[Twisted-web] requestHeaders issues

[Phil Christensen]

Hi all,

I've run into a problem in Twisted.Web with a recent addition to SVN  
head. The problem occurs in my WSGI gateway module, which is derived  
from web2's version. When I'm creating the environment dictionary by  
iterating like this:

     # Propagate HTTP headers
     for title in request.received_headers:
         header = request.received_headers[title]
         ...
         ...

the iteration through received_headers causes the following exception:

     Traceback (most recent call last):
       File "/Users/phil/Workspace/modu/modu/web/wsgi.py", line 91, in  
createCGIEnvironment
         for title in request.received_headers:
       File "/Users/phil/Workspace/Twisted/twisted/web/ 
http_headers.py", line 41, in __getitem__
         if self._headers.hasHeader(key):
       File "/Users/phil/Workspace/Twisted/twisted/web/ 
http_headers.py", line 247, in hasHeader
         return name.lower() in self._rawHeaders
     exceptions.AttributeError: 'int' object has no attribute 'lower'

After some searching, I found this patch:

     r23826 | exarkun | 2008-06-02 11:06:06 -0400 (Mon, 02 Jun 2008) |  
15 lines

     Merge web-headers-165-2

     Author: dreid, exarkun
     Reviewer: therve
     Fixes: #165

     Add two new attributes to twisted.web.http.Request,  
`requestHeaders` and
     `responseHeaders`, which parallel the previous attributes  
`received_headers`
     and `headers`.  The new attributes are preferred and provide a  
structured
     interface to accessing and manipulating header information,  
including
     multiples values per header which was unsupported by the previous  
API.
     `received_headers` and `headers` are not deprecated and coding  
using
     them will continue to work, but their use is discouraged and they  
will be
     deprecated at some future time.

If I make those changes and use `requestHeaders` instead, like this:

     # Propagate HTTP headers
     for title in request.received_headers:
         header = request.received_headers[title]
         ...
         ...

I instead get the following traceback:

     Traceback (most recent call last):
       File "/Users/phil/Workspace/modu/modu/web/wsgi.py", line 91, in  
createCGIEnvironment
         for title in request.requestHeaders:
     exceptions.TypeError: 'Headers' object is not iterable

which seems strange to me, since from what I can tell,  
request.requestHeaders should be a http_headers._DictHeaders instance.  
Should I be calling request.requestHeaders.getAllRawHeaders() and  
iterate through that result instead?

Any guidance in this matter would be greatly appreciated.

Thanks again,

-phil