Mailman 3 February 2005 - Twisted-web

canvas without flash and optimization patches
by Stefano Debenedetti 21 Feb '05

21 Feb '05

Hello, I did some further tests on Canvas, the compilation errors I got with KineticFusion were definitely trivial (only two missing semicolons) so I prepared a little patch that corrects those and adds the RVML file, which includes a comment with instructions for downloading KineticFusion and building the Canvas SWF with it. I also turned compression on for a further size improvement, now the generated SWF is less than 2KB. Perhaps more importantly, I found out why the Canvas demo is crashing Mozilla/Firefox on linux: it is too fast (i.e. the linux Flash player is too crappy)! Indeed it is not crashing, if you stop the server the browser resurrects, so I guess it is more appropriate to call it a choke. The demo uses twisted.internet.task to send commands to the client approximatively every 0.25 seconds, raising that value to 0.3 is enough to avoid the choke, at least on my system. So I tried optimizing the canvas.as file and I found out that by changing the Canvas protocol in order to use plain old crappy TSV instead of XML gives it a performance boost that allows me to push the above mentioned refresh rate of the demo to 0.21, i.e. even better than the 0.25 that was unreachable before. Of course this has other drawbacks, for example you have take care of potential conflicts between the separator token you choose and the string data you want to send to the client, you lose ease of extensibility of the hierarchical structure and so on but it's worth giving it a try when the goal is absolute performance. The first patch I attach is just the semicolons fixes + the RVML file, the second one is the same plus the optimizations, sorry about the data duplication but I couldn't figure out a quick way to do incremental patches with SVN without committing first. ciao ste

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No output on attr error
by Charles Moad 21 Feb '05

21 Feb '05

For this simple example I can call the soap method test and the reactor prints no error message. It correctly returns a fault of "Method test failed." since I did not import the string module. I post this code for a simple case, but I was running into this for fairly complex code. Shouldn't the reactor print some sort of error? I am using twisted-1.3.0. -------------------------------------------------- from twisted.web import server, soap from twisted.internet import reactor, defer class MySOAP(soap.SOAPPublisher): def soap_test(self): return string.split('hello world') reactor.listenTCP(10081, server.Site(MySOAP())) reactor.run() -------------------------------------------------- Thanks, Charlie

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more MeLearnNevow wiki
by Jeff Bauer 20 Feb '05

20 Feb '05

I've added a couple more entries to MeLearnNevow. http://divmod.org/users/wiki.twistd/nevow/moin.cgi/MeLearnNevow Please feel free to correct any mistakes in my commentary. I'm very much a slow beginner. Thanks. Jeff Bauer Rubicon, Inc.

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Atop Storeup
by Luis N 18 Feb '05

18 Feb '05

Would someone be able to explain how I can get something out of an Atop database such as http://www.divmod.org/cvs/trunk/doc/examples/atop-storeup.py?rev=5251&view=… a la http://radix.twistedmatrix.com/archives/000091.html using StoreUps.

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caching branch
by Andrea Arcangeli 18 Feb '05

