Mailman 3 August 2004 - Twisted-web

Test
by Philippe Lafoucrière 05 Aug '21

05 Aug '21

Hi all just a test

3 2

How to generate xhtml code with Resource.render?
by Krzystof Nowak 30 Aug '04

30 Aug '04

I have written a python's rpy script which generats a web page. All seems works fine, but for now I was playing with html. Now, I decided to upgrade to xhtml (I need a different namespaces, you will see below). I've have written an xhtml file: <?xml version="1.0" encoding="iso-8859-1"?> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:svg="http://www.w3.org/2000/svg"> <head></head><body> List <ul> <li>one</li> <li>two</li> </ul> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="10cm" height="10cm"> <svg:title> A two shapes</svg:title> <svg:g transform="scale(0.5)"> <svg:polygon style="fill:red; stroke:blue; stroke-width:10" points="350, 75 379,161 469,161 397,215 423,301 350,250 277,301 303,215 231,161 321,161"/> </svg:g> </svg:svg> </body></html> And it is working. But when I'm trying to generate this file by rpy script in this way: class Resource(resource.Resource): def render(self, request): request.write(''' <?xml version="1.0" encoding="iso-8859-1"?> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:svg="http://www.w3.org/2000/svg"> <head></head><body> List <ul> <li>one</li> <li>two</li> <li>three</li> </ul> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="10cm" height="10cm"> <svg:title> A two shapes</svg:title> <svg:g transform="scale(0.5)"> <svg:polygon style="fill:red; stroke:blue; stroke-width:10" points="350,75 379,161 469,161 397,215 423,301 350,250 277,301 303,215 231,161 321,161"/> </svg:g> </svg:svg> </body></html> ''') request.finish() return server.NOT_DONE_YET resource = Resource() browser dosent seem to understand that its xhtml code. I think I'm missing something very easy, maybe I'm not properly understand philosophy of xhtml or python.web. Do you know how to manage with this problem? (Sorry for my english :) ) Cheers Krzys

5 7

nevow - alternating row colors?
by angryhicKclown＠netscape.net 24 Aug '04

24 Aug '04

If I have a table, and I want the background colors to alternate, how would I do that in Nevow? __________________________________________________________________ Switch to Netscape Internet Service. As low as $9.95 a month -- Sign up today at http://isp.netscape.com/register Netscape. Just the Net You Need. New! Netscape Toolbar for Internet Explorer Search from anywhere on the Web and block those annoying pop-ups. Download now at http://channels.netscape.com/ns/search/install.jsp

5 4

Diagraming Twisted apps
by Sergio Trejo 22 Aug '04

22 Aug '04

I have truly enjoyed working with the Twisted Framework in recent weeks and have delved into Nevow, Atop, PB, and Twisted.web. I am creating an application with all of these components and am finding that my application is growing and becoming a bit complex. In order to keep track of the complexity of asynchronicity (deferreds, etc.), I am wondering what, if any, diagramming tools twisted developers use for designing visual schematics to accompany their projects? Are there any such programs that can parse code based on twisted which automatically generates visual representations of flows and logic? Has anyone tried using Dia? Serg _________________________________________________________________ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail

