Mailman 3 February 2003 - Twisted

[Twisted-Python] introductory questions for twisted.web.woven
by Alex Li 28 Feb '03

28 Feb '03

Hi Twisted, I am a newbie trying to learn the twisted.web.woven framework. After reading the docs I am still confused. Any answers or pointers would be greatly appreciated. 1. How to process a form? I tried the wovenquotes example but got confused (ex: the form used in the example has no method and action attribute in the <form> tag)? What is the class to use? (I think it is related to the twisted.web.woven.input module, but couldn't really see how...) 2. How to get the querystring? This is similar to the above question, but it can be used without form. Let's say I simply want to have a dynamic link like this: <a href="http://destination/page.rpy?src=http://come/from/here"> How to get the arguments and values after the "?" ? 3. In the twisted.web.resource.Resource class, what is an Entity? what is a Name? What is a Child (another Resource?) It would be nice if the answer can be provide is a simple example (not too abstract)? 4. So for serving files in the file system, we use twisted.web.static.File. For serving dynamically generated pages, we can use twisted.web.woven.page.Page? 5. Any examples or docs that you think I should read (beside the one listed in twistedmatrix.com website)? Thanks in advance, Alex __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - forms, calculators, tips, more http://taxes.yahoo.com/

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[Twisted-Python] Fixes for windows installer
by Thomas Heller 28 Feb '03

28 Feb '03

Dear twisted developers, here are my patches against current twisted CVS which make the bdist_wininst installer work correctly, tested on win98 and WinXP, built Python2.3 and Python 2.2 (although the latter requires a newer distutils version which supports the postinstall script). Apart from fixing this stuff so that it works for me, I made some additional changes: 1. win32all is no longer required for the postinstall script, because bdist_wininst has builtin support to create shortcuts. So I removed the warning message from the first screen. 2. The icons are no longer installed in a "Twisted 1.0.4alpha1" entry in the start menu, the Python version is also required here (because twisted can be installed separately for multiple Python versions on the same machine). The entry now looks like this: "Twisted 1.0.4alpha1 (Python 2.2)" I hereby assign the copyright for this stuff to the Twisted Matrix Labs, because I would prefer to patch this stuff only once. Is this sufficient for someone to check this in (after discussion, maybe)? Thomas

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[Twisted-Python] reactor.run() or application.save()+run?
by Mario Ruggier 28 Feb '03

28 Feb '03

Hi, trying to turn the little Resources example (below) into an application (replacing use of reactor with application), so that I can save it as an application, when i call "twistd -f pargs-webapp.tap", I get the following error : Failed to load application: <twisted.persisted.styles.Ephemeral instance at 0x3ad330> is not safe for unpickling If I do not call save() but just run(), the application runs correctly... Any ideas? mario ### from twisted.web.resource import Resource #from twisted.internet import reactor from twisted.internet import app from twisted.web.server import Site from twisted.web.static import File from PathArgs import PathArgs class DynamicRequest(Resource): def isLeaf(self): return false def render(self, req): req.setHeader('Content-type','text/plain') resp = 'uri: %s \nargs: %s\npathargs: %s\n' return resp % ( req.uri, req.args, req.pathargs ) ### def run(): root = PathArgs(splitOnComma=1) root.putChild("dynamic", DynamicRequest()) root.putChild("static",MyFile(".")) site = Site(root) #reactor.listenTCP(8081,site) #reactor.run() application = app.Application('webapp') application.listenTCP(8081,site) #application.run() application.save('pargs') ### if __name__ == '__main__': run() ###

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[Twisted-Python] Serving a binary files from disk, outside folders for static content
by Thomas Weholt 27 Feb '03

27 Feb '03

I need to serve a binary file from disk, not available in the normal folder for static content. In my code so far I've done something like this in the render-method : request.setContentType( .... content-type set based on extension of file to serve ) f = open(somefile) while 1: d = f.read(2048) # what's the correct size to read if not d: break request.write(d) request.finish() return It seem to return the data OK, it's visible in the browser, but exceptions are raised in the server. How do I close this connection the right way? Should this be used with deferred or something like that? The files can be huge in size. PS! From recent postings in this list is seems as if Twisted doesn't support compression of content, using gzip etc. Is this true? This would speed up things considerably. I implemented this in my previous webserver-project using BaseHTTPServer and on big files the increase in speed was impressive. Compressing HTML/Plain text/XML etc., just files known to be based in plain text, would be a great start. Best regards, Thomas Weholt

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[Twisted-Python] Traceback in windows installer
by Thomas Heller 27 Feb '03

27 Feb '03

I get a traceback when runing the 1.0.3 windows installer. Anyone else seeing this, or is it a problem on my side? Thomas Traceback (most recent call last): File "C:\Python22\Scripts\twisted_postinstall.py", line 25, in ? from twisted.python.shortcut import Shortcut File "C:\Python22\Lib\site-packages\twisted\python\shortcut.py", line 7, in ? from win32com.shell import shell File "C:\Python22\lib\site-packages\win32com\__init__.py", line 95, in ? SetupEnvironment() File "C:\Python22\lib\site-packages\win32com\__init__.py", line 32, in SetupEnvironment __path__.append( win32api.RegQueryValue(key, "Extensions" )) TypeError: this constructor takes no arguments *** run_installscript: internal error 0xFFFFFFFF ***

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Re: [Twisted-Python] SMTP client patch
by Anders Hammarquist 27 Feb '03

