Mailman 3 May 2004 - Twisted

[Twisted-Python] (Un)Twisted Clients and Servers (newbie)
by Bill la Forge 27 May '04

27 May '04

Finally wrote my first Twisted-based client and server: http://compstrm.sourceforge.net/twcs/csprotocol.html Both the client and server are implemented as light- weight processes, where pipes are used for reading and writing to remote processes. This allows the logic flow to be more straight-line. I'm also "translucently" switching threads in the client, using in-line method calls, so that reads and writes to the client do not block the main thread. (I'm trying to show how much clearer asynchronous programming can be using Computational Streams.) ===== Bill la Forge http://www.geocities.com/laforge49/ ________________________________________________________________________ Yahoo! India Matrimony: Find your partner online. http://yahoo.shaadi.com/india-matrimony/

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[Twisted-Python] Lore question/ latex output question
by Schneider, Michael 27 May '04

27 May '04

Hello All, I have been using lore for a project that I have been working on, and it is a great tool. I have a quick question. Does anyone know how to get the <pre>...</pre> tags to appear as shaded on the latex/pdf output? The generated latex looks like \\begin{verbatim} is being output at the start of the pre and \\end{verbatim} is being output at the end of the pre. I am trying to get the same output format as html output. Thank you very much, Mike ---------------------------------------------------------------- Michael Schneider Senior Software Engineering Consultant UGS PLM Solutions - an EDS Company "The Greatest Performance Improvement Is the transitioning from a non-working state to the working state" >

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RE: [Twisted-Python] Java question
by Schneider, Michael 26 May '04

26 May '04

Thank you Itamar, I will download this and look at it. Mike ---------------------------------------------------------------- Michael Schneider Senior Software Engineering Consultant UGS PLM Solutions - an EDS Company "The Greatest Performance Improvement Is the transitioning from a non-working state to the working state" > -----Original Message----- > From: twisted-python-bounces(a)twistedmatrix.com > [mailto:twisted-python-bounces@twistedmatrix.com]On Behalf Of Itamar > Shtull-Trauring > Sent: Tuesday, May 25, 2004 1:29 PM > To: Twisted discussion stuff > Subject: Re: [Twisted-Python] Java question > > > On Tue, 2004-05-25 at 13:23, Schneider, Michael wrote: > > > This may be a little off topic, but is there a package for > > Java that provides any of: > > - reactors > > - deferred > > - Protocol Objects like twisted > > I started some work on improving EIO, originally written by Zooko. It > doesn't have a concept of Deferreds yet, and some of the APIs will no > doubt change, but it's a start. > > http://java.twistedmatrix.com/eio/ > > -- > Itamar Shtull-Trauring http://itamarst.org > > > > _______________________________________________ > Twisted-Python mailing list > Twisted-Python(a)twistedmatrix.com > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python >

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[Twisted-Python] How to organize a web application?
by Alexander May 26 May '04

26 May '04

I am looking for advice on how to organize a web application. I've never written a web application before, and would appreciate any insight into best practices and overall structure. I have html pages, html templates, an underlying database, and (hopefully) an understanding of twisted and nevow. What is the best way to glue all of this together? For example, what is the best way to associate derived rend.Page classes with html templates? I'll have all these different data and render functions that could potentially be used by many different templates. Do I create one monster rend.Page derived class responsible for servicing all the possible display an render functions? That seems wrong. What's the alternative? What is the best way to manage links? The html page template will link to each other, mostly at the discretion of the html designers (admittedly me at first). Should I utilize the underlying file system to define the link structure as I might do for static html site? If yes, should I use static.File and create a special resource type for the html template and then return rend.Page derived classes? Or should I do something else all together? What is the best way to manage state (non database)? Cookies or mugged URLS mapped to closures seems like it would work well. Perhaps someone has some experience doing this? I took a look at the Quotient source, and did not see any html templates at all, so I assume all the html generation is occurring dynamically via Stan or some other method. Likewise for nevow Calendar example which has a single html template and links to dynamically generated pages (I'll probably need to do that too). Thought and comments? Thanks, Alex

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[Twisted-Python] Java question
by Schneider, Michael 26 May '04

26 May '04

Hello All, I am using twisted in a distributed app, and a portion of the system is in Java. This may be a little off topic, but is there a package for Java that provides any of: - reactors - deferred - Protocol Objects like twisted You get used to a paradigm, and would like to stay with it as you move between languages :-) Thanks, Mike ---------------------------------------------------------------- Michael Schneider Senior Software Engineering Consultant UGS PLM Solutions - an EDS Company "The Greatest Performance Improvement Is the transitioning from a non-working state to the working state"

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[Twisted-Python] Newbie question about writing a client
by Anuj Seth 25 May '04

