Mailman 3 October 2006 - Twisted-web

Question about url rewriting
by Gordon Scott 13 Oct '06

13 Oct '06

Hi I'm looking into using twisted and possibly twisted web in a small project I'm doing. I've been fumbling through the documentation trying to figure out how url rewriting works, or a way to short circuit request processing. Bascially I want to serve dynamic images but the clients are all expecting pretty urls that end in the correct file extension. An example might be http://someserver.com/images/600x800/watermark/file_a.png where 600x800 and watermark are file parameters since obviously I won't have '600x800', 'watermark', and 'file_a.png' as resources I either need to stop processing with the 'image' resource, or rewrite the request as /image/getImage.rpy?size=600x800&wm=watermark But I can't seem to find an example of terminating a request early or how to correctlly setup the a rewrite object. If anyone knows of where to go look at examples of such usage that would be great.

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fragments with child lookup
by Markus Schiltknecht 13 Oct '06

13 Oct '06

Hi, I would like to use the child lookup mechanism (locateChild or childFactory) but then again, I want Fragments. I'm sure there is a proper way to do what I want. Let my try to explain with a URL mapping to templates mapping: / -> common.xml /foo -> common.xml / foo.xml /bar -> common.xml / bar.xml /bar/baz -> common.xml / bar.xml / baz.xml common.xml as well as bar.xml both have a 'sub-content' renderer, which calls the next template. Of course this all happens dynamically. I've tried two things: a) make locateChild always return self, () and save which child it contains (and which it has to return as it's 'sub-content'. Unfortunately that stops the children lookup and I would have to invoke it locateChild of the child with segments[1:] myself. That seems ugly. b) make locateChild return the real Child. That seems the right thing to do. But then I only get the latest child's template (i.e. baz.xml when calling the URL '/bar/baz' in the example above). How do I make that latest child render it's parents first? Regards Markus

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athena widgets and IE
by Fabio Forno 12 Oct '06

12 Oct '06

Hi, I've a problem with an athena widget and IE. I define a widget for a LiveFragment like this one: var Widgets = {}; Widgets.ChatWidget = Nevow.Athena.Widget.subclass('Widgets.ChatWidget'); Widgets.ChatWidget.methods( function keyPressed (self, event) { if(event.key()["string"] == "KEY_ENTER") { text_area = window.document.getElementById("chat_area"); d = self.callRemote('got_text', text_area.value); d.addCallback(self.text_sent); } } ) Then in the xml template I try to get a reference to the just defined method in this way: widget = Nevow.Athena.Widget.get( document.getElementById("athena:1"); ); widget.keyPressed In firefox everything is ok, while in explorer 6.0 I get undefined. MOreover, in i.e. there is this oddity. if a loop on all the attributes of widgetwith for(var i in widget) , I get also the keyPressed method, but when I try to get it with widget[i], I keep having undefined as result. Any idea? -- Fabio Forno, PhD Istituto Superiore Mario Boella Jabber ID: xmpp:ff@kamin.polito.it ** Try Jabber http://www.jabber.org

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DOM manipulation in an athena widget
by Phil Mayers 09 Oct '06

09 Oct '06

Following on from my post of a couple of weeks ago, I'm rendering a *large* (~150 editable fields) form for a CRUD application and am wanting client-side processing of incremental updates to said form, since round-tripping adds considerable delay to the user experience. I'm sending the form as a table with appropriate athena:handler defined. On a mouse click, the athena:handler replaces the <span> containing the text with an <input type="text" /> or other control as appropriate. What I'm then trying to do is hook up an event handler to onBlur (or whatever) to compare the old and new values, set a dirty flag and enable the "save" button. I couldn't find a way to do this with the Divmod.NotQuiteMochiKit packages (indeed, they seem wedded to innerHTML), so I whacked MochiKit in the page header and tried this: class Frag(athena.LiveFragment): jsModule = u"db.Record" docFactory = loaders.stan( T.table(render=T.directive('sequence'), data=T.directive('sql'))[ T.tr(pattern='item', render=T.directive('mapping'))[ T.td[T.slot(name='fieldName')], T.td[ athena.handler(event='onclick', handler='editField'), T.span[T.slot(name='fieldValue')], ], # end of td ], # end of tr ]) ...and the jsmodule has: db.Record.methods( function editField(self, node, event) { if (node.inEdit) return false; /* make the textbox */ var tb = INPUT({'type': 'text', 'value': scrapeText(node)}); /* swap the span for a textbox */ replaceChildNodes( getElementsByTagAndClassName('span', null, node)[0], tb ); /* THIS FAILS */ connect(tb, 'onblur', self.saveField); return false; }); The nevow debug console thing logs "self has no properties" - what is self in this context of a widget method/event call? Why does it have no properties? Absent a more complete set of DOM and event handling functions, and given whatever the (to me) unfathomable incompatibility with Mochi and the Divmod runtime is, how does one attach event handlers to client-side created DOM nodes? Are the events normalised cross-browser as they are in Mochi? There's an "xbevent" function in one of the examples that indicates not? Suggestions welcome. Sorry for abruptness of mail, workrave is nagging me to stop typing...

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my guard implementation
by Manlio Perillo 08 Oct '06

08 Oct '06

Hi. I have updated http://divmod.org/trac/ticket/1435/ This ticket contains a reimplementation of guard, based on the work of dialtone. I have added several new features to dialtone original implementation. I would like to receive some feedback since I'm planning to use it in production. Thanks Manlio Perillo

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"Athena transport duplicate message, discarding"
by Fabio Forno 05 Oct '06

05 Oct '06

Hi, is it normal that I receive this message each time I call a method on the client (I'm using the example at this address)? -- Fabio Forno, PhD Istituto Superiore Mario Boella Jabber ID: xmpp:ff@kamin.polito.it ** Try Jabber http://www.jabber.org

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Looking for help on an equity or consulting basis
by Terry Jones 02 Oct '06

02 Oct '06

I'm finally reaching the stage where I want to build a web front end for the project my company is developing. I still have a strong preference for using Twisted, and I think it also makes sense to use Nevow/Athena. But... I'd prefer not to have to learn all the details of Nevow/Athena myself. I do the occasional svn up in the Nevow trunk, and see that there is what looks like daily activity there, but rather few of the changes are in the documentation. So it looks like a lot of functionality has been added to Nevow, and that it's not yet documented. Thus I have the strong feeling that the sensible route to getting the best out of Nevow is to ask for help from someone who's familiar with the current state of the art. So I'm firstly wondering if there is someone who knows their way around Nevow and Twisted who might be interested in doing some work in exchange for early equity in a startup. There are various ways we might do this - you could put something in place and hand it off, or get more involved if you like the project, or simply agree to talk things through, etc. While I can't give details about what's being built, I can say that I'm working in the area of information representation / dynamics, and also search. The application I'm beginning to build now relies on an architecture (already working) that I've already put nearly 3 years into thinking about and developing. I plan a release in early 2007. If you're curious, I've put a few links onto http://jon.es (bio, resume, odds & ends) that give some information about who I am. If no-one is interested, my second choice would be to pay someone as a consultant to spend some hours in skype listening to what I'm planning to do, and telling me what they think is the best way to go about it. I find some aspects of Nevow quite mysterious, and there are undoubtedly many things I should understand better about Twisted. Is anyone be interested in this? I hope this message wont seem lazy, or be deemed inappropriate for this list. My apologies if so. Regards, Terry

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