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1var CombinedStream = require('combined-stream');
2var util = require('util');
3var path = require('path');
4var http = require('http');
5var https = require('https');
6var parseUrl = require('url').parse;
7var fs = require('fs');
8var mime = require('mime-types');
9var asynckit = require('asynckit');
10var populate = require('./populate.js');
11
12// Public API
13module.exports = FormData;
14
15// make it a Stream
16util.inherits(FormData, CombinedStream);
17
18/**
19 * Create readable "multipart/form-data" streams.
20 * Can be used to submit forms
21 * and file uploads to other web applications.
22 *
23 * @constructor
24 * @param {Object} options - Properties to be added/overriden for FormData and CombinedStream
25 */
26function FormData(options) {
27  if (!(this instanceof FormData)) {
28    return new FormData();
29  }
30
31  this._overheadLength = 0;
32  this._valueLength = 0;
33  this._valuesToMeasure = [];
34
35  CombinedStream.call(this);
36
37  options = options || {};
38  for (var option in options) {
39    this[option] = options[option];
40  }
41}
42
43FormData.LINE_BREAK = '\r\n';
44FormData.DEFAULT_CONTENT_TYPE = 'application/octet-stream';
45
46FormData.prototype.append = function(field, value, options) {
47
48  options = options || {};
49
50  // allow filename as single option
51  if (typeof options == 'string') {
52    options = {filename: options};
53  }
54
55  var append = CombinedStream.prototype.append.bind(this);
56
57  // all that streamy business can't handle numbers
58  if (typeof value == 'number') {
59    value = '' + value;
60  }
61
62  // https://github.com/felixge/node-form-data/issues/38
63  if (util.isArray(value)) {
64    // Please convert your array into string
65    // the way web server expects it
66    this._error(new Error('Arrays are not supported.'));
67    return;
68  }
69
70  var header = this._multiPartHeader(field, value, options);
71  var footer = this._multiPartFooter();
72
73  append(header);
74  append(value);
75  append(footer);
76
77  // pass along options.knownLength
78  this._trackLength(header, value, options);
79};
80
81FormData.prototype._trackLength = function(header, value, options) {
82  var valueLength = 0;
83
84  // used w/ getLengthSync(), when length is known.
85  // e.g. for streaming directly from a remote server,
86  // w/ a known file a size, and not wanting to wait for
87  // incoming file to finish to get its size.
88  if (options.knownLength != null) {
89    valueLength += +options.knownLength;
90  } else if (Buffer.isBuffer(value)) {
91    valueLength = value.length;
92  } else if (typeof value === 'string') {
93    valueLength = Buffer.byteLength(value);
94  }
95
96  this._valueLength += valueLength;
97
98  // @check why add CRLF? does this account for custom/multiple CRLFs?
99  this._overheadLength +=
100    Buffer.byteLength(header) +
101    FormData.LINE_BREAK.length;
102
103  // empty or either doesn't have path or not an http response
104  if (!value || ( !value.path && !(value.readable && value.hasOwnProperty('httpVersion')) )) {
105    return;
106  }
107
108  // no need to bother with the length
109  if (!options.knownLength) {
110    this._valuesToMeasure.push(value);
111  }
112};
113
114FormData.prototype._lengthRetriever = function(value, callback) {
115
116  if (value.hasOwnProperty('fd')) {
117
118    // take read range into a account
119    // `end` = Infinity –> read file till the end
120    //
121    // TODO: Looks like there is bug in Node fs.createReadStream
122    // it doesn't respect `end` options without `start` options
123    // Fix it when node fixes it.
124    // https://github.com/joyent/node/issues/7819
125    if (value.end != undefined && value.end != Infinity && value.start != undefined) {
126
127      // when end specified
128      // no need to calculate range
129      // inclusive, starts with 0
130      callback(null, value.end + 1 - (value.start ? value.start : 0));
131
132    // not that fast snoopy
133    } else {
134      // still need to fetch file size from fs
135      fs.stat(value.path, function(err, stat) {
136
137        var fileSize;
138
139        if (err) {
140          callback(err);
141          return;
142        }
143
144        // update final size based on the range options
145        fileSize = stat.size - (value.start ? value.start : 0);
146        callback(null, fileSize);
147      });
148    }
149
150  // or http response
151  } else if (value.hasOwnProperty('httpVersion')) {
152    callback(null, +value.headers['content-length']);
153
154  // or request stream http://github.com/mikeal/request
155  } else if (value.hasOwnProperty('httpModule')) {
156    // wait till response come back
157    value.on('response', function(response) {
158      value.pause();
159      callback(null, +response.headers['content-length']);
160    });
161    value.resume();
162
163  // something else
164  } else {
165    callback('Unknown stream');
166  }
167};
168
169FormData.prototype._multiPartHeader = function(field, value, options) {
170  // custom header specified (as string)?
