Mailman 3 November 2005 - Twisted-web

Test
by Philippe Lafoucrière 05 Aug '21

05 Aug '21

Hi all just a test

3 2

web2 response.setCookie and request.getCookie shortcuts?
by Clark C. Evans 21 Jan '06

21 Jan '06

I'm still having fun with web2, it is such a huge improvment over twisted.web and I'm absolutely thrilled with it. However, I have a few suggestions: 1. It would be supreme if render() and locateChild() just provided me the Request object; the incantation to ctx.locate() seems a tedious an unnecessary step. 2. I would love a request.getCookie('cookie-name') and response.setCookie('cookie-name','cookie-value', path = '/') helper; that adds the given cookie to the current list. 3. Make the 'path' in the Cookie constructor and setCookie default to '/'. Almost all of the time you want your cookies to be site-wide; adding path = '/' to each request adds a point of failure that makes the system less usable. Kind Regards, Clark P.S. Following is sample cookie code that works with web2 --- from twisted.internet import reactor, defer from twisted.web2 import server, http, resource, channel, iweb from twisted.web2.http_headers import Cookie class Toplevel(resource.Resource): addSlash = True def render(self, ctx): request = ctx.locate(iweb.IRequest) found = False for cookie in request.headers.getHeader('cookie',[]): if cookie.name == 'testing': print "found", cookie.value found = True response = http.Response(stream="Hello monkey!") if not found: print "not-found" cookie = Cookie("testing","womble",path="/") response.headers.setHeader('Set-Cookie',(cookie,)) return response # Standard twisted application Boilerplate from twisted.application import service, strports application = service.Application("demoserver") site = server.Site(Toplevel()) s = strports.service('tcp:8080', channel.HTTPFactory(site)) s.setServiceParent(application)

6 12

Error output for bad deferred method signatures?
by Lenny G Arbage 02 Dec '05

02 Dec '05

I'm curious why errors aren't reported when deferreds are fired if the deferred method has a bad signature. For example, if the following is run: import httplib, sys from twisted.web import client from twisted.internet import reactor, threads, defer from twisted.protocols import http from twisted.python import failure class getYahoo(object): def __init__(self): factory = client.HTTPClientFactory("http://www.yahoo.com") reactor.connectTCP("www.yahoo.com",80,factory) factory.deferred.addCallback(self._gotResponse, factory) factory.deferred.addErrback(self._errSendReq, factory) self.deferred = factory.deferred def _gotResponse(self, resp, factory): print "yeah!" print resp def _errSendReq(self, err, factory): print "shucks!" print err def sendRequest(): return getYahoo().deferred if __name__ == '__main__': def test(msg): print msg print respOrErr d = sendRequest() d.addCallback(test, "success") d.addErrback(test, "failure") reactor.run() The deferred _gotResponse() and _errSendReq() fire perfectly, but the test() function in __main__ is not called for "success" or "failure". This is expected as the signature is wrong -- it should be 'test(respOrErr, msg)'. What isn't clear [to me] is why this doesn't produce an error upon firing the deferred, but instead produces an error when the reactor shuts down [via ctrl-c], which could be hours later. I have an instance of this that is more severe, where the error output is *never* produced (maybe because of threading?). Is this the expected behavior, or am I doing something atrocious to produce it? Thanks, Lenny __________________________________ Yahoo! Music Unlimited Access over 1 million songs. Try it free. http://music.yahoo.com/unlimited/

2 3

Nevow Athena LiveFragment without allowedMethods
by Paul Reznicek 01 Dec '05

01 Dec '05

Hi JP & co., I've just started playing with current ATHENA - very nice !!! Is there any deeper security reason to use the "allowedMethods" mapping additionally to the simple fact, that a fragment implements a method only if it is necessary? If not, please consider to apply attached patch. It makes the code and use of it a little bit simpler. Thanks for your great work, best regards, Paul Reznicek Index: nevow/athena.py =================================================================== --- nevow/athena.py (Revision 3368) +++ nevow/athena.py (Arbeitskopie) @@ -407,20 +407,18 @@ <form onsubmit="Nevow.Athena.refByDOM(this).callRemote('foo', bar); return false;"> - By default, only methods named in the C{allowedMethods} mapping - may be invoked by the client. """ - allowedMethods = {} - def rend(self, context, data): myID = self.page.addLocalObject(self) context.fillSlots('nevow:athena_id', myID) return super(LiveFragment, self).rend(context, data) def locateMethod(self, ctx, methodName): - if methodName in self.allowedMethods: - return getattr(self, methodName) + if not methodName.startswith('_'): + method = getattr(self, methodName, None) + if method: + return method raise AttributeError(methodName) Index: examples/athenademo/athenatest.py =================================================================== --- examples/athenademo/athenatest.py (Revision 3368) +++ examples/athenademo/athenatest.py (Arbeitskopie) @@ -23,7 +23,6 @@ tags.form(action='#', onsubmit='return test(test_ClientToServerArgumentSerialization(this));')[ tags.input(type='submit', value='Test Client To Server Argument Serialization')]]) - allowedMethods = {'test': True} def test(self, i, f, s, l, d): self.assertEquals(i, 1) self.assertEquals(f, 1.5) @@ -65,7 +64,6 @@ tags.form(action='#', onsubmit='return test(test_ClientToServerResultSerialization(this));')[ tags.input(type='submit', value='Test Client To Server Result Serialization')]]) - allowedMethods = {'test': True} def test(self, i, f, s, l, d): return (i, f, s, l, d) @@ -104,7 +102,6 @@ tags.input(type='submit', value='Test Client To Server Asynchronous Exception Result')]]) - allowedMethods = {'testSync': True, 'testAsync': True} def testSync(self, s): raise Exception(s) @@ -135,7 +132,6 @@ tags.form(action='#', onsubmit='return test(test_ServerToClientArgumentSerialization(this));')[ tags.input(type='submit', value='Test Server To Client Argument Serialization')]]) - allowedMethods = {'test': True} def test(self): return self.page.callRemote('test_Reverse_ServerToClientArgumentSerialization', 1, 1.5, u'hello', {u'world': u'value'}); @@ -159,7 +155,6 @@ tags.form(action='#', onsubmit='return test(test_ServerToClientResultSerialization(this));')[ tags.input(type='submit', value='Test Server To Client Result Serialization')]]) - allowedMethods = {'test': True} def test(self): def cbResults(result): self.assertEquals(result[0], 1) Index: examples/athenademo/typeahead.py =================================================================== --- examples/athenademo/typeahead.py (Revision 3368) +++ examples/athenademo/typeahead.py (Arbeitskopie) @@ -20,7 +20,6 @@ class TypeAheadFieldFragment(athena.LiveFragment): docFactory = loaders.stan(T.input(type="text", id="typehere", **athena.liveFragmentID)) - allowedMethods = { 'loadDescription' : True } def loadDescription(self, typed): if typed == '': Index: examples/livefragments/livefrag.py =================================================================== --- examples/livefragments/livefrag.py (Revision 3368) +++ examples/livefragments/livefrag.py (Arbeitskopie) @@ -40,11 +40,10 @@ def __init__(self, label, *a, **kw): super(CooperativeFrag, self).__init__(*a, **kw) - self.allowedMethods = {label: True} setattr(self, label, lambda: unicode(label)) def render_submit(self, ctx, data): - return "submitIt(this, '%s'); return false;" % (self.allowedMethods.keys()[0],) + return "submitIt(this, 'label'); return false;" class Root(rend.Page): def child_(self, ctx):