27 Feb '03

In a message of Thu, 20 Feb 2003 16:14:31 CST, Glyph Lefkowitz writes: >I had a look at this patch with Itamar today. We like where you're >going, but here are a few issues: > >1. it's not backwards compatible. DocmaServer uses its own sendEmail, >which depends on the sentEmail callback's signature. Yes, I know. The changes were needed to be able to get complete status for the message delivery. With the old code there was no way to find out what happend to failed recipient addresses. I suppose I could add logic to try and detect an old-style sentEmail. >I personally would like to see Twisted's sendEmail deprecated and >replaced with an admonishment to use the 'email' module ;), so it would >be nice if you could re-implement sendEmail in terms of your MIME-less >'sendmail' function. As in using sendmail plus the email module? Sure, will do. >2. Those change to LineReceiver made no sense to us. Care to explain? Somewhere in the docs I read that returning (as opposed to raising) an exception will land you in Factory.clientConnectionFailed with that exception (wrapped in a failure). However, LineReceiver didn't propagate the returned exceptions up to Protocol, so it didn't work without those changes. smtpConnectionFailed and smtpTransferFailed uses this. >3. What's up with the SMTP logger? and logging every line in the >client? This is duplicated generic code, and should probably be >refactored into someplace more appropriate, like twisted.python.log. I agree that it may be useful elsewhere (though expect it's use will be rather limited). The purpose keeping the log is for generating bounce messages (i.e. as sendmail says: ... while talking to foo.bar.org.: >>> RCPT To:<spam(a)foo.bar.org> <<< 550 User unknown >>> RCPT To:<eggs(a)foo.bar.org> <<< 450 Insufficient disk space ). My first look at t.p.log suggested not using it, since it dealt mostly with syslog()-like logging. I'll have another look to see if it fits with those logging functions, else I'll just rename it to something more generic and let it live in t.p.log. /Anders

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[Twisted-Python] minor patch to twisted.html.web
by Clark C. Evans 27 Feb '03

27 Feb '03

When calling escape, this function seems to assume that the object being called is a string; although a user program could do this, an explict conversion here is more generous with the input arguments. --- html.py.orig Wed Feb 26 23:17:00 2003 +++ html.py Wed Feb 26 23:17:39 2003 @@ -36,6 +36,7 @@ def escape(text): "Escape a few HTML special chars with HTML entities." + text = str(text) for s, h in [('&', '&'), #order is important ('<', '<'), ('>', '>'),

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[Twisted-Python] Twisted Resources / PathArgs
by Clark C. Evans 27 Feb '03

27 Feb '03

On Tue, Feb 25, 2003 at 01:20:34PM -0600, Ian Bicking wrote: | > flexible. I say this beacuse I was able to do path variables | > out-of-the-box (2 hours) with this tool; in Webware I've been | > maintaining a patch for over a year, and this patch isn't ideal. | | Can you give a pointer to that? I'm interesting in changing how paths | are parsed in Webware, but I've never felt confident The Twisted model has the notion of a resource. Let's start with a simple working example: from twisted.web.resource import Resource from twisted.internet import reactor from twisted.web.server import Site from twisted.web.static import File class DynamicRequest(Resource): def isLeaf(self): return true def render(self, req): req.content_type = 'text/plain' return "uri: %s" % req.uri def run(): root = Resource() root.putChild("dynamic", DynamicRequest()) root.putChild("static",File(".")) site = Site(root) reactor.listenTCP(8081,site) reactor.run() The interface of resource is a collection, and has a getChild( pathsegment ) method is called for every segment in the path. So, /foo/bar/baz is somewhat equivalent to the following: site.resource.getChild('foo').getChild('bar').getChild('baz') Twisted accomplishes this magic in a "private" function called getChildForRequest which iterates over each path segment. For the current resource it first checks a mapping to see if any static configured children (putChild) exist, and if a static child isn't found, it calls getChild() to find the next child in order. Of course, the iteration stops when isLeaf() is true. Twisted comes with many built in Resources, including a really nice one for doing redirects (Redirect) and dynamically serving up a file system (File). It also seems to have ones for handling virtual hosts, and sessions. Very cool. For more detail... http://www.twistedmatrix.com/documents/TwistedDocs/current/api/ public/twisted.web.resource.Resource.html On Tue, Feb 25, 2003 at 08:18:25PM +0100, Paul Jongsma wrote: | Last night I was playing with Twisted to get some insight into it, | one of the things which I tried to figure out was how to do | path variables. | | Would you mind sharing your solution with me? The docs on | Twisted are sparse and I haven't been able to figure it out | yet.. Assume that your path is something like... /key:val/another:val/<servlet> At any point in the tree, you should be able to add the following "resource" which will eat all items in the path having a colon. class PathArgs(Resource): def getChild(self,path,request): if not(hasattr(request,'pathargs')): request.pathargs = {} pair = path.split(':') if 2 == len(pair): request.pathargs[pair[0]] = pair[1] return self return Resource.getChild(self,path,request) To try it out, replace "root = Resource()" with "root = PathArgs()" in the code above. Note, you should be able to use this resource anywhere in the tree... I'm completely astonished with the power/simplicity of this mechanism. Serious Kudos to the brain who discovered it... that such a small amount of code can add a "pathargs" attribute to each request in a way that is completely pluggable is just spectacular! Clark

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[Twisted-Python] Woven and others
by Julio Rommi Oña Miranda 27 Feb '03

27 Feb '03

Hi everyone, I was reading the source of woven (with the hwlp of Issues) what a pice of code!!! I like the idea, but I was asking me why woven should spend all it's power only with web, it would be nice if it work with some GUI interface. I mean, using all the VCM structure to work with them (TK, wx, etc.) as a interface building. This should not be too hard because the only the View component component should be modified. Does Twisted has something like this? a generic woven? Regards. -- Julio

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[Twisted-Python] distant learning, video conference
by tch 26 Feb '03

26 Feb '03

Hi,All: Is twistedpython a framework suitable for developing distant learning and/or video conference application? Regards, Tsuangchi Huang

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