Mailman 3 June 2007 - Twisted-web

Test
by Philippe Lafoucrière 05 Aug '21

05 Aug '21

Hi all just a test

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Re: [Twisted-web] Best way to serve up XML
by Dav Clark 26 Jun '07

26 Jun '07

So, first off - I'm new to Twisted. I've done mostly Zope & lxml + the standard libs for my "web" needs until I got involved in a crazy project that _needs_ an event loop. My initial reaction is that there's no right answer to your question without more detail. I'm just getting started, but Stan provides excellent facilities for loading in XML files and then composing them, including the ability to create templates. I don't like transcoding - the easiest way to see if your code will generate the XML you want is if your code _is_ the XML you want. This is probably the best place to read about this method: http://divmod.org/users/mg/nevow-doc/nevow-xml-templates.html These XML templates are pretty well self-documenting, and can be easily edited by anyone with a basic understanding of XML. If you want to use a pure python solution, and you don't want to use Stan, I'd second a vote for ElementTree. This also provides an easy migration path to Martjin Faasen's (sp?) blazing fast (and otherwise generally awesome) lxml package: http://codespeak.net/lxml/ Cheers, Dav Clark 917-544-8408 > From: "Nicholas Milkovits" <nmilkovits(a)gmail.com> > Subject: [Twisted-web] Best way to serve up XML > ...what other twisted users think 1) is the most maintainable approach > 2) what method has the most stable supporting libs and 3) is the > fastest. On > average the XML documents will be small but could potentially grow > to a > considerable size. Any comments or insights are appreciated. Dav Clark 917-544-8408

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Best way to serve up XML
by Nicholas Milkovits 25 Jun '07

25 Jun '07

Hello all, I am working on my first twisted app which is a set of restful services that return xml to the consumers. When it comes to generating the XML it seems like there are a lot of solutions (i.e. building it manually using xml.dom.minidom, woven, nevow + stan, sux, microdom). I wanted to get an idea of what other twisted users think 1) is the most maintainable approach 2) what method has the most stable supporting libs and 3) is the fastest. On average the XML documents will be small but could potentially grow to a considerable size. Any comments or insights are appreciated. -Nick M.

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FCKEditor integration
by Simon Hedberg 25 Jun '07

25 Jun '07

Hi, I'm starting up some work where I plan to use the FCKEditor[1] but before I start I'd like to know if perhaps anyone has already done a File Browser Connector[2] based on Nevow? Best regards, Simon H [1] http://www.fckeditor.net [2] http://fckeditor.wikiwikiweb.de/Developer's_Guide/Participating/Server_S ide_Integration#Browser

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Web development using Twisted
by Daniel de la Cuesta 21 Jun '07

21 Jun '07

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Re: [Twisted-web] Obvious stuff... just not to me, re: Failure to Install...
by Dav Clark 19 Jun '07

