Moved README docs into docs.

1 files changed, 12 insertions, 435 deletions

diff --git a/README.txt b/README.txt
index 17a183576..f71e64cb5 100644
--- a/README.txt
+++ b/README.txt
@@ -7,444 +7,21 @@ uses Zope libraries to do much of its work.  However, it is less
 ambitious and less featureful than any released version of Zope's
 publisher.
 
-``repoze.bfg`` uses the WSGI protocol to handle requests and
-responses, and integrates Zope, Paste, and WebOb libraries to form the
-basis for a simple web object publishing framework.
+Installation
+------------
 
-Graph Traversal
----------------
+Install using setuptools, e.g. (within a virtualenv)::
 
-In many popular web frameworks, a "URL dispatcher" is used to
-associate a particular URL with a bit of code (known somewhat
-ambiguously as a "controller" or "view" depending upon the particular
-vocabulary religion to which you subscribe).  These systems allow the
-developer to create "urlconfs" or "routes" to controller/view Python
-code using pattern matching against URL components.  Examples:
-`Django's URL dispatcher
-<http://www.djangoproject.com/documentation/url_dispatch/>`_ and the
-`Routes URL mapping system <http://routes.groovie.org/>`_ .
+  $ easy_install -i http://dist.repoze.org/lemonade/dev/simple repoze.bfg
 
-It is however possible to map URLs to code differently, using object
-graph traversal. The venerable Zope and CherryPy web frameworks offer
-graph-traversal-based URL dispatch.  ``repoze.bfg`` also provides
-graph-traversal-based dispatch of URLs to code.  Graph-traversal based
-dispatching is useful if you like the URL to be representative of an
-arbitrary hierarchy of potentially heterogeneous items.
+Further Documentation
+---------------------
 
-Non-graph traversal based URL dispatch can easily handle URLs such as
-``http://example.com/members/Chris``, where it's assumed that each
-item "below" ``members`` in the URL represents a member in the system.
-You just match everything "below" ``members`` to a particular view.
-They are not very good, however, at inferring the difference between
-sets of URLs such as ``http://example.com/members/Chris/document`` vs.
-``http://example.com/members/Chris/stuff/page`` wherein you'd like the
-``document`` in the first URL to represent, e.g. a PDF document, and
-``/stuff/page`` in the second to represent, e.g. an OpenOffice
-document in a "stuff" folder.  It takes more pattern matching
-assertions to be able to make URLs like these work in URL-dispatch
-based systems, and some assertions just aren't possible.  For example,
-URL-dispatch based systems don't deal very well with URLs that
-represent arbitrary-depth hierarchies.
+See the ``docs`` directory of the repoze.bfg distribution package
+(also available via http://svn.repoze.org/repoze.bfg/trunk/docs).
 
-Graph traversal works well if you need to divine meaning out of these
-types of "ambiguous" URLs and URLs that represent arbitrary-depth
-hierarchies.  Each URL segment represents a single traversal through
-an edge of the graph.  So a URL like ``http://example.com/a/b/c`` can
-be thought of as a graph traversal on the example.com site through the
-edges "a", "b", and "c".
+Reporting Bugs / Development Versions
+-------------------------------------
 