2 3

Sessions and Authentication for Web2
by Clark C. Evans 30 Nov '05

30 Nov '05

Hello. I am in the middle of porting my application(s) to web2, and it seems that general authentication and session handling is not yet implemented. My requirement is rather simple: 1. When the user connects to my system (via HTTPS), I check for a cookie that indicates their server-side session. If they have a session active, I touch() the session so that the expiration date is pushed out. 2. If the cookie does not exist, or the session has expired, then I send them through one of 3 authentication mechanisms depending on either their IP, a query argument, or what resource they are trying to access. a) If they are coming from a YALE IP address and have not explicitly asked for HTTP Digest authentication, I use the CAS authentication mechanism: http://www.yale.edu/tp/auth/cas20.html b) Else, if they are viewing a limited "semi-restricted" set of resources, I use another custom challenge-response mechanism that is similar to CAS (but slightly different) c) Otherwise, I use HTTP Digest Authenitication. All of these methods require that the request be cut short, and either a 401 is returned, or a HTTP Redirect (for CAS). 3. Once I have an authorized user; I create a session for them, and set a 20 minute timeout. I might have multiple requests active for the same session. Once I have a session, I need a few things: 1. A way to getSession() from a given request; in particular, most resource authorization is based on the user's identity. 2. Request specific storage of temporary working data so that requests in-progress can accumulate results before the response is generated. 3. Session specific storage, so that information about the user's context can be maintained. This needs to be synronized with a database server since the Session may be shared across multiple servers. 4. A JobQueue for that particular Session. Many queries take a long time to run; and incremental results and/or failure notices need to be managed between each request. Of these requirements, #1 is most important, and #4 is a wish-list item for the next version of my application. We had a chat on IRC today, and a few random notes/ideas emerged: a) There was a strong preference to keep Session and Authentication completely separate. Currently Nevow's Guard mixes the two and thus is overly complicated and non-modular. Nevow also uses Componentized, which is depreciated (in favor of... ?) http://divmod.org/trac/browser/trunk/Nevow/nevow/guard.py http://divmod.org/trac/browser/import/Nevow/sandbox/mg/guarded/guard.py b) Besides Nevow's GuardSession, there are a few other session implementations besides the older twisted.web implementation. A requtil.py in web2 seems to be a straight-forward port of tw.web's sessions. Quixote also has a session manager, http://quixote.idyll.org/session2/ which is licensed to steal. c) Exarkun expressed a strong (ok, mandatory) preference for the use of tw.cred in any Authentication solution. However, it was noted that tw.cred does not allow for challenge-response authentication mechanisms (which all of mine are). Specific examples were noted: twisted.protocols.sip, SASL, OTP d) There was talk that the Session manager should actually be a filter on the Response object; so that it can rewite paths and/or inject cookies as needed before the response is sent. This seems a bit complicated, no? e) I can probalby help in some ways, but I'm not a Twisted expert. I could continue to collect requirements and post; but I have short term deadlines (as usual). If you wish I could put two files in twisted.web2, marked 'experimental': session.py This would contain session manager, how ever it is eventually implemented. guard.py This would contain the gule to link tw.cred to web2. I prefer an iterative; implement the simplest solution first, and then grow it as needed approach (with clear marks on instability). I wouldn't mind owning these two files and collecting feedback, etc. Anyway, thanks for listening. Any thoughts as to how to best proceed would be very welcome. Kind Regards, Clark P.S. For now, I'm hacking my own session and auth code. There is a requtil.py in web2 which is a stab at sessions, and both David Reid and I have HTTP Auth code in our sandbox.

7 15

Concurrency in a twisted.web application
by Ananda Tallur 29 Nov '05

29 Nov '05

Dear twisted.web developpers and users, I have written a twisted application for viewing and exporting movies. These movies are in a format specific to my company. I use : twisted 2.1.0, twisted.web 0.5.0, and nevow 0.5.0 (all html templates are written using nevow). In this web application, there is a feature for exporting a movie file into mpeg, and sending it to the client web browser (file download). This feature is handled by a resource object which is a subclass of static.File. Exporting a movie into mpeg implies : -> opening the original video file -> doing the conversion (which can take as long as 1 minute or more) -> sending the resulting mpeg file to the browser (file download) The problem is that while the twisted web application is working handling the export request, the twisted web server is not responsive to any other HTTP request, as long as the video conversion and file transfer is not finished. I would like to know if there is a standard or recommanded way of setting up concurrency into a twisted.web application. And also if there is a sample program available somewhere. I would like my web application to be still responsive to other HTTP requests while : -> file conversion to mpeg is being processing -> mpeg file is being transfered to the client browser (which is handled by a static.File subclass resource) Thank you very much for all your answers. I appreciate very much working with twisted.web and interested to get more insight into the way twisted core handles requests. Anand

3 3

About Authentication/Membership
by QnA 29 Nov '05

29 Nov '05

Hi, I am new to Twisted project and my job is to write a few web-pages under twisted framework. I want to ask if Twisted provide a user authentication and session library just like PHP or JSP?? Or may anyone can give me some idea or articles I should read? Thank you very much for all kindly help. Regards, QnA

1 0

Some questions regarding nevow.athena
by Johannes Beigel 28 Nov '05

28 Nov '05

Hi. We are currently using Twisted+Nevow to build web frontends. There's some AJAX stuff involved and we are using several JavaScript and Python packages and mostly custom code for this. With the new Nevow versions a restructuring of LiveEvil/Livepage code to the new athena package has begun. I looked at it and it looks very promising, especially the way it integrates into existing Nevow code and templates. Is there some API documentation/example code available (some more than in the SVN tree)? The code states that the API could be rather unstable. Would you rather recommend to wait for a little more mature athena before using it in production code? -jojo

1 0

Json breakage
by Stephen Thorne 28 Nov '05

28 Nov '05

Hi, Cory noted that json is broken, jp told me about it, I looked at it and hated regexps. This patch *seems* to work, and passes the tests. The tests are insubstantial and my grasp of python's regular expressions is crap, so I'd like someone to review this patch before I commit it. Stephen.