171  // it becomes responsible for boundary
172  // (e.g. to handle extra CRLFs on .NET servers)
173  if (typeof options.header == 'string') {
174    return options.header;
175  }
176
177  var contentDisposition = this._getContentDisposition(value, options);
178  var contentType = this._getContentType(value, options);
179
180  var contents = '';
181  var headers  = {
182    // add custom disposition as third element or keep it two elements if not
183    'Content-Disposition': ['form-data', 'name="' + field + '"'].concat(contentDisposition || []),
184    // if no content type. allow it to be empty array
185    'Content-Type': [].concat(contentType || [])
186  };
187
188  // allow custom headers.
189  if (typeof options.header == 'object') {
190    populate(headers, options.header);
191  }
192
193  var header;
194  for (var prop in headers) {
195    if (!headers.hasOwnProperty(prop)) continue;
196    header = headers[prop];
197
198    // skip nullish headers.
199    if (header == null) {
200      continue;
201    }
202
203    // convert all headers to arrays.
204    if (!Array.isArray(header)) {
205      header = [header];
206    }
207
208    // add non-empty headers.
209    if (header.length) {
210      contents += prop + ': ' + header.join('; ') + FormData.LINE_BREAK;
211    }
212  }
213
214  return '--' + this.getBoundary() + FormData.LINE_BREAK + contents + FormData.LINE_BREAK;
215};
216
217FormData.prototype._getContentDisposition = function(value, options) {
218
219  var filename
220    , contentDisposition
221    ;
222
223  if (typeof options.filepath === 'string') {
224    // custom filepath for relative paths
225    filename = path.normalize(options.filepath).replace(/\\/g, '/');
226  } else if (options.filename || value.name || value.path) {
227    // custom filename take precedence
228    // formidable and the browser add a name property
229    // fs- and request- streams have path property
230    filename = path.basename(options.filename || value.name || value.path);
231  } else if (value.readable && value.hasOwnProperty('httpVersion')) {
232    // or try http response
233    filename = path.basename(value.client._httpMessage.path);
234  }
235
236  if (filename) {
237    contentDisposition = 'filename="' + filename + '"';
238  }
239
240  return contentDisposition;
241};
242
243FormData.prototype._getContentType = function(value, options) {
244
245  // use custom content-type above all
246  var contentType = options.contentType;
247
248  // or try `name` from formidable, browser
249  if (!contentType && value.name) {
250    contentType = mime.lookup(value.name);
251  }
252
253  // or try `path` from fs-, request- streams
254  if (!contentType && value.path) {
255    contentType = mime.lookup(value.path);
256  }
257
258  // or if it's http-reponse
259  if (!contentType && value.readable && value.hasOwnProperty('httpVersion')) {
260    contentType = value.headers['content-type'];
261  }
262
263  // or guess it from the filepath or filename
264  if (!contentType && (options.filepath || options.filename)) {
265    contentType = mime.lookup(options.filepath || options.filename);
266  }
267
268  // fallback to the default content type if `value` is not simple value
269  if (!contentType && typeof value == 'object') {
270    contentType = FormData.DEFAULT_CONTENT_TYPE;
271  }
272
273  return contentType;
274};
275
276FormData.prototype._multiPartFooter = function() {
277  return function(next) {
278    var footer = FormData.LINE_BREAK;
279
280    var lastPart = (this._streams.length === 0);
281    if (lastPart) {
282      footer += this._lastBoundary();
283    }
284
285    next(footer);
286  }.bind(this);
287};
288
289FormData.prototype._lastBoundary = function() {
290  return '--' + this.getBoundary() + '--' + FormData.LINE_BREAK;
291};
292
293FormData.prototype.getHeaders = function(userHeaders) {
294  var header;
295  var formHeaders = {
296    'content-type': 'multipart/form-data; boundary=' + this.getBoundary()
297  };
298
299  for (header in userHeaders) {
300    if (userHeaders.hasOwnProperty(header)) {
301      formHeaders[header.toLowerCase()] = userHeaders[header];
302    }
303  }
304
305  return formHeaders;
306};
307
308FormData.prototype.getBoundary = function() {
309  if (!this._boundary) {
310    this._generateBoundary();
311  }
312
313  return this._boundary;
314};
315
316FormData.prototype._generateBoundary = function() {
317  // This generates a 50 character boundary similar to those used by Firefox.
