.. _framework-integration:
Routing
=======
The package comes with support for routing URLs to skin objects. This
works with resources -- images, stylesheets and other static files --
and templates (these are rendered into a response).
For BFG to render the skin objects, we must register views such that
the router can publish them. The benefit is that we can reuse the
``view`` directive and even protect the views with permissions.
Adding views
############
To expose the contents of a skin directory as *views*, we can insert a
``view`` registration directive into the ``skins`` directive::
.. -> configuration
>>> from zope.configuration.xmlconfig import string
>>> _ = string("""
...
...
...
... %(configuration)s
... """.strip() % locals())
>>> from repoze.bfg.view import render_view
>>> from repoze.bfg.testing import DummyRequest
>>> render_view('Hello world!', DummyRequest(), name="") is None
True
>>> print render_view('Hello world!', DummyRequest(), name="index")
Hello world!
The ``view`` directive has no required attributes, but all the
attributes which are applicable for the standalone directive [#]_ are
available, except ``name`` which is defined by the component and
``view`` which is given by the skin object.
.. note:: Views are registered using the component name. However, the directory separator character ("/") is replaced by an underscore (e.g. "images/logo.png" becomes "images_logo.png"). This is a technical detail if you use the built-in routing functionality.
When wrapped inside ``skins``, an option ``index`` is available to
allow registering default index views (e.g. ``index.pt``)::
.. -> configuration
>>> _ = string("""
...
...
...
... %(configuration)s
... """.strip() % locals())
>>> print render_view('Hello world!', DummyRequest(), name="")
Hello world!
When an index name is set, a view is registered for the directory
path, mapped to the index object in the directory.
.. [#] See the `repoze.bfg view request type documentation `_ for more information on request types.
Route factory
#############
We can configure a route to serve up skins registered as views under
some path -- ``subpath`` -- using the provided routes traverser
factory::
.. -> configuration
>>> _ = string("""
...
...
... %(configuration)s
... """.strip() % locals())
>>> from zope.component import getSiteManager
>>> registry = getSiteManager()
>>> from repoze.bfg.router import Router
>>> router = Router(registry)
>>> environ = {
... 'wsgi.url_scheme':'http',
... 'SERVER_NAME':'localhost',
... 'SERVER_PORT':'8080',
... 'REQUEST_METHOD':'GET',
... 'PATH_INFO':'/static/images/logo.png',
... }
>>> def start_response(*args): print args
>>> from repoze.bfg.interfaces import IRoutesMapper
>>> from zope.component import getUtility
>>> router.root_factory = getUtility(IRoutesMapper)
>>> app_iter = router(environ, start_response)
('200 OK', [('Content-Length', '2833'), ('content-type', 'image/png')])
This traverser will convert ``subpath`` into a view name which then
prompts the BFG router to publish the skin object (by calling it).