1 0

Serving different resource types from the same directory
by Olivier Laurent 27 Nov '05

27 Nov '05

On dim, 27 nov 2005, at 16:18, oli wrote: I'm trying to serve 2 different kind of resources from the same directory. I can, with no problem, serve one kind or the other but not the two resource types at the same time. Examples abounds on the web on how to serve one kind of resources from subdirectory /foo and another kind from subdirectory /bar. But no example on how to serve different kind of resources from the same directory. Here is how I tried: # [...] PATH = '/var/www/' pt_resource = static.File(PATH) pt_resource.processors = { '.pt' : PTResource } pt_resource.indexNames = [ 'index' + '.pt' ] rst_resource = static.File( PATH ) rst_resource.processors = { '.rst' : RSTResource } rst_resource.indexNames = [ 'index' + '.rst' ] #root = Resource() # I tried this too root = static.File(PATH) root.putChild(PATH, pt_resource) root.putChild(PATH, rst_resource) reactor.listenTCP( 80, server.Site( root ) ) reactor.run( ) # this is the end What's wrong ? What did I forget ? Is it possible ? Thank you. -- Olivier Laurent

3 3

Dynamical generated slots
by Johann Siegele 25 Nov '05

25 Nov '05

Hello, im looking for a possibility to generate Slots for a livepage dynamical. my code for the livepage looks like this, it works fine, but i can not update any of the slots! def render_mytable(self, ctx, data): mydetail=[] for i in range(1,15): mydetail.append([T.td [T.slot('test'+str(i), "default")]]) if i % 3 is 0: mydetail.append([T.tr[T.td['-test-']]],) return ctx.tag[mydetail] template: <table nevow:render="mytable" name="mytabletest"/> it should be possible that the user can change the text in the row n and colume x. this do not work: client.set('test1', text) i think the problem is, that the slots are not hardcoded. is there a other possibility. thank you very much!

2 1

resource constructor called on every request
by Remi Cool 24 Nov '05

24 Nov '05

Hello, I don't know if this is a 'normal' twisted/nevow operation procedure, but my base resources' __init__ is called on every request. Since a putChild for XMLRPC is setup in this __init__ (which includes a lot of code), I'm worried about execess overhead. Is there a way to include the XMLRPC section in a way that it get's initialized only once? I need the XMLRPC functionality on the same port as the HTTP(S) for firewall reasons. Something else ... in locateChild -> if segments[0] == '': # If the server is looking for the root page segments will be ('',) # then renderHTTP will be called on self When I return self, () a max recursion error is the result ... what should I return here? -- CODE -- class httpResource(rend.Page): addSlash = True def __init__(self, service): rend.Page.__init__(self) self.service = service self.putChild('RPC2', protocols.xmlrpc(self.service)) rt = static.File("www") rt.ignoreExt(".rpy") rt.processors = {'.rpy': script.ResourceScript, '.php': phpScript} rt.indexNames.append('index.php') self.putChild('www', rt) def locateChild(self, ctx, segments): """""" if segments[0] == '': # If the server is looking for the root page segments will be ('',) # then renderHTTP will be called on self return None, () elif segments[0] in ctx.tag.children.keys(): return ctx.tag.children[segments[0]], segments[1:] else: return None, () def renderHTTP(self, ctx): """""" if self == ctx: return "<html><body>renderHTTP: ROOT</body></html>" return ctx.tag components.registerAdapter(httpResource, IowwService, inevow.IResource)

1 1

How to use twistd on Windows to run a simple webserver
by Keith.Gunderson＠act.org 22 Nov '05

22 Nov '05

I've finally found a good reason to delve into twisted at my job. I've been keeping up with your progress over the past few years, but now I can't seem to get the simplest of webapps to run. (I've read all the docs and blogs that I can get my eyes on.) The basics....No IRC during business hours, Win2000, python2.4, latest TwistedSumo plus TwistedWeb2 reinstalled for good measure. I want to run the 'Simple application' described the twisted.web2 introduction. (pasted below.) Twistd.py has syslog issues for me. My 'twistdWithSyslogRemoved.py' does nothing but release an inaudible chirp. (As does _twistd.py .) What additional hints can you give me? I have delusions of nevow, mantissa, and glory in my future. But one step at a time. Many, many thanks. (from intro.txt) from twisted.web2 import server, http, resource class Toplevel(resource.Resource): addSlash = True def render(self, ctx): return http.Response(stream="Hello monkey!") site = server.Site(Toplevel()) # Standard twisted application Boilerplate from twisted.application import service, strports application = service.Application("demoserver") s = strports.service('tcp:8080', http.HTTPFactory(site)) s.setServiceParent(application) Save this program as ``example1.py``, and then run it via ``twistd -ny example1.py``. ``twistd`` is the Twisted runner; it knows how to execute applications by looking for the magic ``application`` variable declared at top-level. You can also run your server daemonized, via ``twistd -oy example1.py``. You can then access your server via the url "http://localhost:8080/". For more deployment options, see the deployment_ chapter. Keith Gunderson Performance Test Analyst IT Audit and Reporting ACT, Inc. 301 ACT Drive Iowa City, IA 52245 (319) 337-1548 Voice (319) 337-1766 Fax

3 3

Re: [Twisted-web] How to use twistd on Windows to run a simple webserver
by Keith.Gunderson＠act.org 22 Nov '05

22 Nov '05

Thats the ticket. Very nice. The shortcut was hidden in a menu under a button labeled Start :( Here's the details... C:\WINNT\system32\CMD.EXE /k C:\SOMEWHERE\python24\lib\site-packages\twiste d\twistenv.bat C:\SOMEWHERE\python24\scripts Keith Gunderson Jean-Paul Calderone <exarkun(a)divmod.com> To: twisted-web(a)twistedmatrix.com Sent by: cc: twisted-web-bounces@twiste Subject: Re: [Twisted-web] How to use twistd on Windows to run a simple webserver dmatrix.com 11/22/2005 02:03 PM Please respond to "Discussion of twisted.web, Nevow, and Woven" On Tue, 22 Nov 2005 13:52:17 -0600, keith.gunderson(a)act.org wrote: >I've finally found a good reason to delve into twisted at my job. I've >been keeping up with your progress over the past few years, but now I can't >seem to get the simplest of webapps to run. (I've read all the docs and >blogs that I can get my eyes on.) ... twisted/scripts/twistd.py is a private implementation module, it is not intended to be invoked directly. It is only used when you use twistd on POSIX. twisted/scripts/_twistw.py is also a private implementation module. It is only used when you use twistd on Windows. bin/twistd is the executable program intended to be invoked. I'm not sure how the latest Windows installer works. It used to provide a command shell (cmd.exe with the environment configured to make working with Twisted easier) from which you could run "twistd" without specifying the full location. This may still be the case. In any case, you definitely don't want to run anything in twisted/scripts/ manually. Jean-Paul _______________________________________________ Twisted-web mailing list Twisted-web(a)twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-web

