Mailman 3 October 2003 - Twisted

[Twisted-Python] change submodel in a form
by vicky lupien Oct. 31, 2003

Oct. 31, 2003

I have a web base application. I want to change the data in the model so that it will be update in the form when a post my form. Here's my code: from twisted.web.server import Site from twisted.internet import reactor from twisted.web.woven.page import Page from twisted.web.woven.form import FormProcessor from twisted.python import formmethod as fm from twisted.web.woven import input, controller from twisted.web import domhelpers class FormPage(Page): template = '''<html> <head><title>a form page</title> </head> <body bgcolor="c0c0c0">  <br/><br/> <form action="post" method="post" enctype="multipart/form-data"> <table border="0"> <tr> <td align="right" valign="top">Argument #1:</td> <td valign="top"><input type="text" name="arg1" value="" size="60" controller="int" /> <div class="formDescription">Hooray it is an argument. </div></td> </tr> <tr> <td align="right" valign="top">Integer Field.: *</td> <td valign="top"><input type="text" name="arg2" value=""/> <div class="formDescription"> </div></td> </tr> <tr> <td align="right" valign="top">TEXT PLS:</td> <td valign="top"><textarea wrap="virtual" rows="10" cols="60" name="arg5">HERE IS THE DEFAULT OMG!@#!.</textarea> <div class="formDescription">it is some text </div></td> </tr> </table><input type="submit" /> </form> </body> </html> ''' def __init__(self): Page.__init__(self) def checkName(self, request, name): if name is None: return None return True #def commitName(self, request, name=""): # print self.model def wvupdate_arg1(self, request, widget, model): pass def wmfactory_arg1(self, request): return request.args.get('arg1') def wcfactory_int(self, request, node, model): self.submodel = self.model.getSubmodel(request, "arg1") return input.InputHandler( model, name = "arg1", check = self.checkName, submodel = self.submodel) #commit = self.commitName def wchild_post(self, request): return self reactor.listenTCP(8585, Site(FormPage())) reactor.run() Here's the error I get: exceptions.TypeError: process() keywords must be strings I know that the error comes from controller but I don't know how to correct it. Maybe the error is because I'm not very familiar with form. Thx in advance, Vicky

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[Twisted-Python] ANN: Twisted 1.1.0, the framework of *your* internet
by Itamar Shtull-Trauring Oct. 31, 2003

Oct. 31, 2003

What's New in 1.1.0 =================== - twisted.application, an updated deployment and configuration library. - Mac OS X GUI event loop integration (requires PyObjC). - New howtos, including a tutorial, and more web framework docs. - The documentation is now better organized, up-to-date with the latest APIs, and in some areas much more extensive. - Removed a number of broken, unmaintained and unused packages and modules. - Bug fixes and feature enhancements.

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[Twisted-Python] Dual Reactor Script
by Mark Evans Oct. 31, 2003

Oct. 31, 2003

This question pertains to the use of dual reactors in a single Python script. The script runs on Windows 2000 and has the nature of a daemon which translates between two protocols on either side of it. Side A = Telnet protocol ("raw" type) over TCP transport to embedded device ASCII data Side B = Custom binary protocol (bits, bytes) over UDP transport binary data Now the Twisted Matrix samples I've examined all do this in their main entry: reactor.listenTransport(port, protocolFactory) reactor.run() However I have TWO transports and TWO protocols. So the question is how to properly configure the reactor(s) in my script. Any advice, in particular? How should such a daemon be structured properly in TM? Threads? Two scripts? Please advise. I'm sure there's a simple way but always like to cover my bases with the gurus. Probably I need only one reactor, configured in a particular way to handle two protocols and transports. Thanks! Mark

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RE: [Twisted-Python] Woven, using microdom.lmx, and HTTP requests
by Hegedus, Matthew S Oct. 31, 2003

Oct. 31, 2003

Well it's almost the weekend and this is my work email, so I must kick off a few questions before I leave. Let me start off by thanking you all again for being so helpful. I recognize you are busy people, so for taking time to help me and others, I salute you ;). Up to this point I've coded up a Twisted test program that has a global list of lists: ex: [['a','b','c'],['d','e','f'],['g','h','i'], ...] I generate dynamic xhtml, creating a form(method='get') containing a table for my list data. Each sublist is a row of this table, and at the end of each row (also a part of the table) is a 'REMOVE' button. Microdom.lmx code for 'REMOVE' button: tr.td().input(type='submit', \ name=str(buttonID), \ value="REMOVE", \ view='rmExercise', \ model='listData') ... The corresponding view code for the buttons: def wvupdate_rmExercise(self, request, node, listData): print request.args print request.args.keys() if ~pseudocode~ request.args.keys()[0] is valid ~psuedocode~: del listData[int(request.args.keys()[0])] request.args.clear() The page with the table gets served up and looks ok, but strange things happen (unexpected HTTP events) when I hit the browser's reload button. I can get into situations where hitting reload will generate three input submit events as if I clicked my remove button three times. This events lead to the deletion of a few sublists. What in the world could be going on? Another question: When the input buttons view is called, list data is modified, but the page does not get re-rendered. Is adding the line... self.render(request) ...the correct way to handle this issue? And another question: I am browsing the pages on the same machine that I'm serving them from. It seems that sometimes reloading the page in the browser takes a while (more than 10 seconds in some cases). Is there some reason for this? Thanks again, Matthew

