.. _glossary: ============================ Glossary ============================ .. glossary:: 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. Setuptools `Setuptools `_ builds on Python's ``distutils`` to provide easier building, distribution, and installation of packages. View A "view" is a callable which returns a response object. It should accept two values: context and request. 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"). Virtualenv An isolated Python environment. Allows you to control which packages are used on a particular project by cloning your main Python. `virtualenv `_ was created by Ian Bicking. 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 found during traversal; it becomes the subject of a view. Application registry A registry which maps model types to views, as well as performing other application-specific component registrations. Template A file that is capable of representing some text when rendered. Interface An attribute of a model object that determines its type. Location The path to an object in a model graph. 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 string or unicode object that represents an action being taken against a context. A permission 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. Permissions are used by the active to security policy to match the view permission against the model's statements about which permissions are granted to which principal in a context in order to to answer the question "is this user allowed to do this". Examples of permissions: "read", or "view_blog_entries". ACE An *access control entry*. An access control entry is one element in an *ACL*. An access control entry is a three-tuple that describes three things: an *action* (one of either ``Allow`` or ``Deny``), a *principal* (a string describing a user or group), and a *permission*. For example the ACE, ``(Allow, 'bob', 'read')`` is a member of an ACL that indicates that the principal ``bob`` is allowed the permission ``read`` against the context the ACL is attached to. ACL An *access control list*. An ACL is a sequence of *ACE* s. An ACL is attached to a model instance. An example of an ACL is ``[ (Allow, 'bob', 'read'), (Deny, 'fred', 'write')]``. If an ACL is attached to a model instance, and that model instance is findable via the context, it will be consulted by the security policy to determine wither a particular request can be fulfilled given the *authentication* information in the request. Authentication The act of determining that the credentials a user presents during a particular request are "good". ``repoze.bfg`` does not perfom authentication: it leaves it up to an upstream component such as ``repoze.who``. ``repoze.bfg`` uses the authentication data supplied by the upstream component as one input during authorization. Authorization The act of determining whether a user can perform a specific action. In bfg terms, this means determining whether, for a given context, the *principals* associated with the request have the requisite *permission* to allow the request to continue. Principal A *principal* is a string or unicode object representing a user or a user's membership in a group. It is provided by the *authentication* machinery upstream, typically. For example, if a user had the user id "bob", and Bob was part of two groups named "group foo" and "group bar", the request might have information attached to it that would indictate that Bob was represented by three principals: "bob", "group foo" and "group bar". Security Policy A security policy in bfg terms is a bit of code which accepts a request, the *ACL* associated with a context, and the *permission* associated with a particular view, and determines whether or not the principals associated with the request can perform the action associated with the permission based on the ACL. WSGI `Web Server Gateway Interface `_. This is a Python standard for connecting web applications to web servers, similar to the concept of Java Servlets. Zope `The Z Object Publishing Framework `_. The granddaddy of Python web frameworks. WebOb `WebOb `_ is a WSGI request/response library created by Ian Bicking. Paste `Paste `_ is a WSGI development and deployment system developed by Ian Bicking. LXML `lxml `_ is a XML processing library for Python.