1 0

Twisted Network Programming Essentials
by Stephen Nightingale 22 Nov '05

22 Nov '05

Fine Book. I'm working through the examples. Hit a problem with the wordcountproxy.py example, under the explanation of HTTP Proxy Servers, on page 62.. As this __might__ be an issue with Twisted itself, I'm cross-posting here as well as back to O'Reilly errata. The issue is that the: 'reactor.listenTCP(WEB_PORT, WebReportFactory(counter))' call precipitates an error message in _getfullpathname in Lib/ntpath.py, called from web/http.py, and the error is: 'TypeError: coercing to Unicode: need string or buffer, WordCounter found' The full traceback is given below. N.B. I'm using Python 2.4.1 on Win XP. I wonder if anyone else has come across this issue? Any insights gratefully received, Regards, Stephen Nightingale. 2005/11/21 23:20 GMT Standard Time [-] Log opened. 2005/11/21 23:20 GMT Standard Time [-] __main__.WordCountProxyFactory starting on 8001 2005/11/21 23:20 GMT Standard Time [-] Starting factory <__main__.WordCountProxyFactory instance at 0x00F03878> 2005/11/21 23:20 GMT Standard Time [-] Traceback (most recent call last): 2005/11/21 23:20 GMT Standard Time [-] File "wordcountproxy.py", line 137, in ? 2005/11/21 23:20 GMT Standard Time [-] reactor.listenTCP(WEB_PORT, WebReportFactory(counter)) 2005/11/21 23:20 GMT Standard Time [-] File "D:\Python\Lib\site-packages\twisted\web\http.py", line 1086, in __init__ 2005/11/21 23:20 GMT Standard Time [-] logPath = os.path.abspath(logPath) 2005/11/21 23:20 GMT Standard Time [-] File "d:\Python\lib\ntpath.py", line 500, in abspath 2005/11/21 23:20 GMT Standard Time [-] path = _getfullpathname(path) 2005/11/21 23:20 GMT Standard Time [-] TypeError: coercing to Unicode: need string or buffer, WordCounter found --------------------------------- To help you stay safe and secure online, we've developed the all new Yahoo! Security Centre.

2 3

LivePage cannot append rows to tables?
by Mike Pelletier 22 Nov '05

22 Nov '05

I'm at my wit's end! Have mercy on a clueless JS user and examine the attached page. The problem it illustates is one I am having with livepage.js's nevow_appendNode function. I am finding that whenever I attempt to append a row to a table (or to a tbody, or for that matter to anything else) the HTML is silently stripped out and my node is added as a single #TEXT node. However, appending a DIV works fine, even when technically illegal; a DIV node containing the #TEXT is added. The attachment includes a copy'n'pasted version of nevow_appendNode. The only modification I have made to it is to add an alert() which demonstrates the precise point of failure; assigning "what" to "newspan.innerHTML". Note that the <div> tags are unmolested, but the <tr> and <td> tags are stripped. I get the same behaviour from FF and IE, while Konq just barfs with a DOM exception 7. I simply don't know how to chase this one down any further. I hope someone will tell me I'm a moron and point out what I've done wrong, but I think the solution is going to require a change to nevow_appendNode. Thanks muchly, Mike.

2 3

State and web2 (or, how to not follow REST)
by Clark C. Evans 21 Nov '05

21 Nov '05

This is an attempt to summarize a conversation I had /w glyph on #twisted.web earlier today. I've attached the IRC log. The basic problem discussed was how to manage server-side state; which in particular includes sessions and authentication. Stateful servers cause serious problems with scalability and with bug hunting. Glyph is adamant that getSession() as it currently works (by raising a redirect exception if the session does not already exist) must be fixed. I absolutely agree with this; as it currently stands the top-level resource must always ask for a Session object to avoid unexpected redirects down the request stream. This shouldn't be a lesson of experience; it should be built-in convention. A related issue, one to which Glyph is very concerned about, is the implicit coupling of resources during the handling of a given request. In particular, where a resource X (located at /foo) sets a variable V in the request R and then a resource Y (at /foo/bar) comes to depend upon this variable V. If this coupling is not made explicit and checked-for, then an opportunity for rather obscure bugs emerge; one where the resource Y is re-used in another context (say at /bing/bar) and still assumes that V is set. While Twisted framework cannot prevent such nonsense, it should propose an alternative mechanism, or at the very least not promote such dynamic resource dependencies. One way to make resource dependencies explicit is to require that the constructor for a child resource take an optional ancestor resource in its constructor. In this model, each user/session would in essence have its own top-level resource, and all resources which dependended upon session state would take in its constructor the parent resource. This approach has a few deficiencies: (a) there might be more than one instance of a resource Y at /foo/bar, one for each user; this is not only inefficient but makes debugging hard beause the relation of a URI onto a resource object is not a relation; (b) while leaf resources, such as a static.File object need not take a parent resource in its constructor; it forces generic Resources to have a "pass-through" parent Resource, even if it does not need state information. In the IRC conversation, I believe (and hope) this was proposed and then eventually rejected; but I'm not sure. I don't like the idea of any Resource objects in the system being user or session specific. Another alternative is to add a getSiteResource() and setSiteResource() to the Request interface. The SiteResource would then contain the top level resource "/" which reflected the user's Session and any other application specific server side state (ie, nasty persistent global-like variables which breaks REST). The SiteResource would therefore be an appliation specific object; it could, for example contain an session-id and a username property for down-stream Resource authorization. Later in the IRC chat, Glyph said he is "coming around to the fact that it's not really a resource". This is good; beacuse I don't think that this server side state is a resource by the definition of web architecture. I didn't mention it in the IRC chat, but I'm now thinking that these methods on the request object could be setState() and getState(); and that they return an arbitrary application-defined object which has all of the nastly (but unfortunately mandatory and pratical) session and request "global variables" that break REST and can cause all sorts of problems. Glyph mentioned earlier in an email that perhaps a declarative syntax could be introduced so that arbitrary Resources could advertise exactly what "state" they will access; and hence, these sorts of errors could be detected and reported more intelligently. I like this idea; it is framework support to prompt developers to put in the assertion checks that they should already be doing. It codifies a solid pratice, and this is a good thing. ;) I think that Glyph and I did have a clear agreement: all of the information on the State (in Glyph's terms SiteResource) object should be set (and perhaps made read-only?) _before_ any Resource delegation is made. We do have a slight (but very slight) semantic difference. I see the process of setting up a session and creating any server-side state as done in a IRequestHandler _before_ any IResources are called. Glyph sees this as being done "by a resource which sits at the the top level". In both models, this sort of stuff is done before your average every-day resources are processed; my model is just more explicit and allows for chaining IRequestHandlers (such as one for sessions, and another one for authentiction) before IResources are processed. I think that's about it. I just want a simple solution to this, and soon. Best, Clark