18 Feb '05

The tags.cached keeps working fine in the caching branch (which btw applied cleanly on top of trunk). What doesn't work is the rend.Page. I'm very curious to compare the performance of the caching branch with my previous code that is currently online already. Locals rest [<listiterator object at 0x56c6fcac>] item <generator object at 0x56c6fc8c> gen <generator object at 0x56c6fc8c> /home/andrea/bin/x86_64/python/lib/python2.4/site-packages/nevow/flat/flatstan.py, line 234 in CachedSerializer 232 233 def CachedSerializer(original, context): 234 cache = ICache(original.scope(context)) 235 cached = cache.get(original.key, original.lifetime) Locals original <cached instance at 1455889540> context <WovenContext instance at 1455880172> Globals ICache <MetaInterface nevow.inevow.ICache> CachedSerializer <function CachedSerializer at 0x56c63614> I also suggest to apply this patch to the code or it doesn't even startup. --- Nevow/nevow/rend.py.~1~ 2005-02-18 04:39:54.208615490 +0100 +++ Nevow/nevow/rend.py 2005-02-18 05:06:15.272641191 +0100 @@ -30,6 +30,7 @@ from nevow import tags from nevow import flat from nevow.util import log from nevow import util +from nevow import url import formless from formless import iformless @@ -416,7 +417,7 @@ class Page(Fragment, ConfigurableFactory if self.buffered: io = StringIO() writer = io.write - def finisher(result): + def finisher(result): request.write(io.getvalue()) finishRequest() return result @@ -428,7 +429,7 @@ class Page(Fragment, ConfigurableFactory doc = self.docFactory.load() if self.cache: - name = url.URL.fromContext(ctx).path + name = str(url.URL.fromContext(ctx)) doc = tags.cached(name, self.lifetime)[doc] ctx = WovenContext(ctx, tags.invisible[doc]) @@ -504,7 +505,6 @@ class Page(Fragment, ConfigurableFactory else: ## Use the redirectAfterPost url ref = str(redirectAfterPost) - from nevow import url refpath = url.URL.fromString(ref) magicCookie = str(now()) refpath = refpath.replace('_nevow_carryover_', magicCookie)

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Parametrized data_foo method?
by Sridhar Ratna aka Srid 16 Feb '05

16 Feb '05

<n:invisible data="foo" .... I would like to pass custom argument to data_foo depending the usage in xml templates. Is this possible? Another question ... <div n:data="foo"> <h2> <n:invisible n:data="title" n:render="post_title"/> </h2> data_foo returns a dictionary say {"title":... "name": ... } Here how to access the "name" dict item from render_post_title? -- Sridhar Ratna - http://srid.bsdnerds.org

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various formless types
by andrea＠cpushare.com 15 Feb '05