19 Jun '07

First off, thanks for answering my e-mail so thoroughly! I even had a lightbulb moment with your "nevow/plugins is just a directory" comment (though now I'm thinking "but why does it use an __init__.py then?" - but I'm letting it go for now). As for your questions, I attempt to answer below. On Jun 18, 2007, at 12:00 PM, Jean-Paul Calderone wrote: > setup.py is basically fully supported. If you find bugs in it, we > will do > our best to fix them. easy_install isn't really supported at all; > please > don't suggest it or anything related to setuptools. Got it - I guess the failure to install javascripts really is a "real" bug then... but I've reported it already. >> 3a) So, for example, after getting the thing working with the stock >> nevow/plugins directory, I standardized on having a local nevow/ >> plugins >> directory as a sibling of my tac file. I would suggest this be the >> recommended (or at least an alternative) method described in the >> wiki - >> this keeps all example files bundled under the same root dir. >> This also >> allows the possibility of bundling a tar or zip of an athena >> package, you >> un-archive it, and the example just works with twistd -ny >> example.tac from >> where it sits. (well, you need to alter the /path/to/your/file to >> sibpath(__file__, 'mymodule.js')). > > I'm not totally clear on what you're suggesting here. As described > on the > wiki, the plugin system does let you keep all of your source files > beneath > one directory. Maybe I'm not understanding your concern, or maybe > you're > still missing something about how plugins work. Could you describe > this > issue further? An example is probably more useful. I've put something here for you: http://www.keepopen.com/files/athena-example.tar.bz2 You can just un-archive that and immediately run `twistd -ny myelement.tac` (and you can check those files with a quick diff against the default Athena tutorial files to see the very few changes - basically those described above). Anyway, I'll admit that you're not forced to learn as much my way! >> 3b) I would go a step further and suggest that, as in zope, a way to >> create "instances" be created. This would just mean populating a >> directory >> with things like a plugins direcotry, a js dir for >> nevow.athena.autoJSPackage to load and other stuff I haven't >> learned about >> yet. A set of scripts localized for that instance would add the >> appropriate root to the python path before running. Or, you >> could just >> require people to run twistd from the root dir of the bundle. >> This would >> be remarkably similar to the "solution" for 3a. > > Requiring extra programs in order to run the actually interesting > program > doesn't interest me very much. Beyond this, I'm not really sure > how this > suggestion differs much from the current system, except that it > explicitly > makes environment setup something that goes into a helper script, > rather > than relying on each user to have an environment which is "correctly" > configured. Perhaps the documentation should go into more detail > about > what Nevow considers a "correct" environment? Agreed - maybe some of the "agreed" changes to the wiki will go some way towards this. I was thinking of something more like a helper script. But I'm beginning to understand that if you're using twisted, you're probably doing something complicated... so you should probably think about things before you do them :) Maybe an environment recipe collection would be nice. >> 3d) Speaking of strange .js includes, some system (correctly?) >> associates >> the nevow/empty.js file with most Nevow classes. But for root >> classes, you >> also get these __init__.js associations, which are non-existent >> *.js files. >> Is this a bug? > > Hmm, could be. Can you describe this further? -- import nevow.athena jsd.getModuleForName('MyModule') # or whatever print jsd.mapping -- yeilds (among many other things): { ...... u'Divmod': '/Users/dav/Desktop/SecurMe/dev/Nevow/nevow/js/Divmod/ __init__.js', u'Divmod..svn': '/Users/dav/Desktop/SecurMe/dev/Nevow/nevow/empty.js', u'Divmod..svn.prop-base': '/Users/dav/Desktop/SecurMe/dev/Nevow/nevow/ empty.js' .....} These "empty.js" files occur if and only if we're mapping to a .svn directory. So, I guess this is just a side-effect of my using a svn checkout. But it's still weird. That emtpy.js file does exist - it's empty. The __init__.js entries refer to non-existent files. >> 5) Why do all examples have twistd -noy, when -y implies -o? >> > > Historic reasons. The people writing these wiki pages probably > still have > finger memory from before -y implied -o. :) Feel free to fix this. I see no need to remove history! Thanks again, Dav

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Obvious stuff... just not to me, re: Failure to Install...
by Dav Clark 17 Jun '07