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[Twisted-Python] win32 twisted 1.1.0 import error
by marcin andrzejewski Oct. 30, 2003

Oct. 30, 2003

hi, i am quite new to twisted and have one lame question. why importing modules from directory of .rpy file doesn't work in twisted 1.1.0 for win32? it works perfectly fine in 1.0.7.. -- regards, marcin andrzejewski mailto:keson@post.pl

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Re: [Twisted-Python] twisted.web and MySQLdb
by phil＠bubblehouse.org Oct. 30, 2003

Oct. 30, 2003

well, my only use of the db object directly is for actually updating the table. my particular implementation would have far more views than updates, so i was going to cache the common data, or possibly pre-render html... wouldn't you say that these performance issues are as much of a consequence of poor design as much as the choice to use SQL? obviously db calls are expensive...but some of the benefits of a portable datasource are worthwhile. as nice as it would be to live in a world where pickle was a common data format, we're not there yet... > Date: 29 Oct 2003 06:28:17 -0000 > From: Moshe Zadka <m(a)zadka.site.co.il> > Subject: Re: [Twisted-Python] twisted.web and MySQLdb > To: twisted-python(a)twistedmatrix.com > Reply-To: twisted-python(a)twistedmatrix.com > > I won't reply to your question here, I'm sure someone more competent > than me can do so. > I will take a minute to note that for some reason, the instinct of > web developers has been to immediately write applications in the > LAMP model. While twisted.web is a perfectly good substitute for > A, and can indeed be used this way, it is much more capable. > > LAMP -- Linux Apache MySQL PHP [each of those has variants] > > Linux (and most other things in the "L" place, such as FreeBSD) has > an incredibly fast fork() operation. This leads people to write their > web code with the process-per-page model. Apache optimizes this by > preforking, making such code actually scalable enough to deliver good > response times. However, suddenly there is a problem: since different > processes are likely to deal with the same user, memory becomes fragile. > It is unsafe to put things in memory: processes switch users, get born > and die too often. In Linux, and most other Unices, file locking has > been a thorny issue. So instead of putting data in files, where the > subtle semantics of locking and concurrency should be dealt with, > data tends to end up in the database. That means *all* data. Sessions. > Temporary "show this message when the user finished his redirect loop". > Etc. etc. Once all the data is in MySQL, which is the easiest database to > set up, it becomes natural for the average page to be a "glorified > select". > PHP was designed for this exact scenario: take a select table and spruce > it up with HTML. > > Unfortunately, what LAMP deals to is exactly to this: inevitably, all > pages are just spruced up select-tables. This makes programming somewhat > unnatural unless you're programming a database viewer. > > With twisted.web, you don't have these problems. It is easy to keep data > in files, because locking is not an issue. It is easy to cache data in > memory > because everything is served from a single process. If you need to attach > state to a user's session, you can just keep an object in the session. > This means programming twisted.web should be a lot more like writing > a GUI application, and a lot less like writing select-with-HTML. > You should probably reconsider whether you really want MySQL. It adds > complexity to your application, and the gain is usually small. Putting > persistent data in files, and using liberal caching schemes, also plays > on the core advantage of Linux (and similar) -- it uses the incredibly > optimized caching algorithms.

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[Twisted-Python] twisted.web and MySQLdb
by phil＠bubblehouse.org Oct. 30, 2003

Oct. 30, 2003

so i probably should have subscribed to this list months (years?) ago, but only now am i getting up to speed on the twisted craziness... anyways, i'm toying with twisted.web, and i'm working on making a web application. i'm also using the TAP interfaces to take care of run-time options, etc.... I'm using MySQLdb to interface with my sql server, but i'm not really sure what to do with my connection object once it's created. i want to put it somewhere that will be easy to access for the rest of the modules, but obviously i don't want it to be persisted when the TAP is saved.... i guess a lot of my problem is that i'm still trying to figure out some of the structure when working with the framework... i want to use the command-line options to specify a user/passwd for the database. i guess this means i want to create my connection instance in the updateApplication method, since it has a options reference, but i don't know how to make it so the connection object isn't persisted, but created new each time the server is started.... any help would be appreciated.... -phil

