[mod_python] Mod-Python Help

Ethan Toan Ton wrote:
> Graham/David,
> 
> Thanks for the help. My packet sniffer is looking at the packets, and instead
> of a new packet header, all these req.flush() calls are keeping the
> connection
> alive. Unfortunately, the javascript xmlhttprequest will only process the
> packet once, instead of during every call to req.flush().
> 
> Is there a way to close the connection and open it again afterwards? I'm
> trying to get the xmlhttprequest.onreadystatechange to process after each
> call
> to req.flush().

Of course req.flush() does not close the connection. It just causes 
apache to send the current contents of the response buffer. Apache will 
close the connection only when the request processing has completed. 
This is the way http works.

Jim

> Ethan
> 
> 
>> On 07/09/2006, at 10:39 AM, David Beal wrote:
>>
>>> Ethan,
>>>
>>>> Thanks for your help.  It turns out the problem was the "return
>>>> apache.OK".  I was getting that extra 0 at the end and could not
>>>> figure
>>>> out why.  Thanks for the prompt replies.  I appreciate all the help.
>>>>
>>> The problem is probably not with return apache.OK, but maybe with the
>>> client's XmlHttpRequest handler not understanding chunked encoding
>>> markers.  The 0 is for HTTP chunked encoding.  Look for the header:
>>>
>>> Transfer-Encoding: chunked
>>>
>>> and the first line of the content will be a hexadecimal number of the
>>> content-length for the first chunk.  Each subsequent chunk comes
>>> with a
>>> chunk length marker.  The 0 at the end of the file indicates that
>>> there
>>> are no more chunks.  Chunk length markers will also appear whenever an
>>> output flush occurs.
>>>
>>> To disable chunked encoding, you should specify a content length:
>>>
>>> req.headers_out['Content-Length']=str(len(code))
>> I'd suggest it isn't anything to do with chunked encoding and the
>> original
>> suggestion about apache.OK is going to be correct.
>>
>> It is an occasional problem we have to correct whereby people who move
>> from a mod_python basic handler to mod_python.publisher keep returning
>> apache.OK as a status when they shouldn't with result of an extra '0'
>> appearing in response.
>>
>> Ie., a mod_python basic handler of:
>>
>>    def handler(req):
>>      req.content_type = 'text/plain'
>>      req.write("content")
>>      return apache.OK
>>
>> can not simply be taken and then used as mod_python.publisher
>> function as:
>>
>>    def index(req):
>>      req.content_type = 'text/plain'
>>      req.write("content")
>>      return apache.OK
>>
>> This is because mod_python.publisher will always take the result of
>> the function
>> and convert it to a string and append it to the response, even if
>> req.write() were
>> used. Thus, must be written as:
>>
>>    def index(req):
>>      req.content_type = 'text/plain'
>>      req.write("content")
>>
>> or for older versions of mod_python where returning None or an empty
>> string is
>> a problem, written as:
>>
>>    def index(req):
>>      req.content_type = 'text/plain'
>>      req.write("content")
>>      return ' '
>>
>> Graham
>>
> 
> 
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