-Finally, if you're willing to treat your application models as a graph
-that can be traversed, it also becomes trivial to provide "row-level
-security" (in common relational parlance): you just attach a security
-declaration to each instance in the graph.  This is not as easy in
-frameworks that use URL-based dispatch.
-
-Graph traversal is materially more complex than URL-based dispatch,
-however, if only because it requires the construction and maintenance
-of a graph, and it requires the developer to think about mapping URLs
-to code in terms of traversing the graph.  (How's *that* for
-self-referential! ;-) That said, for developers comfortable with Zope,
-in particular, and comfortable with hierarchical data stores like
-ZODB, mapping a URL to a graph traversal it's a natural way to think
-about creating a web application.
-
-In essence, the choice to use graph traversal vs. URL dispatch is
-largely religious in some sense.  Graph traversal dispatch probably
-just doesn't make any sense when you possess completely "square" data
-stored in a relational database.  However, when you have a
-hierarchical data store, it can provide advantages over using
-URL-based dispatch.
-
-Similarities with Other Frameworks
-----------------------------------
-
-The Django docs state that Django is an "MTV" framework in their `FAQ
-<http://www.djangoproject.com/documentation/faq/>`_.  This also
-happens to be true for ``repoze.bfg``::
-
-  Django appears to be a MVC framework, but you call the Controller
-  the "view", and the View the "template". How come you don’t use the
-  standard names?
-
-  Well, the standard names are debatable.
-
-  In our interpretation of MVC, the "view" describes the data that
-  gets presented to the user. It’s not necessarily how the data looks,
-  but which data is presented. The view describes which data you see,
-  not how you see it. It’s a subtle distinction.
-
-  So, in our case, a "view" is the Python callback function for a
-  particular URL, because that callback function describes which data
-  is presented.
-
-  Furthermore, it’s sensible to separate content from presentation —
-  which is where templates come in. In Django, a "view" describes
-  which data is presented, but a view normally delegates to a
-  template, which describes how the data is presented.
-
-  Where does the "controller" fit in, then? In Django’s case, it’s
-  probably the framework itself: the machinery that sends a request to
-  the appropriate view, according to the Django URL configuration.
-
-  If you’re hungry for acronyms, you might say that Django is a "MTV"
-  framework — that is, "model", "template", and "view." That breakdown
-  makes much more sense.
-
-How ``repoze.bfg`` is Configured
---------------------------------
-
-Users interact with your ``repoze.bfg``-based application via a
-"router", which is itself a WSGI application.  At system startup time,
-the router must be configured with a root object from which all
-traversal will begin.  The root object is a mapping object, such as a
-Python dictionary.  In fact, all items contained in the graph are
-either leaf nodes (these have no __getitem__) or container nodes
-(these do have a __getitem__).
-
-Items contained within the graph are analogous to the concept of
-``model`` objects used by many other frameworks.  They are typically
-instances of classes.  Each containerish instance is willing to return
-a child or raise a KeyError based on a name passed to its __getitem__.
-No leaf-level instance is required to have a __getitem__.
-
-Jargon
-------
-
-The following jargon is used casually in descriptions of
-``repoze.bfg`` operations.
-
-request
-
-  A ``WebOb`` request object.
-
-response
-
-  An object that has three attributes: app_iter (representing an
-  iterable body), headerlist (representing the http headers sent
-  upstream), and status (representing the http status string).  This
-  is the interface defined for ``WebOb`` response objects.
-
-mapply
-
-  code which dynamically ("magically") determines which arguments to
-  pass to a view based on environment and request parameters.
-
-view constructor and view
-
-  A "view constructor" is a callable which returns a view object.  It
-  should accept two values: context and request.
-
-  A "view" is a callable that accepts arbitrary values (mapped into it
-  by "mapply") and which returns a response object.
-
-  A view constructor may *be* a view in a repoze.bfg application
-  (e.g. it may accept "context" and "request" and return a response
-  object directly instead of returning a view object).  This makes it
-  possible to support views as simple functions.
-
-view name
-
-  The "URL name" of a view, e.g "index.html".  If a view is configured
-  without a name, its name is considered to be the empty string (which
-  implies the "default view").
-
-model
-
-  An object representing data in the system.  A model is part of the
