I apologize for not responding immediately. On Saturday, July 12, 2003, at 7:21PM, Mary wrote:
I'm trying to replicate the functionality of http://eyes.puzzling.org/ (currently powered by a bunch of Python CGI scripts running on an Apache webserver) in Woven.
eyes.puzzling.org is a kind of a minimalist blog, with pages that list recent entries, the authors of the entries, and so on.
Cool! Have you seen Blog, in the twistedmatrix.com cvs? It is out of date and needs work, but feel free to steal the code/take over the project/whatever. <snip>
For each author, I would like to generate a /author/AUTHORNAME/ page which lists their individual entries. I am trying to create these pages from AuthorsPage's getDynamicChild method. The idea is to pass the already constructed submodel -- a dictionary representing the individual author -- to the IndividualPage object I will construct to represent the individual author's page, rather than have IndividualPage make its own database query for that information.
That's good -- that sounds like a good design. There are no rules when it comes to Woven architecture, but reusing your Model objects, and model production logic, across multiple pages sounds like a good idea to me.
At present, as you can see below, I'm using getSubmodel to retrieve the (dictionary) submodel associated with a particular author. However, this returns a twisted.web.woven.model.DeferredWrapper instance, rather than the dictionary itself. Should I make IndividualPage add callbacks to the DeferredWrapper, or am I missing something crucial about retrieving submodels or is this model more fundamentally incorrect?
As Moshe said in his reply, currently the URL traversal process is synchronous, so if you need to wait on a Deferred to construct the next URL segment Resource you're going to be doing a lot more work than you should have to. Woven attempts to hide Deferreds from the programmer by pausing rendering and resuming it when the Deferred fires. So, fortunately, things may be simpler than they seem. You can just pass the DeferredWrapper as the Main Model to the next Page instance you construct, and as long as you are going to be rendering that Page next, Woven will just wait on it as it would any other Deferred. from twisted.web.woven import page from twisted.web.woven import model from twisted.internet import defer from twisted.internet import reactor class DeferredProducer(model.MethodModel): def wmfactory_someDeferred(self, reqeuest): d = defer.Deferred() reactor.callLater(0.5, self.produce, d) return d def produce(self, d): d.callback( "Hello, here is some text" ) def wmfactory_someNotDeferred(self, request): return "Hi there" class MainPage(page.Page): template = """<html> <h3 model="someNotDeferred" view="Text">qawsf</h3> <span model="someDeferred" view="Text">qwensd</span> </html>""" def getDynamicChild(self, name, request): return ChildPage( self.model.getSubmodel(request, 'someDeferred')) class ChildPage(page.Page): template = """<html> Hello! Our main model is a deferred, so the next node will have to wait <span model="." view="Text">ncxnz</span> </html>""" resource = MainPage(DeferredProducer())