Mailman 3 October 2003 - Twisted

[Twisted-Python] Woven Tutorial alpha is up for review
by Jonathan Simms Oct. 14, 2003

Oct. 14, 2003

Hello all, I've put together a tutorial on using Woven that is geared towards new users, and I'm making it available for your edification (and critique). I'm still working on it, but I'd say it's about 85% complete. You can view it at: http://www.embassynetworks.com/woven-tut/toc.xhtml As of this moment, the program is not in a downloadable state (as I've got to re-arrange my source tree), but as soon as it is, I'll make it available. Thanks, and enjoy! -Jonathan Simms (slyphon) ---… [View More]

1 0

[Twisted-Python] Twisted's cfreactor + PyObjC = Asynchronous Networking on OS X
by Bob Ippolito Oct. 14, 2003

Oct. 14, 2003

For those of you who don't watch Twisted CVS, cfreactor is officially out of the sandbox. cfreactor is the CoreFoundation integration reactor for Twisted ( http://www.twistedmatrix.com/ ), which means that you can now seamlessly integrate Cocoa and Twisted (without digging around in my sandbox, that is). If you're running OS X and you'd like to play with cfreactor, check out the latest CVS and do a python setup.py install (so that it can build twisted/internet/cfsupport.so -- ignore the … [View More]

2 1

[Twisted-Python] PB/wx example pbwxthingy
by Stephen C. Waterbury Oct. 14, 2003

Oct. 14, 2003

Twisted Gurus, For the 1.1 release, you might want to consider replacing the old "wxdemo" example, which is pretty lame, with the really cool wx-and-PB example posted to the list by Axel Busch on Sept 20. It works great and is an impressive example of both PB and the application of Uwe Schroeder's recipe that enables the use of the reactor within a wxPython app without causing menus and modal dialogs to hang: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/181780 (There's also a … [View More]

1 0

[Twisted-Python] Rendering woven pages offline.
by Syver Enstad Oct. 12, 2003

Oct. 12, 2003

I need to send a mail containing a woven page. Is it easy to setup rendering the page offline rather than to an HTTP request? -- Vennlig hilsen Syver Enstad

2 1

[Twisted-Python] disabling/resuming connections
by Ruslan Spivak Oct. 12, 2003

Oct. 12, 2003

Hello. Is it possible programmatically tell my server to stop accept connections from remote clients and then enable it programmatically when i need? I use PB based server. Thanks in advance. Best regards, Ruslan

2 1

[Twisted-Python] woven dynamic table cell updating
by Justin Johnson Oct. 10, 2003

Oct. 10, 2003

I have some code (attached ui.py) that creates a table displaying results of running tasks. The rows are tasks and the columns are step numbers in that task. I use this table when I make a bunch of requests into PB servers running on multiple machines. As those tasks move forward, the PB server calls back into the client (which has a perspective_* method) to update the status of that task/step. An 'I' appears for 'in progress', 'S' for 'success', and 'F' for 'failure'. If there are … [View More]

2 4

[Twisted-Python] resource navigation
by Syver Enstad Oct. 10, 2003

Oct. 10, 2003

Let's say I have a hierarchy of resources like this: grandparent parent1 parent2 child1 child2 grandchild Is there an easy way to know at runtime what url goes to let's say parent2? I am interested primarily because I am interested in having as self contained page classes as possible and hardcoding links to parent2 in grandchilds view template seems brittle. Woven seems to be strangely symetric regarding models and pages. An example is getChild / getSubmodel and on top … [View More]

