Mailman 3 May 2005 - Twisted-web

nested table sequences example
by Andrea Arcangeli 16 May '05

16 May '05

Hello, Before the weekend I asked some hint to dialtone on how to eliminate an huge cut-and-pasting in the template book of CPUShare. He quickly told me to use the IQ(ctx).patternGenerator to fill in the data for the tables. That was the information I needed to get on the right track and after some fighting (worst part to figure out was how to write the right currency in the header) I got it working. Resulting html is exactly the same, but rendering time is down from 600msec to 250msec and more important there's no code duplication in the rendering and template anymore. I'm willing to share this code for nevow documentation purposes just in case anybody else has similar needs, since I didn't see examples covering nested tables usages like this yet. This below is the template. Before the weekend it was 532 lines (I was using only many n:data="xx" and n:render="sequence", with many different perspective calls). It was a nightmare to maintain, every time I wanted to do a cosmetical change, I had to cut-and-paste it 5 times all over the >500 lines file. Now after this cleanup the same template is down to 103 lines: <n:invisible xmlns:n="http://nevow.com/ns/nevow/0.1"> <table class="book_outside" n:data="book" n:render="book_composite"> <table class="account" n:pattern="book_sequence_bid" n:render="book_sequence"> <n:invisible n:pattern="header" n:render="book_header"> <caption class="book"> <n:slot name="currency" /> Bid </caption> <tr class="account"> <th class="account">Price</th> <th class="account">Time</th> <th class="account">Size</th> <th class="account">MFLOPS</th> <th class="account">RTT</th> <th class="account">RAM</th> <th class="account">CPUCoins</th> </tr> </n:invisible> <tr class="account" n:pattern="item" n:render="book_bid"> <td class="account_right"><pre class="book_right"><n:slot name="price" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="time" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="size" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="mflops" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="rtt" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="ram_mbytes" /></pre></td> <td class="account_right"><pre class="book_center"><n:slot name="cpucoins" /></pre></td> </tr> <tr class="account" n:pattern="item" n:render="book_bid"> <td class="account_right_even"><pre class="book_right"><n:slot name="price" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="time" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="size" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="mflops" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="rtt" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="ram_mbytes" /></pre></td> <td class="account_right_even"><pre class="book_center"><n:slot name="cpucoins" /></pre></td> </tr> <tr class="account" n:pattern="empty"> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> </tr> </table> <table class="account" n:pattern="book_sequence_ask" n:render="book_sequence"> <n:invisible n:pattern="header" n:render="book_header"> <caption class="book"> <n:slot name="currency" /> Ask </caption> <tr class="account"> <th class="account">Price</th> <th class="account">Time</th> <th class="account">MFLOPS</th> <th class="account">RTT</th> <th class="account">RAM</th> <th class="account">CPUCoins</th> <th class="account">Arch</th> </tr> </n:invisible> <tr class="account" n:pattern="item" n:render="book_ask"> <td class="account_right"><pre class="book_right"><n:slot name="price" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="time" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="mflops" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="rtt" /></pre></td> <td class="account_right"><pre class="book_right"><n:slot name="ram_mbytes" /></pre></td> <td class="account_right"><pre class="book_center"><n:slot name="cpucoins" /></pre></td> <td class="account_right"><pre class="book_center"><n:slot name="arch" /></pre></td> </tr> <tr class="account" n:pattern="item" n:render="book_ask"> <td class="account_right_even"><pre class="book_right"><n:slot name="price" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="time" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="mflops" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="rtt" /></pre></td> <td class="account_right_even"><pre class="book_right"><n:slot name="ram_mbytes" /></pre></td> <td class="account_right_even"><pre class="book_center"><n:slot name="cpucoins" /></pre></td> <td class="account_right_even"><pre class="book_center"><n:slot name="arch" /></pre></td> </tr> <tr class="account" n:pattern="empty"> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> <td class="account_dashed">-</td> </tr> </table> </table> </n:invisible> And this is the rendering code: BOOK_SIZE = 10 BOOK_TIME_STRFTIME = '%y%m%d %H:%M:%S' class book_content_class(rend.Fragment): docFactory = loaders.xmlfile('book.xml', templateDir = XMLDIR, ignoreDocType = True) def data_book(self, ctx, data): try: return IPB(ctx).call('get_books', BOOK_SIZE) except AttributeError: return [] def render_book_composite(self, ctx, data): ptrn_bid = inevow.IQ(ctx).patternGenerator('book_sequence_bid') ptrn_ask = inevow.IQ(ctx).patternGenerator('book_sequence_ask') return ctx.tag[[ tags.tr(_class="book_outside") [tags.td(_class="book_outside")[ptrn_bid(data=(x[0], x[1]))], tags.td(_class="book_outside")[ptrn_ask(data=(x[0], x[2]))]] for x in data ]] def render_book_sequence(self, ctx, data): 'This is the same as "sequence" but uses data[1] instead of data' tag = ctx.tag headers = tag.allPatterns('header') pattern = tag.patternGenerator('item') divider = tag.patternGenerator('divider', default=tags.invisible) content = [(pattern(data=element), divider(data=element)) for element in data[1]] if not content: content = tag.allPatterns('empty') else: ## No divider after the last thing. content[-1] = content[-1][0] footers = tag.allPatterns('footer') return tag.clear()[ headers, content, footers ] def render_book_header(self, ctx, data): ctx.fillSlots('currency', data[0]) return ctx.tag def render_book_ask(self, ctx, data): ctx.fillSlots('price', data[0]) ctx.fillSlots('time', time.strftime(BOOK_TIME_STRFTIME, time.localtime(data[1]))) ctx.fillSlots('mflops', data[2]) ctx.fillSlots('rtt', data[3]) ctx.fillSlots('ram_mbytes', data[4]) ctx.fillSlots('cpucoins', data[5]) ctx.fillSlots('arch', data[6]) return ctx.tag def render_book_bid(self, ctx, data): ctx.fillSlots('price', data[0]) ctx.fillSlots('time', time.strftime(BOOK_TIME_STRFTIME, time.localtime(data[1]))) ctx.fillSlots('size', data[2]) ctx.fillSlots('mflops', data[3]) ctx.fillSlots('rtt', data[4]) ctx.fillSlots('ram_mbytes', data[5]) ctx.fillSlots('cpucoins', data[6]) return ctx.tag The list returned by the get_books perspective client, is created by the pb server like this: [[currency1, [bidsequence], [asksequnce]], [currency2, [bidsequence], [asksequence]],...]. You can see that I had to create my own render_book_sequence that works exactly like the default render_sequence, except that uses "data[1]" instead of "data". I didn't find any other way than to create my own render_book_sequence, to be able to fill in the currency information in render_book_header. Hope this helps!

