[Web-SIG] Standardising containment.

[Alan Kennedy]

[Alan Kennedy]
>> The other main one that springs to mind is how WSGI applications 
>> discover the file-system path name that corresponds to an URI.

[Phillip J. Eby]
> *boggle*  Why do you think that URIs have anything to do with file 
> paths?  In the general case, they are entirely unrelated.

Well, perhaps it's just that pretty much every web 
server/harness/framework I ever used has support for mapping URIs to 
files. How silly of me to try to apply my experience of other web 
systems to WSGI.

In the *general* case, yes, such a mapping has no meaning.

But there are specific cases, e.g. static file serving, where it is 
required.

[Phillip J. Eby]
> Well-written Python applications make this sort of thing part of their 
> configuration today already, because in the general case (e.g. 
> mod_rewrite) this stuff just plain isn't guessable.

It doesn't even have to be guessable: it could be standardised.

[Phillip J. Eby]
> Also, if you need access to local resources, relative to some Python 
> module, just grab the '__file__' attribute/variable of that module, and 
> then use 'os.path' functions to portably manipulate it.  E.g.:
> 
>     my_dir = os.path.dirname(__file__)
>     target = os.path.join(os.path.join(my_dir,"images"),"stars.jpg")
> 
> This is simple and portable.  If you need something more complex, you 
> should probably have configuration specific to the application that 
> spells out what it needs to know.

And that is a nice (python-specific) solution to the problem.

Perhaps it's worth adding something to the Q&A about how to map URIs to 
files in the local file system, based on the above pythonic, i.e. 
module.__file__, approach?

Alan.