Re: [Cheetahtemplate-discuss] Template object caching in webware

[<ir...@ms...>]

On Mon, Nov 05, 2001 at 08:38:01AM -0800, Mike Orr wrote:
> On Mon, Nov 05, 2001 at 09:48:40AM -0500, Aaron Held wrote:
> > In every servlet I currently have something like
> > 
> >   tf='ViewUser.ctd'
> >   templateFile=os.path.join(os.path.dirname(self.serverSidePath()),'templates',tf)
> >   t = Template(file=templateFile,searchList=[{'user':userToView}])
> >   self.writeln(t)
> > 
> > So I guess that my template object is recreated from the file each time.
> > 
> > Is there any way to create a template in a module and then reuse it with a different namelist?
> > 
> > Something like=
> >   tf=LoadedTemplatesModules.ViewUser
> >   t = Template(tf,searchList=[{'user':userToView}])
> >   self.writeln(t)
> 
> First I'll describe the general way, and then something that might be
> more applicable to your situation.  Generally:
> 1) Place all your templates in *.tmpl files
> 2) Run 'cheetah-compile' on them all.  This creates same-name modules *.py .
> 3) Request the *.py files on the web.  Cheetah and Webware will take
> care of caching and reusing the servlets and templates.
> 
> For your situation, you could try a template cache dictionary.  Create a
> module with this code, or put it in an existing application module:

Actually, you'd have to do it slightly differently than this.  The code
below is suitable for creating a template from a *.tmpl file directly
(assuming constructTemplatePath() returns the path with ".tmpl"
extension).  

It may be easier in your case to just to it this way and skip the 
cheetah-compile step.  To actually use compiled *.py templates, you'd
somehow have to put the uri directory in sys.path (if you have 
templates in multiple directories), import it, create a template object
using the dynamic module name and class name appropriate to this
request, worry about same-name templates in different directories which
Python will refuse to "reimport" (reload() might have undesired side
effects), and then *finally* you'll have your template object to store
in the pool.

> 	# poolModule.py
> 	_pool = {}
> 	def getTemplate(uri):
> 		try:
> 			return _pool[uri]
> 		except KeyError:
> 			path = constructTemplatePath(uri)
> 			t = Template(file=path)
> 			_pool[uri] = t
> 
> Then in your servlets:
> 
> 	import poolModule
> 	t = poolModule.getTemplate(uri)
> 	t.user = userToView
> 	self.writeln(t)
> 	
> Of course, the last two statements are thread-unsafe because another 
> thread might change t.user between them.  If simultaneous
> use is a possibility, you'll have to give each template a mutex, spawn
> an additional template if one is in use, wait till that one's finished,
> or have a separate pool for each thread.
> 
> -- 
> -Mike (Iron) Orr, ir...@ms...  (if mail problems: ms...@ji...)
>    http://iron.cx/     English * Esperanto * Russkiy * Deutsch * Espan~ol
> 
> _______________________________________________
> Cheetahtemplate-discuss mailing list
> Che...@li...
> https://lists.sourceforge.net/lists/listinfo/cheetahtemplate-discuss

-- 
-Mike (Iron) Orr, ir...@ms...  (if mail problems: ms...@ji...)
   http://iron.cx/     English * Esperanto * Russkiy * Deutsch * Espan~ol