On 18 Dec 2005 12:27:55 -0800, [EMAIL PROTECTED] wrote: >Hi Jean-Paul, > >I am a bit lost in you code. Is it possible for you to step through >it?
For in depth-assistance, it would probably be best to continue on [EMAIL PROTECTED] You might also want to check out some of the links on <http://divmod.org/trac/wiki/DivmodNevow>. There is also a friendly, helpful IRC channel on freenode: #twisted.web. I'll give a brief overview of what's going on, though: from nevow import rend, loaders, tags # Subclass rend.Page - this is the base class for pretty # much anything that represents an entire HTTP Resource class NewsIndex(rend.Page): # Set the template for this page. Since it's just a # throw-away example, use some really cheesy stan (the # stuff with the square brackets). The below template # turns into something like # <html><body>[whatever render_index returns]</body></html> docFactory = loaders.stan(tags.html[ tags.body(render=tags.directive('index'))]) # Boring initializer that takes a database connection # pool to issue queries against. def __init__(self, connpool): super(NewsIndex, self).__init__() self.connpool = connpool # "model" function - doesn't know about web, just # knows the db schema; returns a Deferred that fires # with information about all the articles in the database. def _retrieveIndex(self): return self.connpool.runQuery( "SELECT articleId, articleTitle, articleImage FROM articles") # Another model function. This one gets the body text for # one particular article. def _retrieveArticle(self, articleId): return self.connpool.runQuery( "SELECT articleBody FROM articles WHERE articleId = ?", (articleId,)) # The render function for the guts of the index page. This # uses one of the model functions to get all the articles in # the database. Since _retrieveIndex returns a Deferred, it # doesn't use the results right away - instead of defines a # lambda that will get invoked with the article information # when it is received. # There's some display logic here, too. Some more stan, which # renders to something like: # <div> # <a href="<articleID>"> # <img src="<article image>" /> # article title # </a> # </div> # for each article in the index def render_index(self, ctx, data): return self._retrieveIndex().addCallback(lambda index: ctx.tag[[ tags.div[ tags.a(href=articleID)[ tags.img(src=articleImage), articleTitle]] for (articleID, articleTitle, articleImage) in index]]) # Allow this Resource to have children. Above, we generated links # to "articleID" for each article in the index. This function # handles those links by using the other model function to retrieve # the body of the requested article and return another Page subclass # instance for it. def childFactory(self, ctx, name): return self._retrieveArticle(name).addCallback(lambda articleBody: ArticlePage(articleBody)) # The other display class. This one is pretty boring. It just # displays the body of an article. class ArticlePage(rend.Page): docFactory = loaders.stan(tags.html[ tags.body(render=tags.directive('article'))]) def __init__(self, articleBody): super(ArticlePage, self).__init__() self.articleBody = articleBody # Just spit out the article body. Note I changed one thing here. # In the original version, I left out the "ctx.tag[...]" around # the article body. This would have removed the <body> tag from # the resulting document! Ooops. I also left this out of # render_index above (so I've added it there as well). def render_article(self, ctx, data): return ctx.tag[self.articleBody] from twisted.enterprise import adbapi # Whatever DB-API 2.0 stuff you want cp = adbapi.ConnectionPool('pypgsql', ...) from twisted.application import service, internet from nevow import appserver application = service.Application("News Site") webserver = appserver.NevowSite(NewsIndex(cp)) internet.TCPServer(80, webserver).setServiceParent(application) # Run with twistd -noy <whatever you name this file> Hope this helps, Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
