Re: [libmicrohttpd] File imperative for MHD_post_process() and MHD_PostDataIterator()?

[Bob Furber]

Hi Christian,

I believe I have a solution: I have been using MHD_post_process() just 
because it "was there",  being used already for file uploads. What I 
failed to ask myself was: is there another way of processing some 
special Xml-Http-Request (xhr) Ajax POST requests?

The problem I ran into was that I provided a MHD_PostDataIterator 
function, iterate_xhrf(), which, in the 1st pass through 
[MHD_AccessHandlerCallback] answer_connection(), is linked to MHD as the 
post processor:

con_info->postprocessor = MHD_create_post_processor( connection, 
POSTBUFFERSIZE, iterate_xhrf, (void*)con_info );

Then, elsewhere, answer_connection() calls 
MHD_post_process(con_info->postprocessor, upload_data, *upload_data_size);

..to process the incoming POSTs

..but, con_info->postprocessor, the link to iterate_xhrf(), passed as a 
parameter to MHD_post_process(), DOES NOT call iterate_xhrf() when the 
data destined for a file is sent embedded in an xhr request.

However, when a file is uploaded, instead of data embedded in a xhr 
request, MHD_post_process() DOES call iterate_xhrf(). I believe the key 
difference is the xhr request lacks some of the header information 
enjoyed by a file upload; information such as [destination] filename and 
content_type.

However, there is nothing stopping me from calling my own custom post 
processor directly from answer_connection().

Bob


On 15-09-16 12:15 AM, Christian Grothoff wrote:
> Hi Bob,
>
> I do not understand your question at all. MHD_PostDataIterator is the
> type of a function you need to provide to the MHD PP, not something you
> 'access'.
>
> Also, I don't know what you are talking about with 'xdr data', maybe
> you're talking about some Microsoft non-standard XDomainRequest
> protocol, or something else non-standard?  Anyway, the MHD PP supports
> certain common HTTP POST encodings. If you require something
> else/different, you need to write your own POST-processor. The MHD API
> allows this, so there should be no problem for you if you can write your
> own parser.
>
> Happy hacking!
>
> Christian
>
> On 09/15/2015 08:18 PM, Bob Furber wrote:
> > Is there any way I can access a MHD_PostDataIterator when it is called
> > in a special situation where xhr data (not a file upload) is to be saved
> > to a file, instead of being a file upload? That is, data is uploaded
> > inside a xhr POST message, along with its destination path/filename.
> >
> > It seems that MHD_PostDataIterator parameters such as filename must
> > pre-exist in order for the MHD_PostDataIterator to be called. Is there
> > any way around this?