Mailman 3 April 2005 - Twisted-web

Multiple submit buttons with formless
by Dave Cook 11 Apr '05

11 Apr '05

First my question: is there an alternate way to do multiple submit buttons with formless than adding annotate.Button()'s? Maybe the annotate.List or Group stuff, whatever those do? I'm hoping someone will say, "You idiot, you don't just do it by sticking more Button()s in." I ask, because ButtonRenderer is broken, and has been broken for a while, and I can't imagine that people have only needed one button. It's broken because there are no 'name' attributes in the <input> tag, and thus no way to distinguish the buttons. There are several ways to fix this: patch the code (submitted to issues by me and others), "patch" the ButtonRenderer class like ButtonRenderer.rend = lambda c, d: input(type='submit', value=d.label, name=d.name, id=keyToXMLID(c.key)) or create your own renderer (code attached). Yet another way is to do your own layout and get the button info from request.args (example stan attached). Hope this will be helpful to somebody, I'm still groping my way through this. Dave Cook

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exception when try to list example source code?
by John Mudd 10 Apr '05

10 Apr '05

I get a list of exceptions when I try to look at the source code from the Examples page. It's basically the same no matter which source file I try to view. I'm using 4,1 Nevow & Twisted but got the same with 3.0 Nevow. Any suggestions? Starts with this: exceptions.AttributeError: 'module' object has no attribute 'kwdict' 127 128 try: 129 result = f(*args, **kw) 130 except: Locals args (PageContext(tag=<Sources object at 0x4067ccac>, remembrances={'nevow.inevow.ICurrentSegments': ('sources', 'most_basic.py'), 'nevow.inevow.IData': <Sources object at 0x4067ccac>, 'nevow.inevow.IRenderer': <Sources object at 0x4067ccac>, 'nevow.inevow.IRendererFactory': <Sources object at 0x4067ccac>, 'nevow.inevow.IRemainingSegments': (), 'nevow.inevow.IMacroFactory': <Sources object at 0x4067ccac>, 'nevow.inevow.IResource': <Sources object at 0x4067ccac>}),) kw {} f <bound method Sources.renderHTTP of <Sources object at 0x4067ccac>> Ends with this: /home/mudd/pkgs/python/lib/python2.4/site-packages/twisted/python/htmlizer.py, line 37 in printtoken 35 self.parameters = 1 36 elif type == tokenize.NAME: 37 if keyword.kwdict.has_key(token): 38 type = 'keyword' Locals self <twisted.python.htmlizer.TokenPrinter instance at 0x40f7038c> token 'from' type 1 Globals keyword <module 'keyword' from '/home/mudd/pkgs/python/lib/python2.4/keyword.pyc'> tokenize <module 'tokenize' from '/home/mudd/pkgs/python/lib/python2.4/tokenize.pyc'>

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__start_session__ and wget
by Andrea Arcangeli 09 Apr '05

09 Apr '05

I got annoyed by wget https://www.cpushare.com/downloads/cpushare-0.16.tar.bz2 creating a weird file called cpushare-0.16.tar.bz2__start_session__=1, so I removed it ;). I wonder if this risks to break anything w.r.t. browser caching? Everything is working fine so far on my site. Since my session is always ssl protected, I doubt caching could ever be an issue for my usage, but even the nevow examples in cleartext seems ok. Comments welcome, and keep up the great work! (btw, I won't read emails until Monday) Index: Nevow/nevow/guard.py =================================================================== --- Nevow/nevow/guard.py (revision 1413) +++ Nevow/nevow/guard.py (working copy) @@ -259,7 +259,8 @@ if path.startswith(SESSION_KEY): key = path[len(SESSION_KEY):] if key not in self.sessions: - return urlToChild(request, *segments[1:], **{'__start_session__':1}), () + #return urlToChild(request, *segments[1:], **{'__start_session__':1}), () + return urlToChild(request, *segments[1:]), () self.sessions[key].setLifetime(self.sessionLifetime) if cookie == key: # /sessionized-url/${SESSION_KEY}aef9c34aecc3d9148/foo @@ -267,7 +268,8 @@ # we are this getChild # with a matching cookie self.sessions[key].sessionJustStarted = True - return urlToChild(request, *segments[1:], **{'__session_just_started__':1}), () + #return urlToChild(request, *segments[1:], **{'__session_just_started__':1}), () + return urlToChild(request, *segments[1:]), () else: # We attempted to negotiate the session but failed (the user # probably has cookies disabled): now we're going to return the

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Using synchronous (blocking) code with Nevow
by Xif 06 Apr '05

06 Apr '05

Hello everyone I have a library of Python scripts that I need to use with my upcoming web-application. Unfortunately, those scripts block; for example, some of the objects I need to construct take several seconds each to return an instance from __init__(). How can I still use that code inside Nevow? (Using a different web server instead of Twisted's is definitely an option, if it doesn't entail any significant disadvantages.) Xif

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nevow.compy.MetaInterface not compatible to new Zope Interface style
by Nik Klever 06 Apr '05

06 Apr '05

Before switching to Twisted 2.0.0 and Nevow 0.4.1 I used a class inherited from rend.Page in a resource script (a short example of this method was renaming hellostan.py to hellostan.rpy and replacing the last 3 lines to "resource = Page()" ) This method brings now the error message "twisted.python.components.CannotAdapt: <Page object at 0x...> to <MetaInterface twisted.web.resource.IResource>". Looking into the code I found that nevow.compy.MetaInterfaces is not compatible with the new Twisted 2.0.0 twisted.python.components.MetaInterface, because it's borrowed from an older version of Twisted 1.3.0 twisted.python.components.MetaInterface. Is there a plan to update nevow.compy to the new Zope Interface style ? Thanks in advance Nik