2 1

Error in my first test...
by Alessandro Barchi 19 Aug '04

19 Aug '04

Hi I try to write a very simple example with nevow. but I have this error, where I wrong? It seems that I cannot load the file alextest.py but the file exists! Thanks!! alex@mail:~/src/python/tests/nevow_samples/mysample0$ twistd -noy runapp.tac 2004/08/19 08:47 CEST [-] Log opened. 2004/08/19 08:47 CEST [-] twistd 1.3.0rc1 (/usr/bin/python2.3 2.3.4) starting up 2004/08/19 08:47 CEST [-] reactor class: twisted.internet.default.SelectReactor 2004/08/19 08:47 CEST [-] Loading runapp.tac... 2004/08/19 08:47 CEST [-] Traceback (most recent call last): 2004/08/19 08:47 CEST [-] File "/usr/lib/python2.3/site-packages/twisted/application/app.py", line 118, in getApplication 2004/08/19 08:47 CEST [-] application = service.loadApplication(filename, style, passphrase) 2004/08/19 08:47 CEST [-] File "/usr/lib/python2.3/site-packages/twisted/application/service.py", line 319, in loadApplication 2004/08/19 08:47 CEST [-] application = sob.loadValueFromFile(filename, 'application', passphrase) 2004/08/19 08:47 CEST [-] File "/usr/lib/python2.3/site-packages/twisted/persisted/sob.py", line 213, in loadValueFromFile 2004/08/19 08:47 CEST [-] exec data in d, d 2004/08/19 08:47 CEST [-] File "<string>", line 1 2004/08/19 08:47 CEST [-] import alextest 2004/08/19 08:47 CEST [-] ^ 2004/08/19 08:47 CEST [-] SyntaxError: invalid syntax 2004/08/19 08:47 CEST [-] Failed to load application: invalid syntax (line 1) 2004/08/19 08:47 CEST [-] Traceback (most recent call last): File "/usr/bin/twistd", line 36, in ? run() File "/usr/lib/python2.3/site-packages/twisted/scripts/twistd.py", line 184, in run app.run(runApp, ServerOptions) File "/usr/lib/python2.3/site-packages/twisted/application/app.py", line 205, in run runApp(config) File "/usr/lib/python2.3/site-packages/twisted/scripts/twistd.py", line 174, in runApp application = app.getApplication(config, passphrase) --- <exception caught here> --- File "/usr/lib/python2.3/site-packages/twisted/application/app.py", line 118, in getApplication application = service.loadApplication(filename, style, passphrase) File "/usr/lib/python2.3/site-packages/twisted/application/service.py", line 319, in loadApplication application = sob.loadValueFromFile(filename, 'application', passphrase) File "/usr/lib/python2.3/site-packages/twisted/persisted/sob.py", line 213, in loadValueFromFile exec data in d, d exceptions.SyntaxError: invalid syntax (line 1) Failed to load application: invalid syntax (line 1) 2004/08/19 08:47 CEST [-] barchi(a)roggeroetortia.it Poligrafico_Roggero_&_Tortia S.p.A. ------------------------------------------ Via Frejus 5 - 10092 Beinasco TO Italy Tel. +390113499222 - Fax +39 0113498866

2 2

nevow HTML based template fragment problem
by Tazzo 13 Aug '04

13 Aug '04

How can I insert a html rendered template inside another html rendered template? I mean, I have a rend.Page class with a docFactory that load a template (ex: page.html) with a header tag to renderize. The problem is that the header tag must be loaded from another rend.Page class who have is docFactory template (ex: header.html) to renderize, before send it. How can I use the header rend.Page class from a render method in another rend.Page class? -- Email.it, the professional e-mail, gratis per te: http://www.email.it/f Sponsor: Acquista ora Email.it Phone Card e comincia a risparmiare sulle tue telefonate! Clicca e scopri l'offerta Clicca qui: http://adv.email.it/cgi-bin/foclick.cgi?mid=2684&d=20040813

2 1

.htc behaviors
by Dominic Fox 12 Aug '04

12 Aug '04

Hi, As you may know, the current version of MSIE doesn't support the css :hover selector properly for elements other that <a>. There is a hack to fix this, which involves attaching an IE "behavior" to the document via CSS, as follows: body { behavior: url(csshover.htc); } and serving the csshover.htc file (which defines the behaviour using jscript) along with the .css and .htm files as static content. The hack is documented here: http://www.xs4all.nl/~peterned/csshover.html In order to get this to work with servers other than IIS, you need to set the MIME type for files with the .htc extension to be 'text/x-component', otherwise the behavior won't be loaded properly. This doesn't work using Twisted (specifically, using twisted.web.static.File to serve the page, stylesheet and behavior). You can serve the file, and you can set the MIME type by adding it to mimetypes.types_map, but the behavior still isn't loaded. One fix is to change the extension to something else, e.g. .htcHACK, and set the MIME type for that extension instead. That works OK. But why does it work, and why is it necessary? Is something else in Twisted deciding that all files with .htc extensions are Twisted documentation pages, and forcing the content type header back to text/html? curious, Dominic -- // Dream in black and white - // model cities, shooting up in the air

