MultipartPostHandler.py

#!/usr/bin/python

####
# 06/2010 Nic Wolfe <nic@wolfeden.ca>
# 02/2006 Will Holcomb <wholcomb@gmail.com>
# 
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
# 
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#

import urllib
import urllib2
import mimetools, mimetypes
import os, sys

# Controls how sequences are uncoded. If true, elements may be given multiple values by
#  assigning a sequence.
doseq = 1

class MultipartPostHandler(urllib2.BaseHandler):
    handler_order = urllib2.HTTPHandler.handler_order - 10 # needs to run first

    def http_request(self, request):
        data = request.get_data()
        if data is not None and type(data) != str:
            v_files = []
            v_vars = []
            try:
                for(key, value) in data.items():
                    if type(value) in (file, list, tuple):
                        v_files.append((key, value))
                    else:
                        v_vars.append((key, value))
            except TypeError:
                systype, value, traceback = sys.exc_info()
                raise TypeError, "not a valid non-string sequence or mapping object", traceback

            if len(v_files) == 0:
                data = urllib.urlencode(v_vars, doseq)
            else:
                boundary, data = MultipartPostHandler.multipart_encode(v_vars, v_files)
                contenttype = 'multipart/form-data; boundary=%s' % boundary
                if(request.has_header('Content-Type')
                   and request.get_header('Content-Type').find('multipart/form-data') != 0):
                    print "Replacing %s with %s" % (request.get_header('content-type'), 'multipart/form-data')
                request.add_unredirected_header('Content-Type', contenttype)

            request.add_data(data)
        return request

    @staticmethod
    def multipart_encode(vars, files, boundary = None, buffer = None):
        if boundary is None:
            boundary = mimetools.choose_boundary()
        if buffer is None:
            buffer = ''
        for(key, value) in vars:
            buffer += '--%s\r\n' % boundary
            buffer += 'Content-Disposition: form-data; name="%s"' % key
            buffer += '\r\n\r\n' + value + '\r\n'
        for(key, fd) in files:
            
            # allow them to pass in a file or a tuple with name & data
            if type(fd) == file:
                name_in = fd.name
                fd.seek(0)
                data_in = fd.read()
            elif type(fd) in (tuple, list):
                name_in, data_in = fd
                
            filename = os.path.basename(name_in)
            contenttype = mimetypes.guess_type(filename)[0] or 'application/octet-stream'
            buffer += '--%s\r\n' % boundary
            buffer += 'Content-Disposition: form-data; name="%s"; filename="%s"\r\n' % (key, filename)
            buffer += 'Content-Type: %s\r\n' % contenttype
            # buffer += 'Content-Length: %s\r\n' % file_size
            buffer += '\r\n' + data_in + '\r\n'
        buffer += '--%s--\r\n\r\n' % boundary
        return boundary, buffer

    https_request = http_request