Mailman 3 August 2003 - Twisted

[Twisted-Python] Revisiting sessions
by Edmund Dengler Aug. 9, 2003

Aug. 9, 2003

Just tried to get a session to apply to the entire website (rather than to one subdirectory). So, tried the following code: ======================================== from twisted.internet import reactor from twisted.web import static, server from twisted.web.woven import guard sessWrapped = static.Data("you should never see this", "text/plain") swChild = static.Data("NO", "text/plain") sessWrapped.putChild("yyy", swChild) swrap = guard.SessionWrapper(sessWrapped) da = static.Data("you … [View More]

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[Twisted-Python] Twisted Style
by Edmund Dengler Aug. 9, 2003

Aug. 9, 2003

Hi all! The Twisted stuff looks very good, and I think I am getting my head around to the way it works. I am looking for how I should be approaching a basic problem, and how to cast it in the Twisted model. Basically, I have a client transferring database rows to a server. I would like to transfer each row one-at-a-time, and I need information coming back to know whether the transfer was successful and to record in the client's database. I have tried the following (please note that the code … [View More]has been stripped to show the essence): Server (using PB) ----------------- Has a Perspective: class MyPerspective(pb.Perspective): def attached(self, clientref, identity): ... def attached(self, ref, identity): ... def perspective_transferXXX(self, XXX): ... ...create an app and a service... ...create appropriate perspective and identity things... ...listen at a socket... Client (1) ---------- class TransferClient: def __init__(self): def go(self): ...connect to server, defer to connection()... def connection(self, perspective): # Connection to server has been made ...save away perspective... self.transferCycle() def transferCycle(self): # Start a whole cycle (each cycle may transfer multiple rows) self.transferXXXs() def getXXXs(self): # Lets get the data to transfer ...setup database query, defer result set to transferXXXs()... def transferXXXs(self, XXXs): # We have our data from the query ...save away some state information... self.transferXXX(...first row...) def transferXXX(self, XXX): # Transfer a single row ...call remote perspective for XXX, defer return to doneXXX()... def doneXXX(self, result): # The row has been transferred and returned a result if successfully transferred: ...do appropriate work... if we still need to transfer more rows: self.transferXXX(...with the next row...) else: self.cycleDone() # Note: if we had other stuff, we would start them # transferring as well def cycleDone(self): # We have done a single cycle of transfers ...put a deferred for YYY seconds to start the cycle again... Now, this seems like an awful lot of methods simply to support deferred execution. Is there a way to use flows to acheive this? I have looked at the HowTo pages, but it is not clear how to use the Flow components within a PB model. Is there another approach? Regards! Ed [View Less]

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[Twisted-Python] Logging to stdout from trial
by Jonathan Lange Aug. 9, 2003

Aug. 9, 2003

The trial script takes a --logfile option, and writes all logs to this file. If you haven't noticed in the past, it's because it logs to test.log Below is a patch that sets the logfile to sys.stdout if the logfile is given as '-'. e.g. trial --logfile=- twisted.test.test_trial I'd commit this but I know very little about twisted's logging, and I don't know whether this solves the real problem or not. Index: twisted/scripts/trial.py ============================================================… [View More]

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[Twisted-Python] ADBAPI and individual rows
by Edmund Dengler Aug. 9, 2003

Aug. 9, 2003

Greetings! Digging a bit more into the DB side, and I wonder a bit about the API for adbapi. From what I can tell, the runQuery() will return a Deferred for the whole result set (which implies the result set is in memory). Is there a method or style for running a query in which each row will be passed back through a Deferred one at a time? (Basically, each cycle through reactor.run() would be returning a single row). What I am looking for is how to deal with a large result set without … [View More]

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[Twisted-Python] Woven: access to submodels
by Mary Aug. 8, 2003