-  object graph traversed by the system.  Models are traversed to
-  determine a context.
-
-context
-
-  A model in the system that is the subject of a view.
-
-view registry
-
-  A registry which maps a context and view name to a view constructor
-  and optionally a permission.
-
-template
-
-  A file that is capable of representing some text when rendered.
-
-interface
-
-  An attribute of a model object that determines its type.
-
-security policy
-
-  An object that provides a mechanism to check authorization using
-  authentication data and a permission associated with a model.  It
-  essentially returns "true" if the combination of the authorization
-  information in the model (e.g. an ACL) and the authentication data
-  in the request (e.g. the REMOTE_USER) allow the action implied by
-  the permission associated with the view (e.g. "add").
-
-principal
-
-  A user id or group id.
-
-permission
-
-  A permission is a string token that is associated with a view name
-  and a model type by the developer.  Models are decorated with
-  security declarations (e.g. ACLs), which reference these tokens
-  also.  A security policy attempts to match the view permission
-  against the model's statements about which permissions are granted
-  to which principal to answer the question "is this user allowed to
-  do this".
-
-How ``repoze.bfg`` Processes a Request
---------------------------------------
-
-When a user requests a page from your ``repoze.bfg`` -powered
-application, the system uses this algorithm to determine which Python
-code to execute:
-
- 1.  The request for the page is presented to ``repoze.bfg``'s
-     "router" in terms of a standard WSGI request, which is
-     represented by a WSGI environment and a start_response callable.
-
- 2.  The router creates a `WebOb <http://pythonpaste.org/webob/>`_
-     request object based on the WSGI environment.
-
- 3.  The router uses the WSGI environment's ``PATH_INFO`` variable to
-     determine the path segments to traverse.  The leading slash is
-     stripped off `PATH_INFO``, and the remaining path segments are
-     split on the slash character to form a traversal sequence, so a
-     request with a ``PATH_INFO`` variable of ``/a/b/c`` maps to the
-     traversal sequence ``['a', 'b', 'c']``.
-
- 4.  Traversal begins at the root object.  For the traversal sequence
-     ``['a', 'b', 'c']``, the root object's __getitem__ is called with
-     the name ``a``.  Traversal continues through the sequence.  In
-     our example, if the root object's __getitem__ called with the
-     name ``a`` returns an object (aka "object A"), that object's
-     __getitem__ is called with the name ``b``.  If object A returns
-     an object when asked for ``b``, object B's __getitem__ is then
-     asked for the name ``c``, and may return object C.
-
- 5.  Traversal ends when a) the entire path is exhausted or b) when
-     any graph element raises a KeyError from its __getitem__ or c)
-     when any non-final path element traversal does not have a
-     __getitem__ method (resulting in a NameError) or d) when any path
-     element is prefixed with the set of characters ``@@`` (indicating
-     that the characters following the ``@@`` token should be treated
-     as a "view name").
-
- 6.  When traversal ends for any of the reasons in the previous step,
-     the the last object found during traversal is deemed to be the
-     "context".  If the path has been exhausted when traversal ends,
-     the "view name" is deemed to be the empty string (``''``).
-     However, if the path was not exhausted before traversal
-     terminated, the first remaining path element is treated as the
-     view name.  Any subseqent path elements after the view name are
-     deemed the "subpath".  For instance, if ``PATH_INFO`` was
-     ``/a/b`` and the root returned an "A" object, and the "A" object
-     returned a "B" object, the router deems that the context is
-     "object B", the view name is the empty string, and the subpath is
-     the empty sequence.  On the other hand, if ``PATH_INFO`` was
-     ``/a/b/c`` and "object A" was found but raised a KeyError for the
-     name ``b``, the router deems that the context is object A, the
-     view name is ``b`` and the subpath is ``['c']``.
-
- 7.  If a security policy is configured, the router performs a
-     permission lookup.  If a permission declaration is found for the
-     view name and context implied by the current request, the
-     security policy is consulted to see if the "current user" (also
-     determined by the security policy) can perform the action.  If he
-     can, processing continues.  If he cannot, an HTTPUnauthorized
-     error is raised.
-
- 8.  Armed with the context, the view name, and the subpath, the
-     router performs a view lookup.  It attemtps to look up a view
-     constructor from the ``repoze.bfg`` view registry using the view