1 0

_nevow_carryover_
by Paul Moore 14 May '05

14 May '05

Can someone tell me what the _nevow_carryover_ argument that gets added to URLs as part of form processing is for? Is there any way of suppressing it (and presumably handling the functionality in an alternative way)? It looks session-related, but if I delete it and re-enter the base URL, there seems to be no difference. I've looked at the source code, but it baffles me :-( Is it another of these redirect loop hacks, like __start_session__? Paul. -- There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened. -- Douglas Adams

4 4

NamedAnyError
by Andrea Arcangeli 10 May '05

10 May '05

I'm getting these errors: 2005/05/06 00:45 CEST [-] NamedAnyError: <function FunctionSerializer at 0x2aaaae6c6b18> stackless.function 2005/05/06 00:45 CEST [-] NamedAnyError: <function MethodSerializer at 0x2aaaae6c6c08> stackless.instancemethod 2005/05/06 00:45 CEST [-] NamedAnyError: <function URLSerializer at 0x2aaaae5d4500> nevow.url.URLPath Is this only a debugging print?

6 13

appropriate way to use patternGenerator
by Carl Shimer 09 May '05

09 May '05

Hi, I spent the last couple of hours trying to get the nevow LivePage stuff to work. The problem was on this line of my code: Inevow.IQ(self.docFactory).patternGenerator('foo') After a big of debugging (well, a lot of debugging) I figured out that the problem was that my stan tree (self.docFactory) wasn't fully complete, rather due to my setup it contained functions that weren't evaluated yet. patternGenerator() would fail because foo wasn't defined yet - it would be defined later (perhaps after the page was rendered?) Anway, my work around was to do this: Inevow.IQ(self.tagfragments()).patternGenerator('foo') where tagfragments() returns a partial stan tree. Questions: 1) my solution seems like a hack :) is there a way I can run patternGenerator on the fully evaluated tree? 2) The way I am doing code reuse is via inheritance. The parent object (derived from rend.Page) has all the code for common elements like the page header, doctype, and the docFactory. The docFactory embeds a number of entry points which may later overridden by a derived class. So the child page always overrides the content() function to render the main body of the page. Is the appropriate mechanism? I read somewhere about the Fragment class but didn't quite understand it. Thanks, Carl

2 2

nested nevow:data
by Little 09 May '05

09 May '05

How can i use nested nevow:data construction? <div n:data="items"> ... <div n:data="subitems"> </div> </div> this construction won't working at all... For example, first data is array of years ('1997', '1998', e.t.c) and second data is "select * from .. where year=%s" And i whant a page with many tables - one table, one year So i desided to make nested n:data tags: <div n:data="years" n:render="years"> <div n:pattern="year"> <table> <div n:data="year" n:render="year" > <div n:pattern="item"> tr td td td </div> </div> </div> But it doesn't work Any solution?

2 1

Shell commands on Windows XP
by Ryan, Adam 04 May '05

04 May '05

I'm new to twisted, on a Windows XP box, reading through the documentaion, and not sure how to use the shell commands. I tried opening twistenv.bat and running mktap but I'm missing something. I get: -:- -:- -:- -:- -:--:- -:- -:- -:- -:--:- -:- -:- -:- -:- Commands available in twisted: twistd mktap manhole tapconvert ckeygen trial coi l lore websetroot -:- -:- -:- -:- -:--:- -:- -:- -:- -:--:- -:- -:- -:- -:- C:\>mktap 'mktap' is not recognized as an internal or external command, operable program or batch file. Any help to get me started would be great. Cheers, Adam Ryan

3 2

RE: [Twisted-web] Shell commands on Windows XP
by Ryan, Adam 04 May '05

04 May '05

You're right... > -----Original Message----- > From: Dan Shidlovsky [mailto:dddwd@gala.net] > Sent: Wednesday, May 04, 2005 11:04 AM > To: Discussion of twisted.web, Nevow, and Woven > Subject: Re: [Twisted-web] Shell commands on Windows XP > > > > and running mktap but I'm missing something. > > Seems you have passed reading the documentation. > > http://twistedmatrix.com/projects/core/documentation/howto/plugin.html > > > _______________________________________________ > Twisted-web mailing list > Twisted-web(a)twistedmatrix.com > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-web >

1 0

livepage
by Christopher Zorn 03 May '05

03 May '05

Hey, I was using livepage through a proxy. I had to make a small change to get it to work, I just want to let you guys know. def render_liveglue(self, ctx, data): #return tags.script(src=url.here.child('nevow_glue.js')) return tags.script(src='nevow_glue.js') url.here gave the url that was on the server behind the firewall.

6 9