Aug. 8, 2003

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. At the moment, I'm trying to replicate the authors functionality (2 different sets of pages: one which lists all the authors and links to their individual page; and one for each author, which lists their … [View More]individual articles. The /authors/ page (listing all the authors and linking to their individual page) is generated by objects of the AuthorsPage subclass. 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. 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? For example, should I be passing submodels around like that at all? If so, is there a higher level call I should make to access the submodel? The two classes following are the AuthorsPage and IndividualPage classes described above. Thanks, -Mary class IndividualPage(page.Page): # getTemplate munges two template files together template = getTemplate("/home/mary/cvs/Projects/Eye/author-page.html") def initialize(self, *args, **kwargs): self.amodel = kwargs['amodel'] def wmfactory_author(self, request): return self.amodel['author'] class AuthorsPage(page.Page): template = getTemplate("/home/mary/cvs/Projects/Eye/authors-page.html") def initialize(self, *args, **kwargs): self.dbpool = kwargs['pool'] self.authors = None def wmfactory_authors(self, request): query = self.dbpool.runQuery("SELECT DISTINCT posts.name, link, password FROM authors, posts WHERE authors.name = posts.name ORDER BY name;") query.addCallback(self.makeAuthors) return query def makeAuthors(self, rows): ''' Construct self.authors, return them as a list @return a list of author dictionaries ''' authors = {} for row in rows: (name, link, password) = row authors[name] = { 'name' : name, 'link' : link, 'password' : password } return authors def wvfactory_alink(self, request, node, model): return AuthorLink(model) def getDynamicChild(self, name, request): return IndividualPage(amodel=self.getSubmodel('authors')[name])) [View Less]

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[Twisted-Python] UDP and factories
by John Janecek Aug. 8, 2003

Aug. 8, 2003

I am attempting to use DatagramProtocol with a factory are u supposed to use DatagramProtocol with a factory ?? am i out to lunch ? ie from twisted.internet.protocol import DatagramProtocol from twisted.internet import reactor from twisted.internet.protocol import Factory class Echo(DatagramProtocol): def datagramReceived(self, data, (host, port)): print "received %r from %s:%d" % (data, host, port) self.transport.write(data, (host, 7000)) echo_factory = Factory() … [View More]

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[Twisted-Python] Woven and sessions
by Edmund Dengler Aug. 8, 2003

Aug. 8, 2003

Okay, been playing around with the session stuff. Still trying to get my head around how ths is structured. Created a site. Created a single child "xxx". Created a session wrapped child "yyy". Now, "http://localhost:8080/xxx/session-init/yyy" will cause a cookie to be loaded, and a redirect to "http://localhost:8080/xxx/yyy?__session_just_started__=1" if I accept the cookie. Rejecting the cookie causes something akin to "http://localhost:8080/xxx/e11a075ad25656dca2b90022507746b6/yyy"… [View More]

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[Twisted-Python] Win32 installer for Python2.3
by Mike Mueller Aug. 8, 2003

Aug. 8, 2003

I am looking for twisted1.0.6 for Python 2.3 for Windows. There is a installer for Python2.2, but I could not find anything for 2.3. I do have VC++ 6.0 but could not figure out how to compile from the UNIX sources. It would be nice if somebody could help me. Thanks. Mike

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[Twisted-Python] Woven and submodelling through deferreds
by Syver Enstad Aug. 7, 2003

Aug. 7, 2003

I asked on the #twisted irc channel today about this, and Itamar answered that it was possible but maybe only in CVS, I was also directed to this list as the proper channel to ask woven questions. I have the following setup: class MyPage(page.Page): def wmfactory_myClass.... ... some code that does a asynch operation and return a deferred deferred.addCallback(self._cbMyClass) return deferred def _cbMyClass(self, result): return MyClass(result) class … [View More]

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[Twisted-Python] Woven and XSL
by Edmund Dengler Aug. 7, 2003

Aug. 7, 2003

Hi all! Having a look at the Woven component, and I have a question. Does Woven support some form of XSL transformations, or would I need to "emulate" this feature by using extremely simple XHTML pages (basically begin/end HTML with a model/view call), perform said transformations internally, and return a ready to render DOM model? The reason I ask is we are using some fairly complex XSL code to render pages to maintain a consistent look and feel (things such as placing the alignment in the … [View More]

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