-     name and the context.  If a view constructor is found, it is
-     converted into a WSGI application: it is "wrapped in" ( aka
-     "adapted to") a WSGI application using mapply.  The WSGI adapter
-     uses mapply to map request and environment variables into the
-     view when it is called.  If a view constructor is not found, a
-     generic WSGI ``NotFound`` application is constructed. 
-
-In either case, the resulting WSGI application is called.  The WSGI
-application's return value is an iterable.  This is returned upstream
-to the WSGI server.  The WSGI application also calls start_response
-with a status code and a header list.
-
-A Sample Application
---------------------
-
-A typical simple ``repoze.bfg`` application consists of four things:
-
-  1. A ``views.py`` module, which contains view code.
-
-  2. A ``models.py`` module, which contains model code.
-
-  3. A ``configure.zcml`` file which maps view names to model types.
-     This is also known as the "view registry", although it also
-     often contains non-view-related declarations.
-
-  4. A "templates" directory, which is full of zc3.pt templates.
-
-An application must be a Python package (meaning it must have an
-__init__.py and it must be findable on the PYTHONPATH).
-
-We don't describe any security in our very simple sample application.
-Security is optional in a repoze.bfg application; it needn't be used
-until necessary.
-
-views.py
-~~~~~~~~
-
-A views.py module might look like so::
-
-  from webob import Response
-  from repoze.bfg.template import render_template
-
-  def my_hello_view(context, request):
-      response = Response('Hello from %s @ %s' % (
-                          context.__name__, 
-                          request.environ['PATH_INFO']))
-      return response
-
-   def my_template_view(context, request):
-       return render_template('templates/my.pt', name=context.__name__)
-
-models.py
-~~~~~~~~~
-
-A models.py might look like so::
-
-  from UserDict import UserDict
-
-  from zope.interface import implements
-  from zope.interface import Attribute
-  from zope.interface import Interface
-
-  class IMyModel(Interface):
-      __name__ = Attribute('Name of the model instance')
-
-  class MyModel(UserDict):
-      implements(IMyModel)
-      def __init__(self, name):
-          self.__name__ = name
-          UserDict.__init__(self, {})
-
-  # model instance info would typically be stored in a database of some
-  # kind; here we put it at module scope for demonstration purposes.
-
-  root = MyModel('root')
-  root['a'] = MyModel('a')
-  root['b'] = MyModel('b')
-
-  def get_root(environ):
-      return root
-    
-configure.zcml
-~~~~~~~~~~~~~~
-
-A view registry might look like so::
-
-  <configure xmlns="http://namespaces.zope.org/zope"
-      xmlns:bfg="http://namespaces.repoze.org/bfg"
-      i18n_domain="repoze.bfg">
-
-    <!-- this must be included for the view declarations to work -->
-    <include package="repoze.bfg" />
-
-    <!-- the default view for a MyModel -->
-    <bfg:view
-        for=".models.IMyModel"
-        factory=".views.my_hello_view"
-        permission="repoze.view"
-        />
-
-    <!-- the templated.html view for a MyModel -->
-    <bfg:view
-        for=".models.IMyModel"
-        factory=".views.my_template_view"
-        name="templated.html"
-        permission="repoze.view"
-        />
-
-  </configure>
-
-templates/my.pt
-~~~~~~~~~~~~~~~
-
-A template that is used by a view might look like so::
-
-  <html xmlns="http://www.w3.org/1999/xhtml"
-       xmlns:tal="http://xml.zope.org/namespaces/tal">
-  <head></head>
-  <body>
-    <h1>My template viewing ${name}</h1>
-  </body>
-  </html>
-
-Running the Application
------------------------
-
-To run the application above, the simplest method is to run it
-directly from a starter script (although you might also use Paste to
-perform this task)::
-
-  from paste import httpserver
-
-  from repoze.bfg import make_app
-  from myapp.models import get_root
-  import myapp
-
-  app = make_app(get_root, myapp)
-  httpserver.serve(app, host='0.0.0.0', port='5432')
-  
-Viewing the Application
------------------------
-
-Visit http://localhost:5432/ in your browser.  You will see::
-
-  Hello from root @ /
-
-Visit http://localhost:5432/a in your browser.  You will see::
-
-  Hello from a @ /a
-
-Visit http://localhost:5432/b in your browser.  You will see::
-
-  Hello from b @ /b
-
-Visit http://localhost:5432/templated.html in your browser.  You will
-see::
-
-  My template viewing root
-
-
-Visit http://localhost:5432/a/templated.html in your browser.  You
-will see::
-
-  My template viewing a
-
-Visit http://localhost:5432/b/templated.html in your browser.  You
-will see::
-
-  My template viewing b
+Visit http://bugs.repoze.org to report bugs.  Visit
+http://svn.repoze.org to download development or tagged versions.