17 Jun '07

I'm slowly beginning to wrap my head around Nevow. For one, while it's not explicit anywhere, it seems really clear that the intention is simply to add the Nevow root directory to your python path. In my case, I'm using the easy_install develop workaround: python -c "import setuptools; execfile('setup.py')" develop from the .../Nevow path. This means I can svn update, and that version is working without any more reinstalls. In addition, I got thrown for a loop with the Athena tutorial, because it suggests that to understand the Nevow plugin search system, you should just look at the Twisted plugin search system. This had me with a custom <emph>twisted</emph>/plugins directory, and using pdb to step through code to see why it wasn't getting loaded by Nevow, when clearly the Twisted plugin system was populating this with the normal 'dropin.cache' and soforth. But now I understand that the nevow/plugins and the twisted/plugins are similarly handled but distinct repo's. So, while I have a borderline unhealthy desire to learn twisted & nevow, and will work through this stuff, I recon a lot of people might have a look and say, "WTF!" and go to Django or something. I'd like to help fix the documentation as I learn, but I don't want to write the wrong thing either. So, here are some changes I would make if OK to the Nevow and Athena docs on the Wiki: 1) This is the only obviously wrong thing - on the Athena page, it says that you should install modules into a plugin directory under Nevow instead of nevow. This is confusing and had me creating a Nevow/plugins directory in my private PYTHONPATH (which makes sense at first, as there is a Nevow directory as well as a nevow directory if you checkout from svn). 2) Modify the Nevow install instructions to explain that neither ./ setup.py install or easy_install are fully supported. Suggest easy_install develop or similar as preferred alternative, outright copying or adding the Nevow direcotry to your PYTHONPATH as a secondary (as well as setting up scripts somewhere in your PATH). I would just fix the install to work properly, but I'm not sure what would be "right" more on that below. 3) Regarding, e.g. javascript plugins, it seems that the convention is to install both user and 3rd party packages into the nevow package. This is very different than what most people are used to, but quite similar to the way e.g. an in-place Zope install behaves (particularly if you are doing an in-place install as I describe above). I don't like doing this - as it moves me away from a clean separation of "my" code from "your" code. 3a) So, for example, after getting the thing working with the stock nevow/plugins directory, I standardized on having a local nevow/ plugins directory as a sibling of my tac file. I would suggest this be the recommended (or at least an alternative) method described in the wiki - this keeps all example files bundled under the same root dir. This also allows the possibility of bundling a tar or zip of an athena package, you un-archive it, and the example just works with twistd -ny example.tac from where it sits. (well, you need to alter the /path/to/your/file to sibpath(__file__, 'mymodule.js')). 3b) I would go a step further and suggest that, as in zope, a way to create "instances" be created. This would just mean populating a directory with things like a plugins direcotry, a js dir for nevow.athena.autoJSPackage to load and other stuff I haven't learned about yet. A set of scripts localized for that instance would add the appropriate root to the python path before running. Or, you could just require people to run twistd from the root dir of the bundle. This would be remarkably similar to the "solution" for 3a. 3c) I'm still a bit unclear on how python deals with identically named packages in different directories in the path. So, for example, I know have two nevow/plugins directories on my path. Everything seems to work fine, and indeed, the athena.JSDependencies seems to be able to find files from both. Even if I add an __init__.py file to my own nevow/plugins directory, the autoJSPackage call from the default nevow/plugins/__init__.py seems to fire correctly. But at some point, name collisions are necessarily going to be a problem. I could see some _very_ funny errors arising from this, e.g. if the python interpreter simply uses the first file it finds, it could load a .py file from one directory, then load an __init__.py file from another directory which overrides the objects loaded from that first .py file... pointers would be appreciated on this. 3d) Speaking of strange .js includes, some system (correctly?) associates the nevow/empty.js file with most Nevow classes. But for root classes, you also get these __init__.js associations, which are non-existent *.js files. Is this a bug? 4) Perhaps have a page describing Divmod wiki etiquette... answering the question of this e-mail, which is "How liberal should I be in editing the Wiki(s)?" 5) Why do all examples have twistd -noy, when -y implies -o? Anyway, as I've said, I'd like to leave some breadcrumbs for those right behind me before I forget what it's like to be such a noob! Any feedback or guidance on appropriate help is appreciated. In particular, how I should proceed now and in future with Wiki / documentation edits. Cheers, Dav Clark 917-544-8408 Dav Clark 917-544-8408

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Installation problem? Missing Interface
by Mike Kenny 16 Jun '07