318  // They are optimized for boyer-moore parsing.
319  var boundary = '--------------------------';
320  for (var i = 0; i < 24; i++) {
321    boundary += Math.floor(Math.random() * 10).toString(16);
322  }
323
324  this._boundary = boundary;
325};
326
327// Note: getLengthSync DOESN'T calculate streams length
328// As workaround one can calculate file size manually
329// and add it as knownLength option
330FormData.prototype.getLengthSync = function() {
331  var knownLength = this._overheadLength + this._valueLength;
332
333  // Don't get confused, there are 3 "internal" streams for each keyval pair
334  // so it basically checks if there is any value added to the form
335  if (this._streams.length) {
336    knownLength += this._lastBoundary().length;
337  }
338
339  // https://github.com/form-data/form-data/issues/40
340  if (!this.hasKnownLength()) {
341    // Some async length retrievers are present
342    // therefore synchronous length calculation is false.
343    // Please use getLength(callback) to get proper length
344    this._error(new Error('Cannot calculate proper length in synchronous way.'));
345  }
346
347  return knownLength;
348};
349
350// Public API to check if length of added values is known
351// https://github.com/form-data/form-data/issues/196
352// https://github.com/form-data/form-data/issues/262
353FormData.prototype.hasKnownLength = function() {
354  var hasKnownLength = true;
355
356  if (this._valuesToMeasure.length) {
357    hasKnownLength = false;
358  }
359
360  return hasKnownLength;
361};
362
363FormData.prototype.getLength = function(cb) {
364  var knownLength = this._overheadLength + this._valueLength;
365
366  if (this._streams.length) {
367    knownLength += this._lastBoundary().length;
368  }
369
370  if (!this._valuesToMeasure.length) {
371    process.nextTick(cb.bind(this, null, knownLength));
372    return;
373  }
374
375  asynckit.parallel(this._valuesToMeasure, this._lengthRetriever, function(err, values) {
376    if (err) {
377      cb(err);
378      return;
379    }
380
381    values.forEach(function(length) {
382      knownLength += length;
383    });
384
385    cb(null, knownLength);
386  });
387};
388
389FormData.prototype.submit = function(params, cb) {
390  var request
391    , options
392    , defaults = {method: 'post'}
393    ;
394
395  // parse provided url if it's string
396  // or treat it as options object
397  if (typeof params == 'string') {
398
399    params = parseUrl(params);
400    options = populate({
401      port: params.port,
402      path: params.pathname,
403      host: params.hostname,
404      protocol: params.protocol
405    }, defaults);
406
407  // use custom params
408  } else {
409
410    options = populate(params, defaults);
411    // if no port provided use default one
412    if (!options.port) {
413      options.port = options.protocol == 'https:' ? 443 : 80;
414    }
415  }
416
417  // put that good code in getHeaders to some use
418  options.headers = this.getHeaders(params.headers);
419
420  // https if specified, fallback to http in any other case
421  if (options.protocol == 'https:') {
422    request = https.request(options);
423  } else {
424    request = http.request(options);
425  }
426
427  // get content length and fire away
428  this.getLength(function(err, length) {
429    if (err) {
430      this._error(err);
431      return;
432    }
433
434    // add content length
435    request.setHeader('Content-Length', length);
436
437    this.pipe(request);
438    if (cb) {
439      request.on('error', cb);
440      request.on('response', cb.bind(this, null));
441    }
442  }.bind(this));
443
444  return request;
445};
446
447FormData.prototype._error = function(err) {
448  if (!this.error) {
449    this.error = err;
450    this.pause();
451    this.emit('error', err);
452  }
453};
454
455FormData.prototype.toString = function () {
456  return '[object FormData]';
457};
458