| // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| library multipart_request; |
| |
| import 'dart:async'; |
| import 'dart:math'; |
| import 'dart:utf'; |
| |
| import 'base_request.dart'; |
| import 'byte_stream.dart'; |
| import 'multipart_file.dart'; |
| import 'utils.dart'; |
| |
| /// A `multipart/form-data` request. Such a request has both string [fields], |
| /// which function as normal form fields, and (potentially streamed) binary |
| /// [files]. |
| /// |
| /// This request automatically sets the Content-Type header to |
| /// `multipart/form-data` and the Content-Transfer-Encoding header to `binary`. |
| /// These values will override any values set by the user. |
| /// |
| /// var uri = Uri.parse("http://pub.dartlang.org/packages/create"); |
| /// var request = new http.MultipartRequest("POST", url); |
| /// request.fields['user'] = 'nweiz@google.com'; |
| /// request.files.add(new http.MultipartFile.fromFile( |
| /// 'package', |
| /// new File('build/package.tar.gz'), |
| /// contentType: new ContentType('application', 'x-tar')); |
| /// request.send().then((response) { |
| /// if (response.statusCode == 200) print("Uploaded!"); |
| /// }); |
| class MultipartRequest extends BaseRequest { |
| /// The total length of the multipart boundaries used when building the |
| /// request body. According to http://tools.ietf.org/html/rfc1341.html, this |
| /// can't be longer than 70. |
| static const int _BOUNDARY_LENGTH = 70; |
| |
| static final Random _random = new Random(); |
| |
| /// The form fields to send for this request. |
| final Map<String, String> fields; |
| |
| /// The private version of [files]. |
| final List<MultipartFile> _files; |
| |
| /// Creates a new [MultipartRequest]. |
| MultipartRequest(String method, Uri url) |
| : super(method, url), |
| fields = {}, |
| _files = <MultipartFile>[]; |
| |
| /// The list of files to upload for this request. |
| List<MultipartFile> get files => _files; |
| |
| /// The total length of the request body, in bytes. This is calculated from |
| /// [fields] and [files] and cannot be set manually. |
| int get contentLength { |
| var length = 0; |
| |
| fields.forEach((name, value) { |
| length += "--".length + _BOUNDARY_LENGTH + "\r\n".length + |
| _headerForField(name, value).length + |
| encodeUtf8(value).length + "\r\n".length; |
| }); |
| |
| for (var file in _files) { |
| length += "--".length + _BOUNDARY_LENGTH + "\r\n".length + |
| _headerForFile(file).length + |
| file.length + "\r\n".length; |
| } |
| |
| return length + "--".length + _BOUNDARY_LENGTH + "--\r\n".length; |
| } |
| |
| void set contentLength(int value) { |
| throw new UnsupportedError("Cannot set the contentLength property of " |
| "multipart requests."); |
| } |
| |
| /// Freezes all mutable fields and returns a single-subscription [ByteStream] |
| /// that will emit the request body. |
| ByteStream finalize() { |
| // TODO(nweiz): freeze fields and files |
| var boundary = _boundaryString(); |
| headers['content-type'] = 'multipart/form-data; boundary="$boundary"'; |
| headers['content-transfer-encoding'] = 'binary'; |
| super.finalize(); |
| |
| var controller = new StreamController<List<int>>(sync: true); |
| |
| void writeAscii(String string) { |
| assert(isPlainAscii(string)); |
| controller.add(string.codeUnits); |
| } |
| |
| writeUtf8(String string) => controller.add(encodeUtf8(string)); |
| writeLine() => controller.add([13, 10]); // \r\n |
| |
| fields.forEach((name, value) { |
| writeAscii('--$boundary\r\n'); |
| writeAscii(_headerForField(name, value)); |
| writeUtf8(value); |
| writeLine(); |
| }); |
| |
| Future.forEach(_files, (file) { |
| writeAscii('--$boundary\r\n'); |
| writeAscii(_headerForFile(file)); |
| return writeStreamToSink(file.finalize(), controller) |
| .then((_) => writeLine()); |
| }).then((_) { |
| // TODO(nweiz): pass any errors propagated through this future on to |
| // the stream. See issue 3657. |
| writeAscii('--$boundary--\r\n'); |
| controller.close(); |
| }); |
| |
| return new ByteStream(controller.stream); |
| } |
| |
| /// All character codes that are valid in multipart boundaries. From |
| /// http://tools.ietf.org/html/rfc2046#section-5.1.1. |
| static const List<int> _BOUNDARY_CHARACTERS = const <int>[ |
| 39, 40, 41, 43, 95, 44, 45, 46, 47, 58, 61, 63, 48, 49, 50, 51, 52, 53, 54, |
| 55, 56, 57, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, |
| 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 97, 98, 99, 100, 101, 102, 103, |
| 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, |
| 119, 120, 121, 122 |
| ]; |
| |
| /// Returns the header string for a field. The return value is guaranteed to |
| /// contain only ASCII characters. |
| String _headerForField(String name, String value) { |
| // http://tools.ietf.org/html/rfc2388 mandates some complex encodings for |
| // field names and file names, but in practice user agents seem to just |
| // URL-encode them so we do the same. |
| var header = |
| 'content-disposition: form-data; name="${Uri.encodeFull(name)}"'; |
| if (!isPlainAscii(value)) { |
| header = '$header\r\ncontent-type: text/plain; charset=utf-8'; |
| } |
| return '$header\r\n\r\n'; |
| } |
| |
| /// Returns the header string for a file. The return value is guaranteed to |
| /// contain only ASCII characters. |
| String _headerForFile(MultipartFile file) { |
| var header = 'content-type: ${file.contentType}\r\n' |
| 'content-disposition: form-data; name="${Uri.encodeFull(file.field)}"'; |
| |
| if (file.filename != null) { |
| header = '$header; filename="${Uri.encodeFull(file.filename)}"'; |
| } |
| return '$header\r\n\r\n'; |
| } |
| |
| /// Returns a randomly-generated multipart boundary string |
| String _boundaryString() { |
| var prefix = "dart-http-boundary-"; |
| var list = new List<int>.generate(_BOUNDARY_LENGTH - prefix.length, |
| (index) => |
| _BOUNDARY_CHARACTERS[_random.nextInt(_BOUNDARY_CHARACTERS.length)], |
| growable: false); |
| return "$prefix${new String.fromCharCodes(list)}"; |
| } |
| } |