25 May '04

Hi, The echo client in doc/examples sends a hardcoded string from the call back "connectionMade". How can i change it to send any string produced by some other source ? For e.g., if i want to let the user enter some string and then send it to the echo server and then print the result back. Thanks for any pointers, Anuj. ------------------------------------------------------------------------------------- The information contained in this message is proprietary of Amdocs, protected from disclosure, and may be privileged. The information is intended to be conveyed only to the designated recipient(s) of the message. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, use, distribution or copying of this communication is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. ---------------------------------------------------------

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[Twisted-Python] *bsd buildbots, thanks to win32 buildbot people
by Itamar Shtull-Trauring 25 May '04

25 May '04

Who runs these? and could you please install subversion? Many thanks to "bear" and Cory for getting win32 buildbot going, and to Pavel and Cory for fixing Win32 tests. -- Itamar Shtull-Trauring http://itamarst.org

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[Twisted-Python] Nevow and twisted.enterprise and deferreds
by Alexander May 25 May '04

25 May '04

I am using nevow and twisted enterprise and have a situation like this: dbPool = adbapi.ConnectionPool('myDB') ... class MyPage(rend.Page): ... def data_mydata(self, context, data): return dbPool.runQuery("select * from table") def render_myrender(self, context, data): ... Happily, and a bit unexpectedly, it worked and the page rendered correctly. My issue is if the sql statement fails for some reason the page rendering just hangs. Is there an endorsed way to capture the error and render some html from it? Right now I'd be happy to see the call stack, as I often do when an exception occurs. I traced through the call stack and found this in renderer.py def _error(failure): # FIXME: this should *definitely* do something better # doing this leaves the connection hanging, but it's better # than nothing. print "FAILURE !",failure It looks like the errback is just set to _error. I don't know if there is a way to work around this. I attempted a few things with my own errbacks to no avail. I'm sure much of this is due to my less than perfect understanding of deferreds, and my current bleary eyed state. I could have sworn that I read something about defereds and nevow, but I can't seem to find it anymore. Any help is appreciated. Thanks, Alex PS: I'm using nevow 0.1 and twisted 1.2.

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[Twisted-Python] Two fixes
by Bertrand Croq 25 May '04

25 May '04

Hi, I am currently using Twisted to write a web site, and I wanted the site to be able to download updates from its subversion repository. Doing this, I found a bug: HTTPFactory.log does not check for a logFile attribute before using it Here is a patch that fixes the problem Index: protocols/http.py =================================================================== --- protocols/http.py (revision 10776) +++ protocols/http.py (working copy) @@ -1120,13 +1120,14 @@ def log(self, request): """Log a request's result to the logfile, by default in combined log format.""" - line = '%s - - %s "%s" %d %s "%s" "%s"\n' % ( - request.getClientIP(), - # request.getUser() or "-", # the remote user is almost never important - _logDateTime, - '%s %s %s' % (request.method, request.uri, request.clientproto), - request.code, - request.sentLength or "-", - request.getHeader("referer") or "-", - request.getHeader("user-agent") or "-") - self.logFile.write(line) + if hasattr(self, "logFile"): + line = '%s - - %s "%s" %d %s "%s" "%s"\n' % ( + request.getClientIP(), + # request.getUser() or "-", # the remote user is almost never important + _logDateTime, + '%s %s %s' % (request.method, request.uri, request.clientproto), + request.code, + request.sentLength or "-", + request.getHeader("referer") or "-", + request.getHeader("user-agent") or "-") + self.logFile.write(line) -- Bertrand Croq FreesKop - Avenue Robert Schuman - 35170 BRUZ - France http://www.freeskop.com/

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[Twisted-Python] example stdin handling client that supports readline?
by Ellers 25 May '04

25 May '04

Dear All, I'd like to write a command-line shell-like interface to an in-house database service we have. The DB service provides a socket-based API with messages like 0001-SQL-select * from customer| (where | is a 0x00 char) The server responds with messages likt 0001-SQL-name|age|otherfields||Fred|23|etc I've got the basics going OK. And in a separate script I've got a basic shell-like program going, complete with readline support. It looks a bit like: mysh$ select * from customer [would send select statement now] mysh$ etc Question: how do I integrate stdin or command-driven input into the client code? That is, because the server reactor object has control of the process, I don't see how I get read input from stdin? I notice that there is a class twisted.internet.stdio.StandardIO that provides a file descriptor wrapper around stdin etc. This looks good, but I'm not sure how to connect this with the cool readline functionality, which seems to block and take care of all handling of stdin? Is there an example of this sort of script out there? I'm *sure* this sort of thing has been done 100 times before! Thanks for any tips :) Ellers

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Twisted May 2004