invoked, of course.
        
        class RootController(Controller):
          how = HowController()
        
        class HowController(Controller):
          are = AreController()
        
        class AreController(Controller):
          @expose
          def you(self, request):
            return 'A-OK!'
        ```
        
        Here, the initial request is received by ``RootController``. A lookup
        of the "how" attribute finds that it is associated with another
        controller, so the request is dispatched to that object. The same
        thing happens when the ``HowController`` receives the request, which
        in turn dispatches it to the ``AreController``. When the framework
        does a lookup of the "you" attribute, it finds that it is a method. To
        control which methods are invocable via a URL, you must define the
        method to be exposed to the framework via the ``@expose`` decorator.
        
        At this point the framework hands the request to the object's method for
        handling, providing the active ``request`` object as the first parameter,
        in standard pyramid fashion.
        
        TODO: add documentation about the various supported response and
        exception types.
        
        Controllers
        -----------
        
        There exist two classes that can be subclassed to produce controller
        classes:
        
        * **pyramid_controllers.Controller**: this class is the base class
          of all controllers, and does not provide much functionality other
          than allowing the framework to know that a class is intended to
          handle requests in a pyramid_controllers approach.
        
        * **pyramid_controllers.RestController**: this class routes the
          various RESTful verbs to controller methods by the same name
          (note that the method names are lower-cased).
        
        Here is an example of the latter, which will accept any of the
        standard HTTP verbs (GET, PUT, POST, DELETE) to the URL "/hello" and
        will emit a response that simply reflects the method used (with a
        little poetic licence thrown in):
        
        ``` python
        from pyramid_controllers import Controller, RestController
        
        class RootController(Controller):
          hello = ReflectController()
        
        class ReflectController(RestController):
          @expose
          def get(self, request):
            return 'I am *not* a dog, go GET it yourself!'
          @expose
          def put(self, request):
            return 'Apparently you golf. PUTting is just part of the game.'
          @expose
          def post(self, request):
            return 'People use email today, silly. Stop using the POST!'
          @expose
          def delete(self, request):
            return 'Hey! This is not the CIA, you cannot just DELETE me!'
        ```
        
        Decorators
        ----------
        
        There are several decorators provided by the pyramid_controllers
        package that influence how a request is handled, as follows:
        
        * **@expose**: the most common decorator, it simply declares that the
          decorated method is intended to handle incoming requests, and is
          therefore "exposed" to the public. Note that although it is exposed,
          access control restrictions may restrict who can actually access it.
        
        * **@index**: declares that the decorated method is the method that
          will handle the request if no further components in the URL path
          exist. Think of this as the ``index.html`` in an htdocs directory.
        
        * **@default**: if the standard component lookup strategy fails to
          match either a sub-controller or method to handle a request, then
          the framework searches for a method that has been decorated as a
          ``@default`` or ``@lookup`` method (``@lookup`` decorators take
          precedence). The default method is expected to behave identically to
          an "exposed" method.
        
        * **@lookup**: similar to the ``@default`` decorator, the ``@lookup``
          decorator is invoked when the framework could not find another
          method or sub-controller to handle the request. The @lookup method,
          unlike the @default method, is **not** expected to handle the actual
          request, but instead to return a new controller with which the
          framework will continue the hierarchical request handling. See below
          for details on what parameters are passed and what is expected to be
          returned.
        
        * **@fiddle**: a method declared as a "fiddler" will be called before
          any other method in the given controller and is expected to do
          nothing more than alter the request in some way (such as add
          additional attributes) or throw an exception. A fiddler method must
          **NOT** be expected to actually respond to a request via standard
          methods.
        
        Complex Example
        ---------------
        
        ``` python
        
        from pyramid.httpexceptions import HTTPForbidden, HTTPNotFound
        
        # import the controller base classes
        from pyramid_controllers import Controller, RestController
        
        # import the decorators
        from pyramid_controllers import expose, index, lookup, default, fiddle
        
        class RootController(Controller):
          public = PublicController()
          admin  = AdminController()
          member = MemberDispatchController()
        
        class PublicController(Controller):
          login = AuthController()
          @expose
          def about(self, request):
            return 'We are a snazy company!'
        
        class AuthController(RestController):
          @expose
          def get(self, request):
            return '<html><form><input name="u"/><input name="p"/></form></html>'
          @expose
          def post(self, request):
            # todo: perform authentication...
        
        class AdminController(Controller):
          @fiddle
          def checkAuth(self, request):
            if userHasAdminAccess(request): return
            raise HTTPForbidden()
          @index
          def index(self, request):
            return 'View the list of <a href="users">active users</a>.'
          @expose
          def users(self, request):
            return '<ul><li>you</li></ul>'
        
        class MemberDispatchController(Controller):
          @fiddle
          def checkAuth(self, request):
            if userHasMemberAccess(request): return
            raise HTTPForbidden()
          @lookup
          def _lookup(self, username, *rem):
            user = findUserByUsername(username)
            if not user:
              raise HTTPNotFound()
            return (MemberController(user), rem)
        
        class MemberController(Controller):
          def __init__(self, user):
            self.user = user
          @index
          def index(self, request):
            return 'Hi, my name is ' + self.user.name
          @expose
          def age(self, request):
            return 'I am %d years old.' % (self.user.age,)
          @default
          def _default(self, request, attribute, *rem):
            return 'My "%s" is "%r".' % (attribute, getattr(self.user, attribute))
        ```
        
Keywords: web wsgi pyramid bfg pylons turbogears controller handler object-dispatch request-dispatch
Platform: UNKNOWN
Classifier: Intended Audience :: Developers
Classifier: Programming Language :: Python
Classifier: Framework :: Pyramid
Classifier: Environment :: Console
Classifier: Environment :: Web Environment
Classifier: Operating System :: OS Independent
Classifier: Topic :: Internet
Classifier: Topic :: Software Development
Classifier: Topic :: Internet :: WWW/HTTP
Classifier: Topic :: Internet :: WWW/HTTP :: WSGI
Classifier: Topic :: Software Development :: Libraries :: Application Frameworks
Classifier: Natural Language :: English
Classifier: License :: OSI Approved :: MIT License
Classifier: License :: Public Domain