1 1

Forms - question
by Maciej Kucharz 20 Nov '05

20 Nov '05

Hello, I have a question for users of "forms" (http://forms- project.pollenation.net). I'm looking for a way to do something like this: class UserAdd(forms.ResourceMixin, rend.Page): def __init__(self, user, step=1, *a, **k): apply(forms.ResourceMixin.__init__, (self, user) + a, k) self.user = user self.step = step def form_edit(self, ctx): [...] form.addAction(submit) return form def formSubmitted(self ,ctx, form, data): print form, data return UserAdd('myuser', self.step) I want to render form, depend on "self.step" (i want have a few form steps on my site). In contruction like above on action submit i have neverending loop. thanks, for any advice PS. I simply want to have an effect like in "testformless.py" (from nevow examples): """ class NameWizard(rend.Page): docFactory = loaders.stan(tags.html[tags.h1["What is your name"], webform.renderForms()]) def bind_name(self, ctx): return [('name', annotate.String())] def name(self, name): return QuestWizard(name) class QuestWizard(rend.Page): docFactory = loaders.stan(tags.html[tags.h1["What is your quest"], webform.renderForms()]) def bind_quest(self, ctx): return [('quest', annotate.Choice(['Find the Grail', 'Get laid', 'Earn twenty bucks', 'Destroy the sun']))] def quest(self, quest): return FinalWizard((self.original, quest)) """ -- qk

1 0

TEST - ignore it!
by Maciej Kucharz 20 Nov '05

20 Nov '05

Test. -- qk

1 0

HTTP-AUTH for web2 / Kudos on web2's operation
by Clark C. Evans 20 Nov '05

20 Nov '05

Hello. I didn't see any examples of how to do HTTP Digest authentication with twisted.web2, so I updated my ancient code in the sandbox -- it was easier than I expected. Nice job with web2. http://cvs.twistedmatrix.com/cvs/sandbox/cce/digest2.py I had a few observations with my first run /w web2: 1. It would be delightful if WebContext had a request() helper method that did the appropriate adaptation to an IRequest 2. It would be excellent if locateChild was deferrable, often times you need to access a database to construct dynamically the appropriate resource. This is not a syncronous operation. 3. It would be wonderful if HTTPError took arguments that would construct an appropriate Response... it is trivial, but a nice touch if it did. Overall, web2 is looking quite nice; I'll have more feedback once my entire application is ported. Cheers, Clark

5 17

CSS - locateChild
by dsalvatore＠freesurf.fr 19 Nov '05

19 Nov '05

Hello, In the following example, without the 'locateChild' the css style sheet is rendered, but not when I try to uses locateChild. Betwise, is this a good way to refresh a page using 'return self,()' ? Thank you for your help Salvatore from twisted.application import service, internet from nevow import loaders,rend,appserver,static class Page(rend.Page): child_css = static.File('css') docFactory = loaders.xmlfile('xmlsite.xml') def render_left(self,context,data): return data def data_menu(self,context,data): return data def locateChild(self,context,data): return self,() site = appserver.NevowSite(Page("TEST")) application = service.Application('example') internet.TCPServer(8080, site).setServiceParent(application)

2 1

Problems Running Nevow standalone (no twisted)
by Michael Schneider 19 Nov '05

19 Nov '05

I was trying the config with no twisted. I updated from SVN, then tried this test, and it failed . Any suggestions? Thanks Mike --------------------------- test from nevow import flat, stan html = stan.Tag('html') print html p = stan.Tag('p') print p someStan = html[ p(style='font-family: Verdana;')[ 'Hello, ', 'world!' ] ] print flat.flatten(someStan) -------- Error --------------------------------- Traceback (most recent call last): File "C:\devTesting\learning\stan\learn1\basicHtml1.py", line 1, in ? from nevow import flat, stan File "C:\Python24\Lib\site-packages\nevow\__init__.py", line 12, in ? from nevow import compy File "C:\Python24\Lib\site-packages\nevow\compy.py", line 17, in ? from compyCompat import * AttributeError: 'module' object has no attribute 'IComponentized' -- The greatest performance improvement occurs on the transition of from the non-working state to the working state.

2 1

sending svg code from livepage
by Andreas De Stefani 18 Nov '05

18 Nov '05

Hi all, I would like to display svg which is generated on the server side, I tried to do so with nevow and livepage but i experienced some problems... i tried both sending the code embedded in a <embed> and <object > tag but none of this worked... when i use a iframe to display the svg it gets all screwed up and no graphics are shown.... i was wondering if this was related to nevow/twisted as if i just point my browser (firefox) to the file ... it works just fine! thanks for any help! Andreas

1 0

Nevow IResource trouble
by Remi Cool 18 Nov '05

18 Nov '05

Hello, after batteling with XMLRPC and getting nevow to put something on the screen, I got stuck implementing a livepage and webform example. After changing the implements to inevow.IResource in httpResource, I got a message about a missing locateChild method (is that about the same as the getChild method in a twisted web resource?) ... I've created one, but I'm not shure if it's correct. Bottomline is I can't get it to work, not from the code and not from a resource file ... what's wrong with this code? Here's my code: ----------------------------------------------------------------------------------------------- class ISimpleMethod(TypedInterface): def simple(self, name=String(description="Your name."), age=Integer(description="Your age.")): """Simple Please enter your name and age. """ class Implementation(object): implements(ISimpleMethod) def simple(self, name, age): print "Hello, %s, who is %s" % (name, age) class WebForm(rend.Page): print 'WEBFORMS:', webform.renderForms('original') docFactory = loaders.stan(tags.html[ tags.body[ tags.h1["Here is the form:"], webform.renderForms()]]) class httpResource(resource.Resource): implements(inevow.IResource) def __init__(self, service): resource.Resource.__init__(self) self.service = service ##self.putChild('RPC2', Example(self.service)) self.putChild('formtest', WebForm(Implementation())) rt = static.File("rpy") rt.ignoreExt(".rpy") rt.processors = {'.rpy': script.ResourceScript} self.putChild('rpy', rt) def render(self, request): self._clientIP = request.getClientIP() return resource.Resource.render(self, request) def render_GET(self, request): """Process HTTP GET Requests.""" print 'GET: request ->', request return '<html><body><h3>Not Implemented</h3></body></html>' def getChild(self, path, request): """This method handles http calls""" print 'getChild path:', path print 'getChild request:', request if path=="": return httpResource(self.service) else: return httpResource(self.service) def locateChild(self, ctx, segments): """""" print 'CTX:', ctx print 'SEGMENTS:', segments return self, segments components.registerAdapter(httpResource, IowwService, inevow.IResource) def main(): """""" application = service.Application('OWW', uid=1000, gid=1000) s = owwService() serviceCollection = service.IServiceCollection(application) internet.TCPServer(7080, appserver.NevowSite(s)).setServiceParent(serviceCollection) serviceCollection.startService() reactor.run() if __name__ == '__main__': main() ---------------------------------------------------------------------------- livepage.rpy ---------------------------------------------------------------------------- from nevow.livepage import handler from nevow import rend, tags, loaders def greeter(client, nodeName): client.alert("Greetings. You clicked the %s node." % nodeName) # Any string arguments after the event handler function will be evaluated # as JavaScript in the context of the web browser and results passed to the # Python event handler handler = handler(greeter, 'node.name') class Live(rend.Page): docFactory = loaders.stan( tags.html[ tags.body[ tags.ol[ tags.li(onclick=handler, name="one")["One"], tags.li(onclick=handler, name="two")["Two"], tags.li(onclick=handler, name="three")["Three"] ] ] ]) resource = Live() ------------------------------------------------------------------ testform.rpy ------------------------------------------------------------------ from formless.annotate import TypedInterface, Integer, String from nevow import rend, tags, loaders, appserver, inevow from formless import webform from zope.interface import Interface, implements class ISimpleMethod(TypedInterface): def simple(self, name=String(description="Your name."), age=Integer(description="Your age.")): """Simple Please enter your name and age. """ class Implementation(object): implements(ISimpleMethod) def simple(self, name, age): print "Hello, %s, who is %s" % (name, age) class WebForm(rend.Page): print 'WEBFORMS:', webform.renderForms('original') docFactory = loaders.stan(tags.html[ tags.body[ tags.h1["Here is the form:"], webform.renderForms()]]) resource = WebForm(Implementation())