16 Jun '07

Hi, I have installed Twisted-2.5.0 and the zope.interface-3.3.0 that comes with this package. I then tried to follow some introductory steps on the web site and downloaded the simple.py example. When I execute 'twistd -ny simple.py' I obtain the output below informing me that I am missing Interface. Everything seems to be installed correctly. Is there some simple step I have overlooked? Thanks 2007/06/16 11:14 +0200 [-] Log opened. 2007/06/16 11:14 +0200 [-] twistd 2.5.0 (/usr/bin/python 2.5.1) starting up 2007/06/16 11:14 +0200 [-] reactor class: <class 'twisted.internet.selectreactor.SelectReactor'> 2007/06/16 11:14 +0200 [-] Loading simple.py... 2007/06/16 11:14 +0200 [-] Traceback (most recent call last): 2007/06/16 11:14 +0200 [-] File "/usr/lib/python2.5/site-packages/twisted/application/app.py", line 218, in getApplication 2007/06/16 11:14 +0200 [-] application = service.loadApplication(filename, style, passphrase) 2007/06/16 11:14 +0200 [-] File "/usr/lib/python2.5/site-packages/twisted/application/service.py", line 341, in loadApplication 2007/06/16 11:14 +0200 [-] application = sob.loadValueFromFile(filename, 'application', passphrase) 2007/06/16 11:14 +0200 [-] File "/usr/lib/python2.5/site-packages/twisted/persisted/sob.py", line 215, in loadValueFromFile 2007/06/16 11:14 +0200 [-] exec fileObj in d, d 2007/06/16 11:14 +0200 [-] File "simple.py", line 1, in <module> 2007/06/16 11:14 +0200 [-] from twisted.web2 import server, http, resource, channel 2007/06/16 11:14 +0200 [-] File "/usr/lib/python2.5/site-packages/twisted/web2/server.py", line 25, in <module> 2007/06/16 11:14 +0200 [-] from twisted.web2 import http, iweb, fileupload, responsecode 2007/06/16 11:14 +0200 [-] File "/usr/lib/python2.5/site-packages/twisted/web2/http.py", line 27, in <module> 2007/06/16 11:14 +0200 [-] from twisted.web2 import iweb 2007/06/16 11:14 +0200 [-] File "/usr/lib/python2.5/site-packages/twisted/web2/iweb.py", line 58, in <module> 2007/06/16 11:14 +0200 [-] class IOldNevowResource(components.Interface): 2007/06/16 11:14 +0200 [-] AttributeError: 'module' object has no attribute 'Interface' 2007/06/16 11:14 +0200 [-] Failed to load application: 'module' object has no attribute 'Interface' 2007/06/16 11:14 +0200 [-] Unhandled Error Traceback (most recent call last): File "/usr/lib/python2.5/site-packages/twisted/application/app.py", line 379, in run runApp(config) File "/usr/lib/python2.5/site-packages/twisted/scripts/twistd.py", line 23, in runApp _SomeApplicationRunner(config).run() File "/usr/lib/python2.5/site-packages/twisted/application/app.py", line 157, in run self.application = self.createOrGetApplication() File "/usr/lib/python2.5/site-packages/twisted/application/app.py", line 207, in createOrGetApplication application = getApplication(self.config, passphrase) --- <exception caught here> --- File "/usr/lib/python2.5/site-packages/twisted/application/app.py", line 218, in getApplication application = service.loadApplication(filename, style, passphrase) File "/usr/lib/python2.5/site-packages/twisted/application/service.py", line 341, in loadApplication application = sob.loadValueFromFile(filename, 'application', passphrase) File "/usr/lib/python2.5/site-packages/twisted/persisted/sob.py", line 215, in loadValueFromFile exec fileObj in d, d File "simple.py", line 1, in <module> from twisted.web2 import server, http, resource, channel File "/usr/lib/python2.5/site-packages/twisted/web2/server.py", line 25, in <module> from twisted.web2 import http, iweb, fileupload, responsecode File "/usr/lib/python2.5/site-packages/twisted/web2/http.py", line 27, in <module> from twisted.web2 import iweb File "/usr/lib/python2.5/site-packages/twisted/web2/iweb.py", line 58, in <module> class IOldNevowResource(components.Interface): exceptions.AttributeError: 'module' object has no attribute 'Interface' Failed to load application: 'module' object has no attribute 'Interface' 2007/06/16 11:14 +0200 [-]

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disabling redirection
by Markus Schiltknecht 15 Jun '07

15 Jun '07

Hi, I'm having problems with reverse proxies and twisted web / nevow. Which one does the redirection, in case the host or port doesn't match? How can I disable that? I want twisted to simply serve the URL it's given and not do anything fancy with the Host: header. Sorry if that sounds to harsh, I'm simply frustrated and could use some help... Regards Markus

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Failure to install javascripts in Nevow
by Dav Clark 15 Jun '07

15 Jun '07

Hi all, So, I'm just getting started, so please forgive any rampant noob-ness on my part. But, the problem is simple - there doesn't seem to be any logic anywhere to install the .js files in the nevow directory for either the traditional or setuptools method of installing Nevow. I can copy these files into the site-python/nevow directory no problem, but this seems to defeat the notion of an install script. Or am I missing something? If not, I'm happy to file a bug report. Cheers, Dav Clark Dav Clark 917-544-8408

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