#!/usr/bin/env python
     # encoding: utf-8
     #
     # Copyright (c) 2008 Doug Hellmann All rights reserved.
     #
     """
     """
     #end_pymotw_header
     
     import itertools
     import mimetools
     import mimetypes
     from cStringIO import StringIO
     import urllib
     import urllib2
     
     class MultiPartForm(object):
         """Accumulate the data to be used when posting a form."""
     
         def __init__(self):
             self.form_fields = []
             self.files = []
             self.boundary = mimetools.choose_boundary()
             return
         
         def get_content_type(self):
             return 'multipart/form-data; boundary=%s' % self.boundary
     
         def add_field(self, name, value):
             """Add a simple field to the form data."""
             self.form_fields.append((name, value))
             return
     
         def add_file(self, fieldname, filename, fileHandle, mimetype=None):
             """Add a file to be uploaded."""
             body = fileHandle.read()
             if mimetype is None:
                 mimetype = mimetypes.guess_type(filename)[0] or 'application/octet-stream'
             self.files.append((fieldname, filename, mimetype, body))
             return
         
         def __str__(self):
             """Return a string representing the form data, including attached files."""
             # Build a list of lists, each containing "lines" of the
             # request.  Each part is separated by a boundary string.
             # Once the list is built, return a string where each
             # line is separated by '\r\n'.  
             parts = []
             part_boundary = '--' + self.boundary
             
             # Add the form fields
             parts.extend(
                 [ part_boundary,
                   'Content-Disposition: form-data; name="%s"' % name,
                   '',
                   value,
                 ]
                 for name, value in self.form_fields
                 )
             
             # Add the files to upload
             parts.extend(
                 [ part_boundary,
                   'Content-Disposition: file; name="%s"; filename="%s"' % \
                      (field_name, filename),
                   'Content-Type: %s' % content_type,
                   '',
                   body,
                 ]
                 for field_name, filename, content_type, body in self.files
                 )
             
             # Flatten the list and add closing boundary marker,
             # then return CR+LF separated data
             flattened = list(itertools.chain(*parts))
             flattened.append('--' + self.boundary + '--')
             flattened.append('')
             return '\r\n'.join(flattened)
     
     if __name__ == '__main__':
         # Create the form with simple fields
         form = MultiPartForm()
         form.add_field('firstname', 'Doug')
         form.add_field('lastname', 'Hellmann')
         
         # Add a fake file
         form.add_file('biography', 'bio.txt', 
                       fileHandle=StringIO('Python developer and blogger.'))
     
         # Build the request
         request = urllib2.Request('http://localhost:8080/')
         request.add_header('User-agent', 'PyMOTW (http://www.doughellmann.com/PyMOTW/)')
         body = str(form)
         request.add_header('Content-type', form.get_content_type())
         request.add_header('Content-length', len(body))
         request.add_data(body)
     
         print
         print 'OUTGOING DATA:'
         print request.get_data()
     
         print
         print 'SERVER RESPONSE:'
         print urllib2.urlopen(request).read()