2 1

[Twisted-Python] newbie: groking flows
by Nesbitt, Steve Oct. 9, 2003

Oct. 9, 2003

All: I'm trying to grok flows in general and how to mix cooperative and blocking flows in particular. I've been reviewing the documentation and have a better understanding, but something is still eluding me. I'm hoping someone can help me out with either some pseudocode (or a real world example) Here's my design problem: When I start the server, I generate a series of lookup table objects (called "registries") by parsing through a series of XML files. XML-RPC requests come in requesting … [View More]information and these registries are then used to help fulfill the request. Periodically, albeit infrequently, one of the original source XML files may change and an XML-RPC call will request that the registries be updated/regenerated. During the regeneration process, which can take multiple seconds, all lookup and additional regeneration requests should block until completion of the regeneration. Once completed, blocked requests should resume. Based on my reading I think this is what should do: 1) Periodically during a lookup call a flow.Cooperate event to allow other lookup events from other requests to be handled. 2) To avoid a regeneration event in the midst of a lookup, I should make sure that a flow.Cooperate event is *not* issued at any time during a critical part of the lookup process ( In other words one can consider the code executed between two flow.Cooperate statements as a transaction) 3) When I start a regeneration event I should wrap the regeneration method in a flow.Block controller. So here are some specific questions: 1) Is my basic understanding correct? In particular am I guaranteed correct behavior using the above outline? 2) Am I correct in believing that wrapping a method in flow.Block actually executes the method? That is, the statement flow.Block( foo( bar ) ) executes foo.bar immediately? 3) How do I access the results of flow.Block( foo( bar ) )? In particular how do I see the return result or any exceptions tr\hrown by foo? 4) Am I correct in believing that while flow.Block( foo(bar) ) is executing any incoming requests will be prevented from executing? 5) Is it possible to defer a blocking method? This covers the scenario where two regeneration events occur within the same time frame. Thanks in advance for the help and sorry for the length of the post. I'll be glad to write thisx up as a how to if that would be helpful. Thanks in advance for the help. -steve Stephen Nesbitt Senior Configuration Management Engineer The Cobalt Group snesbitt(a)cobaltgroup.com This e-mail transmission contains information intended only for the use of the recipient(s) named above. Further, it contains information that may be privileged and confidential. If you are not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this message (including any attachments) is strictly prohibited. If you have received this e-mail in error, please notify the sender by reply e-mail and then delete this message from your mail system. Thank you for your compliance. [View Less]

2 1

[Twisted-Python] guard.UsernamePasswordWrapper errback
by Justin Johnson Oct. 9, 2003

Oct. 9, 2003

I got a woven login page working by copying Twisted/sandbox/glyph/dynademo where guard.UsernamePasswordWrapper is used. In the dynademo example, if the password is entered incorrectly, an error page displays as documented in the doc strings for UsernamePasswordWrapper. The problem is that it displays the error on a new page. I'd like to capture the error in an existing html file. So I added the errback argument as follows: r = guard.SessionWrapper(guard.UsernamePasswordWrapper(p, callback=… [View More]

1 0

Re: [Twisted-Python] Woven page instances deferring to each other...
by Stuart Hungerford Oct. 9, 2003

Oct. 9, 2003

Quoth twisted-python-request(a)twistedmatrix.com: >On Wed, Oct 08, 2003, Stuart Hungerford wrote: >> In another Woven page the application can detect these >> "error" states and I would like to optionally "defer" the HTML >> generation to the existing error pages: > >I *think* here you mean "I'd like totally different HTML generated if >there is an error state", rather than "my check for the error returns a >Deferred object". Let me know if I'm wrong. … [View More] Quite right -- I did mean "totally different HTML", it was a poor choice of terms after too little thought ;-) >Assuming you meant "I'd like totally different HTML generated if >there is an error state" you probably do want macros or something like >them. The best documentation I've seen on this is here: >http://twistedmatrix.com/pipermail/twisted-python/2003-June/004662.html Thanks -- I'll check that out. >Followup... > >A nicer solution may be to have the parent Page (by this I mean >http://example.com/bob/ is a parent and http://example.com/bob/result/ >is a child -- parents in the URL structure) do the check and return an >object of a different Page class, something like: > >class MyParentPage(page.Page): > > def getDynamicChild(self, name, request): > > if error_condition_1: > return ErrorPage1() > elif error_condition_2: > return ErrorPage2() > else: > return NormalChildPage() > >If there's any way you can determine if the error has happened before >the child page starts rendering, then I suspect it would be nicer to do >the error check at child creation time, rather than when the child >renders. I can see the sense in this approach, but it does have the effect pushing implementation of business rules from the wvupdate_foo() functions into creation time checks. Although, that may be a good thing, I haven't really got a feel yet for what constitutes "good" Twisted or Woven idioms. >[...] >Since woven renders the entire page before it calls request.write, any >portion of the view rendering code which detects an error is able to >call request.redirect (because we can still set headers since we >haven't written any of the body yet). Just thought I'd chuck that out >there, it may be totally irrelevant. This could also be very useful, as Mary points out, it gives us a choice of where the application logic can be based. Many thanks to all for the help! Cheers, Stu -- :: Stuart Hungerford (stuart.hungerford(a)anu.edu.au) :: ANU Internet Futures Group [View Less]

1 0