2 2

nested nevow:data?
by Jeff Bowden 10 Aug '04

10 Aug '04

Should it be possible to nest nevow:data declarations in a template? E.g. <html nevow:data="order" nevow:render="order"> <head><title>Order <nevow:slot name="order_number"/></title></head> <body> <h1>Order <nevow:slot name="order_number"/></h1> <ul nevow:data="order_items" nevow:render="sequence"> <li nevow:pattern="item" nevow:render="mapping"> ... slots and stuff </li> </ul> </body> When I do this I get a big long stack trace rooted in nevow/accessors.py. It works fine if I remove the outer nevow:data="order" (and dummy up a static fillSlots call for "order_number" in render_order). It also works if I remove the inner section. I can work around the problem by putting the nevow:data="order" declaration in multiple places but it would be handy if I didn't have to. Is this a bug or is it by design?

3 5

Cache-friendly Nevow pages
by Mary Gardiner 08 Aug '04

08 Aug '04

For some reason, it might be spending most of my time sitting at the end of a long thin piece of string connecting me to the rest of the universe, but it might also have been watching people pound on my RSS feeds every five minutes, I've been trying to write cache-friendly Nevow resources. This involves setting two HTTP headers, "Last-Modifed" and "ETag". At the moment I'm setting both of these headers using my data source (files in the file system). However, this has left me with a bit of a quandry about my docFactory templates. When my templates change, so should my Last-Modified and ETag headers. Otherwise clients using caches will see my old templates more or less indefinitely, at least on pages I don't subsequently change, because their conditional GET requests complete with correct If-Modified-Since and If-None-Match headers will tell the server never to send a fresh copy of the data. So, I'm faced with the problem of dating my templates or otherwise detecting when they change and I can't think of a good way. Some thoughts: 1. use file timestamps on the template files Pros: Fits OK with the way I deal with the rest of the website data Cons: Reduces flexibility. I can't think of a good way to do this with Stan templates. I also can't think of a good way to do this without restarting the server when my templates change. (I do currently do this, but would prefer not to.) 2. generate the ETag header based on a hash of page contents Pros: As best I can tell, this is how the ETag header is really meant to be generated, ideally it signals octect equality and should change if, for example, Nevow for some reason starts pretty-printing output. Cons: rend.Page.renderHTTP seems to make this really hard -- even if you set the bufferedflag = True, rend.Page.afterRender doesn't seem to have any way to access the result of the render. (Correct me if I'm wrong.) Also, this doesn't help with the Last-Modified date, which means I'm not helping HTTP/1.0 caches very much, unless I store the date the hash changed somewhere. 3. store the templates in some kind of object store and date-stamp them there. Pros: This might well let me change templates without restarting the server. Cons: It imposes a maintainence burden whereby I have to update the objet database with new templates. I like to have a copy of my website and templates on two different servers, and as best I can tell, no object database is going to like being copied to a remote server without me killing all associated processes on the remote server first, so there's a deployment problem. 4. hash the template so that a changed template means a changed hash Pros: This is probably nearly as good as hashing the page content, accuracy-wise. Cons: I don't have any idea how to hash a DocFactory object effectively. Hashing the DocFactory still leaves me vulnerable to changes in Nevow's rendering. Hashing the DocFactory won't tell me to update Last-Modified unless I store the date that the DocFactory changed somewhere. Anyone got any thoughts or has anyone solved this problem before? Help with implementing 2 (how do I get the page contents in order to hash them) or 4 (how can I hash a DocFactory object) also appreciated. -Mary

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