1 1

css File with Nevow
by dsalvatore＠freesurf.fr 18 Nov '05

18 Nov '05

Hello, I would like to use an externel xml file linked to a style sheet <html xmlns:nevow="http://nevow.com/ns/nevow/0.1"> <head> <link rel="stylesheet" href="style.css" type="text/css" /> </head> ....... The problem is that the syle sheet is not teken in account. Could someone tell me how to proceed ? Thank you very much Regards Salvatoe

2 2

bug in README
by Jeff Bauer 15 Nov '05

15 Nov '05

In current README: < svn co svn://divmod.org/svn/Nevow/trunk Nevow > svn co http://divmod.org/svn/Divmod/trunk/Nevow Nevow Is there a better way to report bugs? The divmod trac is restricted. -- Jeff Bauer http://serpentaddiction.blogspot.com Rubicon, Inc. http://www.rubic.com

3 2

Use Nevow in conjunction with XMLRPC
by Remi Cool 15 Nov '05

15 Nov '05

G'day, My goal is to create a Twisted server that implements XMLRPC, Nevow and PHP (for transition of the old webapp). XMLRPC works again (thanks to Daniel and Matt) ... but I can't get Nevow working as a child of the httpResource. Or is there a better (Twisted) way of doing this (without using tap)? The code: from formless.annotate import TypedInterface, Integer, String from nevow import rend, tags, loaders from formless import webform class ISimpleMethod(TypedInterface): def simple(self, name=String(description="Your name."), age=Integer(description="Your age.")): """Simple Please enter your name and age. """ class Implementation(object): implements(ISimpleMethod) def simple(self, name, age): print "Hello, %s, who is %s" % (name, age) class WebForm(rend.Page): document = loaders.stan(tags.html[ tags.body[ tags.h1["Here is the form:"], webform.renderForms('original')]]) class httpResource(resource.Resource): implements(resource.IResource) def __init__(self, service): resource.Resource.__init__(self) self.service = service self.putChild('RPC2', Example(self.service)) self.putChild('formtest', resource.Resource(WebForm(Implementation()))) def render(self, request): self._clientIP = request.getClientIP() return resource.Resource.render(self, request) def render_GET(self, request): """Process HTTP GET Requests.""" print 'GET: request ->', request return '<html><body><h3>Not Implemented</h3></body></html>' def getChild(self, path, request): """This method handles http calls""" print 'getChild path:', path print 'getChild request:', request if path=="": return httpResource(self.service) else: return httpResource(self.service) components.registerAdapter(httpResource, IowwService, resource.IResource)

1 1

Can't get XMLRPC server working with Twisted 2.1
by Remi Cool 15 Nov '05

15 Nov '05

Hello Twisters, I've looked in the documentation, searched the archives and the web, but found no solution to the XMLRPC problem I'm having. I've used the finger example code to create an XMLRPC server, but I keep getting the 405 Method not allowed error. I'm probably overlooking something very obvious, call me stupid, but I can't get it to work. Below the code I'm using. If someone has a clue ... please enlighten me. -- Remi -- Server code: #!/usr/bin/env python # -*- coding: iso-8859-15 -*- """""" import sys from twisted.application import internet, service from twisted.internet import reactor, protocol, defer from twisted.web import resource, server, static, xmlrpc from twisted.python import components, rebuild from zope.interface import Interface, implements class myXMLRPC(xmlrpc.XMLRPC): """This class contains all root xmlrpc methods and the modules subhandler.""" def __init__(self, service): xmlrpc.XMLRPC.__init__(self) self.service = service def xmlrpc_echo(self, x): """Simple echo function""" return x def catchError(err): return "Internal error in server" class IowwService(components.Interface): """""" def rebuild(self, modname): """Rebuild classes in given module""" class httpResource(resource.Resource): implements(resource.IResource) def __init__(self, service): resource.Resource.__init__(self) self.service = service self.putChild('RPC2', myXMLRPC(self.service)) def render(self, request): self._clientIP = request.getClientIP() return resource.Resource.render(self, request) def render_GET(self, request): """Process HTTP GET Requests.""" return '<html><body><h3>Not Implemented</h3></body></html>' def getChild(self, path, request): """This method handles http calls""" return httpResource(self.service) components.registerAdapter(httpResource, IowwService, resource.IResource) class owwService(service.Service): """""" implements(IowwService) def rebuild(self, modname): """Rebuild classes in given module""" mod = sys.modules[modname] rebuild.rebuild(mod) def main(): """""" application = service.Application('OWW', uid=100, gid=100) s = owwService() serviceCollection = service.IServiceCollection(application) internet.TCPServer(7080, server.Site(resource.IResource(s))).setServiceParent(serviceCollection) serviceCollection.startService() reactor.run() if __name__ == '__main__': main() And the client code: #!/usr/bin/env python from twisted.web.xmlrpc import Proxy from twisted.internet import reactor def printValue(value): print repr(value) reactor.stop() def printError(error): print 'error', error reactor.stop() proxy = Proxy('http://localhost:7080') proxy.callRemote('echo', 'hello world').addCallbacks(printValue, printError) reactor.run()

3 3

PHP support on Windows
by Abdallah Deeb 14 Nov '05

14 Nov '05

Hello everyone, I'm trying to run some php code on twisted.web using some simple code. it works on my gentoo system but fails on Windows XP. The problem only appears when running PHP code, html is served with no problems. The code is as follows: (taken from one of the samples) import os from twisted.internet import reactor from twisted.application import internet, service from twisted.web import static, server, twcgi, script class PHPScript(twcgi.FilteredScript): filter = 'c:\\PHP\\php' root = static.File(os.getcwd()) root.processors = { '.php': PHPScript, '.epy': script.PythonScript, '.rpy': script.ResourceScript, } application = service.Application('web') site = server.Site(root) reactor.listenTCP(1999, site) reactor.run() and the error I get is ... (partially) C:\Python24\lib\site-packages\twisted\internet\default.py, line 179 in spawnProcess 177 # raise NotImplementedError, "process not available since win32all is not installed" 178 else: 179 raise NotImplementedError, "process only available in this " \ 180 "reactor on POSIX, use win32eventreactor on Windows" I'm running php 4.3.7 with the latest release of twisted, python 2.4.1 and Windows XP Pro TIA Abdallah Deeb

