[mod_python] mod_python.publisher and Cheetah

Here is a better version of a handler which allows use of Cheetah
templates with mod_python.



from mod_python import apache

import os

# It is assumed that Apache config or .htaccess file
# blocks access to ".tmpl", ".py" and ".pyc" files.

def handler(req):

  # Assume REST style URLs. Ie., no extension is used
  # for accessing Cheetah pages. On this basis, first
  # perform a check that there is a ".py" file in
  # existance. This is done because can't distinguish
  # between a non existant module and a module which has
  # a coding error in it when using the function
  # "apache.import_module()". By returning DECLINED,
  # Apache will then serve up any static files in the
  # directory which may otherwise be matched.

  target = req.filename + ".py"

  if not os.path.exists(target):
    return apache.DECLINED

  # Grab the module name to look for from the last part
  # of the path. This means that pages can be spread
  # across subdirectories as well.

  directory,module_name = os.path.split(req.filename)

  # Import the module. Any coding error in the module
  # being imported is thrown back to the user. Error
  # also results if by chance the target just vanished.

  module = apache.import_module(module_name,[directory])

  # Ensure that there is a class defined in the module
  # of the appropriate name.

  if not hasattr(module,module_name):
    return apache.DECLINED

  # Create instance of the class and setup request object.

  tmpl = getattr(module,module_name)()
  tmpl.req = req

  # Assume that HTML is being generated.

  req.content_type = "text/plain"
  req.send_http_header()

  # Now generate the actual content and return it.

  req.write(tmpl.respond())

  return apache.OK



Graham Dumpleton wrote ..
> I somewhat suspect that you aren't going to get the code as by
> default generated by Cheetah to play well with publisher. As to
> your original custom handler, you could clean it up somewhat
> by using something like:
> 
> start = "/python/"
> 
> from mod_python import apache
> import string
> 
> def handler(req):
> 
>       req.content_type = "text/html"
>       module_name = string.replace (req.uri, start, "")
> 
>       #     try:
>       #              exec ("""import %s
>       #tmpl = %s.%s()
>       #tmpl.req = req""" % (module_name, module_name, module_name))
>       #     except ImportError:
>       #              return apache.HTTP_NOT_FOUND
> 
>       module = apache.import_module(module_name)
>       if not hasattr(module,module_name):
>             return apache.HTTP_NOT_FOUND
> 
>       tmpl = getattr(module,module_name)()
>       tmpl.req = req
> 
>       req.send_http_header()
>       req.write(tmpl.respond())
> 
>       return apache.OK
> 
> I still see some issues with this code in as much as I think it
> requires everything to be in the one directory. Ie., can't have
> subdirectories. Using "start" as a fixed value is not good, but
> that can also be fixed. Also, you can't mix different file types
> in the same directory.
> 
> When I get a chance, I'll write you a better version of this
> which would fix these problems and provide new abilities as well.
> I am surprised though that someone hasn't already written a
> better handler for integrating Cheetah with mod_python.
> 
> BTW, I am not on the Cheetah mailing list, so ensure any responses
> also go back to the mod_python list as well.
> 
> Graham
> 
> On Tuesday, March 15, 2005, at 02:17  AM, Stephane Bortzmeyer wrote:
> 
> > I always used Cheetah on Apache with a custom mod_python handler (see
> > http://wiki.cheetahtemplate.org/cheetahrecipes.html). I would like to
> > use mod_python's publisher
> > http://www.modpython.org/live/current/doc-html/hand-pub.html, in order
> > to limit my liability :-) specially for security reasons.
> >
> > It works fine but not if I use Cheetah's inheritance, as described in
> > http://www.cheetahtemplate.org/docs/users_guide_html_multipage/ 
> > inheritanceEtc.extends.html.
> > My foobar.tmpl Cheetah file is compiled as foobar.py, which includes
> a
> > foobar class. I added a index() routine but Cheetah puts in in the
> > foobar class, not directly in the foobar module. When
> > mod_python.publisher calls index(), it finds nothing and returns
> > NOT_FOUND.
> >
> >
> >
> > My SiteLogic.py:
> >
> >
> > from Cheetah.Template import Template
> >
> > class SiteLogic(Template):
> >         """ Pure Python class containing methods for the site """
> >
> >         # Never found because Cheetah puts it in a class
> >         def index(req):
> >             return "Dummy"
> >
> >
> >
> > My Site.tmpl:
> >
> >
> >
> > #from SiteLogic import SiteLogic
> > #extends SiteLogic
> > #implements respond
> >
> > #def title
> > No title #slurp
> > #end def
> >
> > #def body
> > <P>Default body.
> > #end def
> >
> > <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
> > <HTML>
> > <HEAD>
> > <TITLE>
> > $title
> > </TITLE>
> > </HEAD>
> > <BODY>
> > <H1>$title</H1>
> > $body
> > <HR>
> >
> >
> >
> > A typical page:
> >
> >
> > #from Site import Site
> > #extends Site
> > #implements body
> > #def title
> > Welcome
> > #end def
> >
> > <P>Some content.
> > _______________________________________________
> > Mod_python mailing list
> > Mod_python at modpython.org
> > http://mailman.modpython.org/mailman/listinfo/mod_python
> 
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