[Zope] Product that catches webdav PUTs and does something else

[Brian Lloyd]

> Thanks Brian, that does seem to be what I'm after, however, I 
> couldn't make
> it do what I expected.  After many attempts at solving the problem, I
> defined a PUT method that seems to be called instead of the 
> PUT_factory when
> uploading from Composer into the webdav_src_port.  Is this what would be
> expected?  If so, I think I misunderstand the use of PUT_factory.

Here is a quick primer on what happens when a PUT occurs. 
Lets say you do a PUT on /foo/bar/file.html, an object 
*that already exists* in the system. In this case:

  - the publisher traverses to the object /foo/bar/file.html
  - if the HTTP request method is GET or POST, it looks for 
    index_html. Otherwise (as in this case), it looks for 
    a method on the object matching the HTTP method (PUT).

So if /foo/bar/file.html already exists, it's PUT method will 
be called. This is the case for editing / updating existing 
objects.

Where the PUT_factory comes in is when /foo/bar/file.html does 
*not* yet exist. In this case:

  - the publisher traverses to /foo/bar/file.html. When it asks
    'bar' for 'file.html' ( assuming 'bar' is a Folder), 'bar' 
    finds that it doesn't exist so it returns a special object 
    called a 'NullResource'. NullResource is a class defined 
    in the lib/python/webdav package, and its sole purpose is 
    to have a PUT method that will be called in this case (where
    no object exists yet).

The PUT implementation of NullResource objects first tries to 
delegate to self.PUT_factory(...), which gives app developers an 
opportunity to expand on the default handling of a PUT on a 
non-existing resource. The NullResource is an acquirer, so the 
developer can implement a PUT_factory as a method of the container, 
or as a Python Script, whatever, to override the default behavior 
of the NullResource PUT. The default behavior (used if no PUT_factory
is found), is to try to 'do the right thing' based on the mime-type
or file extension (create a DTMLDocument for .txt, .html; Image for 
.gif, .jpg; File for anything else).

Hopefully this sheds some light on what happens underneath and 
make the PUT_factory document more useful - if you still can't 
get PUT_factory to work as expected you might want to contact 
the author (Tres) to make sure it is up to date (I can't tell 
from a glance - but knowing Tres I suspect it is up to date :).

Brian Lloyd        brian@digicool.com
Software Engineer  540.371.6909              
Digital Creations  http://www.digicool.com