6 7

Weird problem with XMLRPC -> ('405', 'Method Not Allowed')
by Remi Cool 10 Nov '05

10 Nov '05

I've run into a problem with my twisted xmlrpc test server (using twisted version 2.01 or 2.1). Every time the client calls the echo function a '405 Method Not Allowed is returned'. This code ran in Twisted 1.3 without problems ... what's changed besides the zope interface implements. Any ideas? Here's the server code: #!/usr/bin/env python # -*- coding: iso-8859-15 -*- """""" import sys from twisted.application import internet, service from twisted.internet import reactor, protocol, defer from twisted.web import resource, server, static, xmlrpc from twisted.python import components, rebuild from zope.interface import Interface, implements class myXMLRPC(xmlrpc.XMLRPC): """This class contains all root xmlrpc methods and the modules subhandler.""" def __init__(self, service): xmlrpc.XMLRPC.__init__(self) self.service = service def xmlrpc_echo(self, x): """Simple echo function""" return x def catchError(err): return "Internal error in server" class IowwService(components.Interface): """""" def rebuild(self, modname): """Rebuild classes in given module""" class httpResource(resource.Resource): implements(resource.IResource) def __init__(self, service): resource.Resource.__init__(self) self.service = service self.putChild('RPC2', myXMLRPC(self.service)) def render(self, request): self._clientIP = request.getClientIP() return resource.Resource.render(self, request) def render_GET(self, request): """Process HTTP GET Requests.""" return '<html><body><h3>Not Implemented</h3></body></html>' def getChild(self, path, request): """This method handles http calls""" return httpResource(self.service) components.registerAdapter(httpResource, IowwService, resource.IResource) class owwService(service.Service): """""" implements(IowwService) def rebuild(self, modname): """Rebuild classes in given module""" mod = sys.modules[modname] rebuild.rebuild(mod) def main(): """""" application = service.Application('OWW', uid=100, gid=100) s = owwService() serviceCollection = service.IServiceCollection(application) internet.TCPServer(7080, server.Site(resource.IResource(s))).setServiceParent(serviceCollection) serviceCollection.startService() reactor.run() if __name__ == '__main__': main() And the client code: #!/usr/bin/env python from twisted.web.xmlrpc import Proxy from twisted.internet import reactor def printValue(value): print repr(value) reactor.stop() def printError(error): print 'error', error reactor.stop() proxy = Proxy('http://localhost:7080') proxy.callRemote('echo', 'hello world').addCallbacks(printValue, printError) reactor.run()

1 1

why doesn't work nevow.example.callremote with IE (InternetExplorer)?
by Peter Arwanitis 10 Nov '05

10 Nov '05

Hi there, callremote example demonstrates the notifyOnDisconnect() feature for athena-livepages (using twisted2.0.1 / nevow0.6.0 / python2.3.5 on winXP). Firefox triggers with a reload of the page or a change to another page the callbacks added to notifyOnDisconnect _immediately_ --> perfect! 'A client lives!' 'A client dies!' twisted.internet.error.ConnectionDone: Connection was closed cleanly. 'A client lives!' 'A client dies!' twisted.internet.error.ConnectionDone: Connection was closed cleanly. ... Why doesn't this work with IE, too??? The connections dies in a delayed timeout... but not immediately. The problem is, that meanwhile open connections from IE to webserver was established, and they are limited to TWO!!! And the whole things hangs, waiting for timeouts to free the connections.So this will be a serious bottleneck! (at least for my design :-/) 'A client lives!' 'A client lives!' ... ... later: 'A client dies!' twisted.internet.error.TimeoutError: User timeout transports created by client. thanks to exarkun on irc and his hint to http://www.winguides.com/registry/display.php/536, you can play with number of needed connections, but leaving / refreshing a livepage The mechanism is based on twisted.web.server.Request.notifyFinish() and hopes that this one is throwing a "twisted.internet.error.ConnectionDone: Connection was closed cleanly." if the connection got lost. But this error to trigger the req.notifyFinish().addErrback(...) does not come with IE leaving or reloading a page. Is this specific for me, or can somebody else reproduce this "feature". Does someone have deeper knowledge about the live-connection hold with IE from athena? And how notifyOnDisconnect() could work with IE, too??? thanks a lot greetings from germany, munich Peter (=PA=)

1 2

Instance of child element class never goes away?
by Jay 09 Nov '05

09 Nov '05

Hi, all. This is my first swing at using twisted...and I'm not much of a python jockey either. I'm using twisted.web2, python 2.4.2 on FreeBSD. I've got a simple (two page) application right now -- most of it is shamelessly cribbed from the example provided in the documentation. There's the TopLevel which has one child page -- child_antitrypsin. child_antitrypsin is an instance of a Query class that returns a plain old HTML string via http.Response. Now, to get that string, the Query class has to send a request to another server, get and parse an XML document and construct the string. All well and good. The problem I'm having is that the first child_antitrypsin that gets instantiated seems to be the only one that ever gets created. Refreshing the page -- or clicking on the link -- gives me the string twice...or three times or however many. So, if the first result was "APPLE", the second time, I'd get "APPLEAPPLE" and so on. lynx -dump -head shows that the Last-Modified time is always the same (ie, the creation time). The behavior I expected was for the link to get clicked, the child to get instantiated, do its work, return a result and go away. Do I need to explicitly kill the child object? Thanks! -- Jay.

2 2

Problems with web2.test.test_static.TestFileSaver
by Wilfredo Sánchez Vega 08 Nov '05

08 Nov '05

web2.test.test_static.TestFileSaver has been failing on my DAV branch. dreid and I were looking into it at SHDH and were generally baffled by the breakage. I remain baffled, but have managed to figure out that the test isn't breaking due to the addition of code, but by the simple existence of the test modules in my code. I can reproduce the problem in trunk by doing the following: cd twisted/web2 mkdir dav touch dav/__init__.py mkdir test touch dav/test/__init__.py echo "import twisted.web2.static" > dav/test/test_OPTIONS.py And then run "trial twisted.web2" and watch it blow up in TestFileSaver. In twisted.web2.test.test_static.TestFileSaver.testCompareFileContents (), when the callback gotFname() gets called, if the dav test is not present, then fname is being set to this string: fname = "y>\ntwisted.web2.test.test_static/TestFileSaver/ testCompareFileContents/2336.1/4eb6d0fcd8319ae61aa0639f3c4c1128: File type not allowed MimeType('text', 'plain', {})" ... which is apparently including some previous error condition which is being passed along in a strange sort of way. -wsv

2 1

HTTP client TODOs
by Jan Alonzo 07 Nov '05

07 Nov '05

Hi, Good day everyone! I have a project that I want to port to Twisted. It's an HTTP client (feed aggregator) and one of the reasons why I want to port it is so that I can take advantage of what twisted has to offer and focus on other more important features (and having test apps is, I guess, also good for the project right? :) I am new to twisted and one of my priority right now is to help out with the HTTP client code in the web2 module. Is there a TODO specific to the client library somewhere that I can look at? Cheers, -- Jan Alonzo <jmalonzo(a)unpluggable.com>