15 Feb '05

These are some formless types I'm using in my app. I think it's a good idea to share it with you, since they can be useful not just to me. The reason of the webform.freeformDefaultContentPattern change is to use div instead of stan, I'm doing some strange stuff, so without div it becomes not compliant html. I need the context as last parameter of the processor handler, not in the below types, but in others. Note also the RequiredChoice, I believe the check "x not in self.choices" is required for security reasons, most people will expect the client does the right thing, but it's not forced to without such check. I only use requiredchoice and never choice. I also wonder if it really worth the new API that slows down it so much with the normal rendering, but let's say that's a more general problem with compy and getinterfaces. Plus the new API is way confusing, integers gets converted to strings and if you conver them back to integers with valueToKey the processor will forget the value, the processor remembers the value only if the coerce returns a string. That might actually be a bug. Anyway the below workaround in my requiredchoice works (i.e. always try to convert to int in the coerce for the security check, but keep returning a string). I only use lists of strings or integers as choices for requiredchoice of course, so I'm fine. class IntegerRange(annotate.Integer): def __init__(self, min = None, max = None, *args, **kw): super(IntegerRange, self).__init__(*args, **kw) self.min = min self.max = max self.requiredFailMessage = 'Please enter an integer between %d and %d.' \ % (self.min, self.max) def coerce(self, val, configurable): v = super(IntegerRange, self).coerce(val, configurable) if v > self.max or v < self.min: raise annotate.InputError("Integer must be between %d and %d." % (self.min, self.max)) return v class RealRange(annotate.Real): def __init__(self, min = None, max = None, *args, **kw): super(RealRange, self).__init__(*args, **kw) self.min = min self.max = max self.requiredFailMessage = 'Please enter a real number between %d and %d.' \ % (self.min, self.max) def coerce(self, val, configurable): v = super(RealRange, self).coerce(val, configurable) if v > self.max or v < self.min: raise annotate.InputError("Real must be between %d and %d." % (self.min, self.max)) return v class MaxlengthString(annotate.String): def __init__(self, *args, **kwargs): if 'maxlength' in kwargs: self.maxlength = kwargs['maxlength'] del kwargs['maxlength'] else: self.maxlength = 10 super(MaxlengthString, self).__init__(*args, **kwargs) def coerce(self, val, configurable): r = super(MaxlengthString, self).coerce(val, configurable) if search_for_invalid_chars.search(r): raise annotate.InputError("%r contains invalid characters." % val) if len(r) > self.maxlength: raise annotate.InputError("%r is too long, maximum is %d." % (val, self.maxlength)) return r def invalid_email(email): return not re.match(r'^[\w\-~@.+]+\Z', email) or \ re.search(r'@[^@]*@', email) or \ not re.match(r'^[\w\-~.+]+@.*[\w\-~+]+\.[\w]{2,}\Z', email) class Email(MaxlengthString): def coerce(self, val, configurable): r = super(Email, self).coerce(val, configurable) if invalid_email(val): raise annotate.InputError("%r is not a valid email address." % val) return r class MaxlengthStringRenderer(webform.StringRenderer): def input(self, context, slot, data, name, value): if data.typedValue.getAttribute('hidden'): T='hidden' else: T='text' return slot[ tags.input(id=formutils.keyToXMLID(context.key), type=T, name=name, value=value, maxlength=data.typedValue.maxlength, _class="freeform-input-%s" % T)] class ProcessTypedContext(compy.Adapter): __implements__ = iformless.IInputProcessor, def process(self, context, boundTo, data): """data is a list of strings at this point """ typed = self.original val = data[0] if typed.unicode: try: val = val.decode(getPOSTCharset(context), 'replace') except LookupError: val = val.decode('utf-8', 'replace') if typed.strip: val = val.strip() if val == '' or val is None: if typed.required: raise annotate.InputError(typed.requiredFailMessage) else: return typed.null return typed.coerce(val, boundTo, context) class MaxlengthPassword(MaxlengthString): requiredFailMessage = 'Please enter a password.' class MaxlengthPasswordRenderer(webform.PasswordRenderer): def input(self, context, slot, data, name, value): return [ tags.input(id=formutils.keyToXMLID(context.key), name=name, type="password", _class="freeform-input-password", maxlength=data.typedValue.maxlength), " Again ", tags.input(name="%s____2" % name, type="password", _class="freeform-input-password", maxlength=data.typedValue.maxlength), ] class Decimal(annotate.Typed): requiredFailMessage = 'Please enter a decimal number.' def coerce(self, val, configurable): # TODO: This shouldn't be required; check. # val should never be None, but always a string. if val is None: return None try: return decimal.Decimal(val) except decimal.InvalidOperation: raise annotate.InputError("%r is not a decimal number." % val) class ForcedBoolean(annotate.Boolean): pass class ForcedBooleanRenderer(webform.BooleanRenderer): def input(self, context, slot, data, name, value): ## The only difference here is the "checked" attribute; the value is still the same because ## we want true to be passed to the server when the checkbox is checked and the form ## is posted. node = tags.input(id=formutils.keyToXMLID(context.key), type="checkbox", name=name, value='True', _class="freeform-input-checkbox") if value: node(checked="checked") # HTML forms are so weak. If the checkbox is not checked, no value at all will be # in request.args with the name data.name. So let's force the value False to always # be in request.args[data.name]. If the checkbox is checked, the value True will # be first, and we will find that. return slot[node, tags.input(type="hidden", name=name, value="")] class RequiredChoice(annotate.Choice): requiredFailMessage = 'Please choose an option.' def coerce(self, val, configurable): r = super(RequiredChoice, self).coerce(val, configurable) if self.required and r == self.default: raise annotate.InputError(self.requiredFailMessage) try: x = int(val) except ValueError: x = val if x not in self.choices: raise annotate.InputError("Your web browser is malfunctioning") return r compy.registerAdapter(MaxlengthStringRenderer, MaxlengthString, iformless.ITypedRenderer) compy.registerAdapter(MaxlengthStringRenderer, Email, iformless.ITypedRenderer) compy.registerAdapter(MaxlengthPasswordRenderer, MaxlengthPassword, iformless.ITypedRenderer) compy.registerAdapter(ReadonlyTextRenderer, ReadonlyText, iformless.ITypedRenderer) compy.registerAdapter(webform.ChoiceRenderer, RequiredChoice, iformless.ITypedRenderer) compy.registerAdapter(ForcedBooleanRenderer, ForcedBoolean, iformless.ITypedRenderer) compy.registerAdapter(processors.ProcessPassword, MaxlengthPassword, iformless.IInputProcessor) webform.freeformDefaultContentPattern = tags.invisible[ tags.label(_class="freeform-label", _for=stan.slot('id'))[ stan.slot('label') ], tags.div(_class="freeform-input")[ stan.slot('input') ], tags.div(_class="freeform-error")[ stan.slot('error') ], tags.div(_class="freeform-description")[tags.label(_for=stan.slot('id'))[ stan.slot('description') ]]].freeze()

