Dart

HTTP multipart/form-data Upload

See more HTTP Examples

Demonstrates how to upload files to an HTTP server using a multipart/form-data POST. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  final http = CkHttp();

  final req = CkHttpRequest();
  req.httpVerb = 'POST';
  req.contentType = 'multipart/form-data';
  req.path = 'rcvFormDataUpload.aspx';

  // Send an "Expect: 100-continue" header in the request.
  // This causes the HTTP server to end a 100-continue response
  // immediately after receiving the HTTP header.  The client
  // (Chilkat) will receive this intermediate response, and if
  // it's not an error response, it knows that the HTTP server will
  // accept the data that is forthcoming.
  // The alternative is to get an error response after trying to upload
  // the entire contents of the files.
  req.addHeader('Expect', '100-continue');

  // Call AddFileForUpload2 for each file to be uploaded in the HTTP multipart/form-data POST
  // To allow Chilkat to determine the content-type automatically based on file-extension,
  // call AddFileForUpload instead.

  // The 1st arg is the filename passed in the HTTP request.
  // The 2nd arg is the path in the local filesytem.
  // The file is not loaded into memory.  It is streamed directly from the file
  // when the HTTP POST is sent.
  try {
    req.addFileForUpload2('starfish.jpg', 'c:/qa_data/starfish.jpg', 'image/jpg');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    req.addFileForUpload('something.pdf', 'c:/qa_data/something.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Its also possible to add a file from a string:
  req.addStringForUpload('test.xml', 'test.xml', '<abc>This is the test.xml content</abc>', 'utf-8');
  // We'll assume success since no files are involved..

  // This sends the HTTP request (with 3 files being uploaded) to
  // http://www.mywebserver123abc.com/rcvFormDataUpload.aspx
  final resp = CkHttpResponse();
  try {
    http.httpSReq('www.mywebserver123abc.com', 80, false, req, resp);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('HTTP response status: ${resp.statusCode}');
  // See the online reference documentation for 
  // other information that can be obtained from the response object.

  // To send using SSL/TLS, do this instead.
  // This sends to https://www.mywebserver123abc.com/rcvFormDataUpload.aspx
  try {
    http.httpSReq('www.mywebserver123abc.com', 443, true, req, resp);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('HTTP response status: ${resp.statusCode}');
  // See the online reference documentation for 
  // other information that can be obtained from the response object.
}