5 7

Re: Memory leak with twisted web server on QNX
by Nagy Zsombor 07 Nov '05

07 Nov '05

Hello everyone! [this is my first post] I had a serious memory leak with twisted 2.0.1 and twisted web 0.5, when I created a web server with TLS, and every client connection increased the memory usage. I played with it a lot, and found out, if I comment out line of code in twisted.internet.posixbase, the leak is gone... This one: 322 def _startTLS(self): 323 self.TLS = 1 324 klass = self.__class__ 325 class TLSConnection(_TLSMixin, klass): 326 implements(interfaces.ISSLTransport) !! 327 #components.backwardsCompatImplements(TLSConnection) 328 self.__class__ = TLSConnection So if I uncomment this 'backwardCompatImplements' there is a serious memory leak, if I comment it out, there is no leak. I can show you the test programs if you want me to. Bye, Zsombor

4 4

problems with select boxes.
by Alberto Trujillo 07 Nov '05

07 Nov '05

Hi everybody: My question is the next one. I have implement a form in stan with two select box. The first one is full of datas (select1), and the second one is empty(select2). Also I have two buttons, one to transfer datas from select1 to select2 (button1) and the other to do the opposite. Until now I only can get the value of the item which is selected, but I don't know how to get the text. This is what I'm doing. /T.input(name="button1", value="+", type="button", onclick=livepage.server.handle("addItem", / /livepage.get("select1").value, livepage.get("select1").text)/ /..../ /def handle_addItem(self,ctx, value, text):/ / print "value: %s text: %s" % (value, text)/ / yield livepage.set("select2", value, text)/ I only can see the value with the print function, because text is undefined. How can I get the text, and how can add this values after in the select2? I'm running Nevow 0.5. Thanks in advance.

1 0

Re: Memory leak with twisted web server on QNX
by Nagy Zsombor 05 Nov '05

05 Nov '05

> This should be fixed in r15022. Could you give it a try and let me know? If it fixes it, we should be able to get this into the next point release. Yes, it fixes it, there is no leak now! :) Thanks! Zsombor Nagy (in my previous mail, i wrote it wrong. it was in twisted.internet.tcp, not in posixbase, of course)

1 0

Memory leak with twisted web server on QNX
by denis.leborgne＠rieter.com 04 Nov '05

04 Nov '05

Hi, I use twisted as a very simple web server to serve python scripts. I now have a problem of memory leak on the server. I use Python 2.2.1 on QNX 6.3, Twisted version is 1.3.0. I made the following test scripts : Web server from twisted.web import server, resource,static,script from twisted.internet import reactor root = static.File("site") root.processors = {'.py': script.PythonScript, '.rpy': script.ResourceScript} site = server.Site(root) reactor.listenTCP(8500, site) reactor.run() Test script (.rpy file) from twisted.web import resource class Test(resource.Resource): isLeaf = True def render_GET(self, request): return """<html> <head> <meta http-equiv="refresh" content="5"> </head> Hello, world!</html>""" resource = Test() About every 4 "refresh", the memory used by my server increases by 96k, with nor release of memory. I checked the object number by watching len(gc.get_objects()), but it is stable. Any idea to help me to solve this problem, my server is expected to run continuously. Thanks. Denis

2 2

transferring datas between select box.
by Alberto Trujillo 03 Nov '05

03 Nov '05

Hi everybody: My question is the next one. I have a form with two select box. The first one is full of datas (select1), and the second one is empty(select2). Also I have two buttons, one to transfer datas from select1 to select2 (button1) and the other to do the opposite. I have done this before with javascript, but now I need to do it in Nevow 0.5 and with livepage. Could anybody help me? Thanks in advance.

1 0

livepage connection "timing out"/dying randomly
by Robby Dermody 02 Nov '05

02 Nov '05

Hey guys, I seem to have a problem with client browsers to my guarded livepage application loosing their livepage connections. It seems that the guard session doesn’t expire, but the livepage system on the server side seems like it will loose track of the client’s nevow handle. This is under the Nevow 0.5.0 release, and it happens under both IE 6.0.x and Firefox 1.0.x. Basically, my server app makes livepage calls to the client browser js via clientHandle.call() to reflect dynamically updated data as it happens… (maybe one call every 4 seconds). At this point I found this problem (that at some point these updates in the client would stop, while the server was still making the livepage call() invocations like everything was fine and dandy). The problem was that things just seemed to die, and I could find no error output showing why. Well, in my search for a fix/error output, I added a js function on the client that calls server.handle('refreshSession()') every 120 seconds via the use of repeated setTimeout() calls. The corresponding handle_refreshSession() function on the server gets that client's session object and touch()es it. This will start out working fine for usually a few hours (the session timeout is 1200 seconds currently), and the client will stay logged in. Then after some seemingly arbitrary amount of time, I will start getting the following errors, one set for each refreshSession() call: From the client side (firefox java console): Error: syntax error Source File: http://216.148.216.20:8800/mon/nevow_glue.js Line: 155 Source Code: <html><head><title>Exception</title></head><body><style type="text/css"> From a glance at nevow_glue.js, it looks like the server returned an exception page to the client and nevow_clientToServerEvent() in nevow_glue.js didn’t like that when it tried to evaluate it as javascript code, or some kind of javascript result. On the server side I get the following python exception: ---**** EXCEPTION START ****--- Traceback (most recent call last): File "/usr/lib/python2.4/site-packages/twisted/internet/defer.py", line 216, in addCallback callbackKeywords=kw) File "/usr/lib/python2.4/site-packages/twisted/internet/defer.py", line 207, in addCallbacks self._runCallbacks() File "/usr/lib/python2.4/site-packages/twisted/internet/defer.py", line 328, in _runCallbacks self.result = callback(self.result, *args, **kw) File "/usr/lib/python2.4/site-packages/nevow/appserver.py", line 308, in handleSegment return defer.maybeDeferred( --- <exception caught here> --- File "/usr/lib/python2.4/site-packages/twisted/internet/defer.py", line 117, in maybeDeferred result = f(*args, **kw) File "/usr/lib/python2.4/site-packages/nevow/livepage.py", line 596, in locateChild client = self.clientFactory.clientHandles[handleId] exceptions.KeyError: '2' ---**** EXCEPTION END ****--- In this case, the key ‘2’ was the setting of the client’s “nevow_clientHandleID” variable. This will happen every time the client tries to make the call (e.g. every 120 seconds). I think these two types of updates I’m doing (one where the server tries to call a js method on the client when its data is updated, and one where the client periodically “pings” the server) are both exposing the same error. The only difference is that the one where the client pings the server with the server.handle() call exposes some error messages of what may be going wrong. Might I be forgetting to do something, or using livepage improperly? My goal is to make it so that, as long as a client’s browser is logged in and at my page, they will keep getting livepage events indefinitely. Might the newest version from the repository fix this? Thanks for any help, Robby

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