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RE: [Twisted-Python] Woven, using microdom.lmx, and trying to use style sheets
by Hegedus, Matthew S Oct. 30, 2003

Oct. 30, 2003

Setting color through microdom.lmx just doesn't seem to be working for me. I can view the source of the web page xhtml generated (browser right-click, view source), and everything looks good, but I just don't see the browser actually rendering page features in the color I specified. All of the lmx generated xhtml is literally rendered black and white. I am using style sheets. Do I need to do some sort of rerender trick? <UPDATE before I send this out: It appears NONE of the style sheet stuff has any effect on the look of the web page when implemented using microdom.lmx.> To clarify, I receive no errors and from the looks of things the xhtml code generated by lmx seems legit. Here is the key snippets of code(hopefully formatting will remain intact): XHTML template: <html> <head> <style type="text/css"> table.exerciseTableClass {border: 0; cellspacing: 2;} table.exerciseTableClass tr.tableHeadingClass {color: white; background-color: darkslateblue;} </style> </head> <body> <h1 ~some stuff~></h1> <table model="amodel" view="aview"> </table> </body> </html> Python code: ... def wvupdate_aview(sel, request, node, data): lmxnode = lmx(node) d = lmxnode.div() #These next two lines don't seem to do anything in terms of style. #It's as if I just made a plain-old table, and a couple of plain-old rows t = d.table(_class='exerciseTableClass') t.tr(_class='tableHeadingClass') t.td().text(data.label1) t.td().text(data.label2) ... Have any of you run into similar troubles, and if so what did it take to fix the problem? Thank you, Matthew -----Original Message----- From: Matthew Scott [mailto:twisted@goldenspud.com] Sent: Wednesday, October 29, 2003 12:29 PM To: twisted-python(a)twistedmatrix.com Subject: Re: [Twisted-Python] Woven, using microdom.lmx, and trying to use style sheets On Wednesday 29 October 2003 11:59 am, Donovan Preston wrote: > On Oct 29, 2003, at 12:44 PM, Hegedus, Matthew S wrote: > > I tried t.tr['class'] = "mySpecialTableRowStyleClass" but then I got > > bitched at with an "object does not support item assignment". > > Thanks, > > t.tr(_class="mySpecialTableRowStyleClass") > > Since class is a python keyword, the special case of having a leading > underscore is used. I ran into this recently too :) Just an extra note, the leading underscore is not required when setting the class attribute of an existing node: node = t.tr() node['class'] = 'mySpecialTableRowStyleClass' -- Matthew Scott http://goldenspud.com/ _______________________________________________ Twisted-Python mailing list Twisted-Python(a)twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python

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[Twisted-Python] HTTP Server - UDP
by Daniel Gomes Oct. 30, 2003

Oct. 30, 2003

Thomas Weholt, Hello! My name is Daniel Gomes and I am a Computer engineering studend in Brazil. I am researching about a UDP HTTP Server and and I read that you have done one. I was wondering if you could tell me where to find some information about this or even let me see you server (if you dont mind). Best Regards, Daniel Gomes dddgomes(a)yahoo.com.br Recife - PE - Brasil Yahoo! Mail - o melhor webmail do Brasil http://mail.yahoo.com.br

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Re: [Twisted-Python] twisted.web and MySQLdb
by ecn＠metaslash.com Oct. 30, 2003

Oct. 30, 2003

> Can you qualify "long time"? And what's the bottleneck? At the scale > of 100K or so function calls, Python isn't egregiously slow, certainly > not slow enough to not be able to outrun TCP connection setup...? Hmm, maybe a minute? I forget exactly. It was like 4x slower than C++. (I'm running Linux 2.6test1 with dual AMD Athlon MP/2000's). I posted a bug in the poll reactor some time ago. I was testing an epoll() subclass I had written at the time. To test the server, I had written a C++ program to connect, asynchronously, over the loopback device. I had to insert a pause in the connector to avoid connection failures. Mind you, I had to create several "fake" networks in order to have enough ports for all those simultaneous connections. This was an absurd number of connections (10K, 20K, 40K, etc). The default TCP connection timeout on Linux is ... what? like 61 seconds or something? That was the number I was hitting. Everything ran well, up to about 8-10K. Then it would fall behind, and then I was at the mercy of TCP retries. This customer was particularly performance oriented, so I didn't think that python was going to fly with them, anyhow. But it is so much simpler to code/debug/test, I wanted to see how well it would perform. I tweaked the acceptor to just accept all the connections it could, and that was too slow. It didn't even get into the event loop. I also tweaked ACE to accept connections faster, too. It's just a tough problem. -Eric

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