beforeHTTP ( context )

Invoked before publication by IHTTPHandler adapter

This can be used to enforce any preconditions for interacting with this object via the web. For example, an e-commerce "checkout" traversable might want to ensure that there is an active session and there are items in the user's cart, or that the connection is secure.

This method is only invoked when the traversable is about to be traversed into via a web request, AND the target object does not have any other adaptation to IHTTPHandler. It is not invoked when app-server code traverses a location (e.g. by paths in page templates, including ++id++ paths that pass through a location but don't "stop" there).

Traversables can take advantage of this to have different security restrictions for app-server code and via-the-web URL traversal. Resources, for example, do not do security checks in traverseTo(), only in beforeHTTP(), thus ensuring that app-server code can access all available resources, whether they are available to the user or not.

This method must return either the passed-in context, or a new traversal context to be used in its place. Note also that if your object implements IHTTPHandler, or you are implementing an adapter to IHTTPHandler, you must call this method yourself, since it is normally only invoked by PEAK's adapter from IWebTraversable to IHTTPHandler.

getURL ( context )

Return this object's URL in traversal context context

traverseTo (
        name,
        context,
        default=NOT_GIVEN,
        )

Return next ITraversalContext, or raise NotAllowed/NotFound