[Twisted-web] Re: Remembering things in context from a Realm

[Alex Levy]

On 9/28/2004, "Matt Goodall" <matt at pollenation.net> wrote:

>On Tue, 2004-09-28 at 14:48, Donovan Preston wrote:
>> On Sep 28, 2004, at 12:41 AM, Alex Levy wrote:
>>
>> > I have a Realm class that does something akin to the following:
>> >
>> > class MyRealm:
>> >   def requestAvatar(self, id, mind, *interfaces):
>> >     if IResource is in interfaces:
>> >       user = figureOutWhoTheUserIs(id)
>> >       resource = getResourceForUser(user)
>> >       resource.remember(user, ICurrentUser)
>> >       return (IResource, resource, lambda:None)
>> >
>> > ...and this doesn't seem to be working with the ubiquitous context.
>> > _Should_
>> > it work, or do I need a new way to do something like this?
>> >
>> > Help is appreciated; I'm trying hard to get back in the loop. :/
>>
>> You are going to have to put user as an attribute on resource, then
>> remember it in the context in an overridden locateChild.
>
>Or, you can create a IResource wrapper that is used like this from
>requestAvatar:
>
>	return (IResource, RememberWrapper(resource, user), lambda:None)
>
>and looks like this (untested):
>
>class RememberWrapper:
>    __implements__ = inevow.IResource,
>
>    def __init__(self, resource, user):
>        self.resource = resource
>        self.user = user
>
>    def locateChild(self, ctx, segments):
>        ctx.remember(self.user, ICurrentUser)
>        return self.resource, segments
>
>    def renderHTTP(self, ctx):
>        ctx.remember(self.user, ICurrentUser)
>        return self.resource.renderHTTP(ctx)
>
>This avoids setting attributes on the resource which means you can reuse
>a single *real* resource object if that makes sense to your application.

This is what I'd expected to do -- instead of just returning a regular
resource, return an EverythingLivesInsideHereResource (with a more
suitable name) that contains everything the site needs to pass down to
the resources.

Still, passing the context through the entire resource chain will let me
cut out a _lot_ of cruft from [Paya]go. Kudos! :)