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Binding twistd to a Specific IPv4 Address
by Eric Radman 04 Apr '05

04 Apr '05

Is there a way to instruct twistd to bind to a specific IPv4 address? Right now I'm setting up each server on it's own port and redirecting packets with iptables: # Apache iptables -t nat -A PREROUTING -p tcp -d 10.1.1.1 --dport 80 \ -j DNAT --to-destination 10.1.1.1:8001 # Twisted 1 iptables -t nat -A PREROUTING -p tcp -d 10.1.1.2 --dport 80 \ -j DNAT --to-destination 10.1.1.2:8002 # Twisted 2 iptables -t nat -A PREROUTING -p tcp -d 10.1.1.3 --dport 80 \ -j DNAT --to-destination 10.1.1.3:8003 This is kind of messy. -- Eric Radman

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Safari and LivePage in nevow 0.4
by Dave Cook 04 Apr '05

04 Apr '05

LivePage in 0.4.1 seems to have stopped working with Safari. Even the liveevil.py example no longer works. Has anyone else seem this problem? Dave Cook

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nevow Page caching
by Andrea Arcangeli 03 Apr '05

03 Apr '05

Just as reminder, this is a pending patch against SVN trunk to add an easy page-wide caching with timeout or persistent. Index: Nevow/nevow/rend.py =================================================================== --- Nevow/nevow/rend.py (revision 1399) +++ Nevow/nevow/rend.py (working copy) @@ -30,6 +30,7 @@ from nevow import flat from nevow.util import log from nevow import util +from nevow import url import formless from formless import iformless @@ -405,6 +406,8 @@ self.children[name] = child +_CACHE = {} + class Page(Fragment, ConfigurableFactory, ChildLookupMixin): """A page is the main Nevow resource and renders a document loaded via the document factory (docFactory). @@ -418,8 +421,37 @@ afterRender = None addSlash = None + cache = False + lifetime = -1 + __lastCacheRendering = 0 + flattenFactory = lambda self, *args: flat.flattenFactory(*args) + def hasCache(self, ctx): + if not self.cache: + return + + _now = now() # run gettimeofday only once + timeout = _now > self.__lastCacheRendering + self.lifetime and \ + self.lifetime >= 0 + c = self.lookupCache(ctx) + if timeout or c is None: + # stop other renders + self.__lastCacheRendering = _now + c = None + return c + def cacheRendered(self, ctx, c): + if not self.cache: + return + # overwrite the deferred with the data + self.storeCache(ctx, c) + def cacheIDX(self, ctx): + return str(url.URL.fromContext(ctx)) + def storeCache(self, ctx, c): + _CACHE[self.cacheIDX(ctx)] = c + def lookupCache(self, ctx): + return _CACHE.get(self.cacheIDX(ctx)) + def renderHTTP(self, ctx): if self.beforeRender is not None: return util.maybeDeferred(self.beforeRender,ctx).addCallback( @@ -444,11 +476,18 @@ if self.afterRender is not None: return util.maybeDeferred(self.afterRender,ctx) - if self.buffered: + c = self.hasCache(ctx) + if c is not None: + finishRequest() + return c + + if self.buffered or self.cache: io = StringIO() writer = io.write def finisher(result): - request.write(io.getvalue()) + c = io.getvalue() + self.cacheRendered(ctx, c) + request.write(c) return util.maybeDeferred(finishRequest).addCallback(lambda r: result) else: writer = request.write @@ -532,7 +571,6 @@ else: ## Use the redirectAfterPost url ref = str(redirectAfterPost) - from nevow import url refpath = url.URL.fromString(ref) magicCookie = '%s%s%s' % (now(),request.getClientIP(),random.random()) refpath = refpath.replace('_nevow_carryover_', magicCookie)

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nevow development refresh
by Jeffrey Kunce 03 Apr '05

03 Apr '05

Hi- This is most probably FAQ, but I swear I couldn't find it - please have mercy on a nevow/twisted newbie :) If I make some changes in the python code for a nevow application, is there a way to refresh and test those changes without killing/restarting my twisted server? Thanks. --Jeff

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newbie question : first template
by Sylvain de Tilly 01 Apr '05

01 Apr '05

Hello, I'm just trying Nevow and I follow the BIG example page. But I'm blocked in the juste first test : print a string with the template. Here my code : ------------------------------ <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en" xmlns:nevow="http://nevow.com/ns/nevow/0.1"> <head> <title>title</title> </head> <body> <h3>very simple test</h3> Hello nevow... Could you see my <span nevow:data="test" /> ? </body> </html> ------------------------------------ # -*- python -*- # -*- coding: utf-8 -*- from twisted.application import service, internet from nevow import appserver, rend, loaders class Page(rend.Page): addSlash=True docFactory = loaders.xmlfile('./htmlpage_first.html') def data_test( self, context, data ) : return "pattern" application = service.Application( 'appli' ) website = appserver.NevowSite( resource=Page() ) webserver = internet.TCPServer( 8080, website ) webserver.setServiceParent( application ) ----------------------------------------------------- It must be something stupid but I could'nt find it ! Thanks in advance, -- Sylvain de Tilly

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