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file upload without formless
by Tazzo 15 Feb '05

15 Feb '05

I have some problem with formless and the use a did with locateChild method. I'm working to solve the problem using Configurable but it's hard because formbuilder.py is the only example I found ... is there any other example? In the meantime someone could send me a simple example of a file upload for big files (...no blocking code :) without formless? thanks -- Email.it, the professional e-mail, gratis per te: http://www.email.it/f Sponsor: Proteggi la tua moto dalle intemperie e... dagli sguardi indiscreti con il Telo Coprimoto! Clicca qui: http://adv.email.it/cgi-bin/foclick.cgi?mid=2744&d=20050214

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Connection reset by peer with
by snacktime 14 Feb '05

14 Feb '05

After a successful request, a minute later I get this exception. Why is the server still trying to read at this point? The resource class and code I use to start the server is below Traceback (most recent call last): File "/usr/local/lib/python2.4/site-packages/twisted/python/log.py", line 52, in callWithContext return context.call({ILogContext: newCtx}, func, *args, **kw) File "/usr/local/lib/python2.4/site-packages/twisted/python/context.py", line 64, in callWithContext return self.currentContext().callWithContext(ctx, func, *args, **kw) File "/usr/local/lib/python2.4/site-packages/twisted/python/context.py", line 43, in callWithContext return func(*args,**kw) File "/usr/local/lib/python2.4/site-packages/twisted/internet/default.py", line 535, in _doReadOrWrite why = getattr(selectable, method)() --- <exception caught here> --- File "/usr/local/lib/python2.4/site-packages/twisted/internet/tcp.py", line 98, in doRead return Connection.doRead(self) File "/usr/local/lib/python2.4/site-packages/twisted/internet/tcp.py", line 239, in doRead data = self.socket.recv(self.bufferSize) OpenSSL.SSL.SysCallError: (54, 'Connection reset by peer') ---------------------------------------------------------------------------------------------------- class SimpleWeb(resource.Resource): isLeaf = True def render_GET(self, request): return "<html>Hello world</html>" application = service.Application("otransact") OTService = service.IServiceCollection(application) web = SimpleWeb() site = server.Site(web) OTWeb = internet.SSLServer(8080, site,ServerContextFactory()) OTWeb.setServiceParent(OTService)

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Nevow with CGI - Using URLs in xml templates
by Sridhar Ratna aka Srid 14 Feb '05

14 Feb '05

I am using [1] Nevow in CGI environment Both relative and absolute URLs cannnot be used in xml templates. Consider the following apache setup. http://server/blog is rewritten (mod_rewrite) to http://server/cgi-bin/blog/index.py Now if an xml template contains this line <link rel="stylesheet" href="styles/screen.css" type="text/css" /> without rewrite the URL the browser will see is http://server/cgi-bin/blog/styles/screen.css and with rewritten the browser will see http://server/blog/styles/screen.css This depends on the current page, so sometimes the browser will see http://server/blog/2004/04/styles/screen.css (as the URL is relative). To cope with this problem with url.URL generation, I remember the parent-root URL in ctx. But I feel this is difficult to do with xml-templates as they are controlled by the user. Is there anyway to do translation in nevow? [1] http://srid.bsdnerds.org/blog/2005/02/06/nevow-with-cgi-and-wsgi-adaptor/ -- Sridhar Ratna - http://srid.bsdnerds.org

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