[mod_python] Which hadler to use

On 26/12/2006, at 11:27 PM, Maksim Kasimov wrote:

> Hi,
>
> i have similar problem as was posted earlier "Protecting Image- 
> Directory's with PythonAccessHandler" - i need to allow users to  
> load content (images, audio, games ...)
>
> doing that, i make the decision using information stored in Request  
> object (headers: User-Agent, client IP and some prameters in query  
> string).
>
> For example, url can looks like this:
>          http://myserver.com/download.py/1234567890
>          (1234567890 - is the key, that must be converted to an  
> actual file name if it's allowed)
>
> all information that needed, available from all handlers - as i can  
> see, Request do not mutate when passing through all handlers (i  
> might be wrong)

If mod_rewrite is being used, then certain request attributes can be  
modified
on the way through. :-)

> my question is: which handler to use( PythonInitHandler,  
> PythonPostReadRequestHandler, PythonHeaderParserHandler,  
> PythonTransHandler or PythonAccessHandler as was mentioned in  
> "Protecting Image-Directory's with PythonAccessHandler" thread) ?
>
> Are there some rules on how to correctly choose Python*Handler (at  
> least in my case)?

You can find a description of what the various Apache phases are for at:

   http://apache.hpi.uni-potsdam.de/document/ 
4_4Request_Response_Loop.html
   http://www.kuzbass.ru/docs/apache_c_mod_perl/24.htm#subhead_2

Even the mod_python documentation in the description of each handler
directive gives a brief statement about what each is for.

In short though use an access handler to control which client hosts can
access a resource. Use an authen handler to control whether a user can
access an area and use an authz handler to control where a user can
access specific resources.

The mapping of an ID in a URL can be performed by your response
handler with it using req.sendfile() to send an actual file which is  
stored
separately under some other name.

Graham