1 // Copyright 2009 Google Inc.  All Rights Reserved.

     2 

     3 /**

     4  * A multipart form data construction class for XHR.

     5  * @see http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html

     6  * @constructor

     7  */

     8 var MultipartFormData = function() {

     9   /**

    10    * @type {Array}

    11    */

    12   this.headers = [];

    13 

    14   /**

    15    * @type {Array}

    16    */

    17   this.parts = [];

    18 

    19   /**

    20    * A random string for the boundary.

    21    * @type {string}

    22    */

    23   this.boundary = MultipartFormData.getRandomBoundary();

    24 };

    25 

    26 

    27 /**

    28  * @type {string}

    29  */

    30 MultipartFormData.CRLF = '\r\n';

    31 

    32 

    33 /**

    34  * @type {string}

    35  * @private

    36  */

    37 MultipartFormData.TEN_CHARS_ =

    38 

    39 

    40 /**

    41  * Generates a random number and some random characters from it.

    42  */

    43 MultipartFormData.getRandomBoundary = function() {

    44   var anyTenCharacters = 'DiStRIcT10';

    45   var randomNumber = Math.floor(Math.random() * 10000000);

    46   var nums = randomNumber.toString().split('');

    47   var randomChars = '';

    48   for (var i = 0, num; num = nums[i]; i++) {

    49     randomChars += anyTenCharacters[num];

    50   }

    51   return randomChars + '-' + randomNumber;

    52 };

    53 

    54 

    55 /**

    56  * @param {string} name The name for this header.

    57  * @param {string} value The value for this header.

    58  */

    59 MultipartFormData.prototype.addHeader = function(name, value) {

    60   this.headers.push({

    61     'name': name,

    62     'value': value

    63   });

    64 };

    65 

    66 

    67 /**

    68  * @param {?string} name The name for this part.

    69  * @param {string} value The value for this part.

    70  * @param {string} opt_contentType Content-type for this part.

    71  * @param {string} opt_contentDisposition Content disposition for this part.

    72  * @param {string} opt_filename The filename for this part

    73  */

    74 MultipartFormData.prototype.addPart = function(name, value, opt_contentType,

    75     opt_contentDisposition, opt_filename) {

    76   var contentType = opt_contentType || null;

    77   var contentDisposition = opt_contentDisposition || null;

    78   var filename = opt_filename || null;

    79   this.parts.push({

    80     'name': name,

    81     'value': value,

    82     'contentType': contentType,

    83     'contentDisposition': contentDisposition,

    84     'filename': filename

    85   });

    86 };

    87 

    88 /**

    89  * @return {string} The string to set as a payload.

    90  */

    91 MultipartFormData.prototype.toString = function() {

    92   var lines = [];

    93 

    94   for (var i = 0, header; header = this.headers[i]; i++) {

    95     lines.push(header['name'] + ': ' + header['value']);

    96   }

    97   if (this.headers.length > 0) {

    98     lines.push('');

    99   }

   100 

   101   for (var i = 0, part; part = this.parts[i]; i++) {

   102     lines.push('--' + this.boundary);

   103 

   104     if (part['contentDisposition']) {

   105       var contentDisposition = 'Content-Disposition: form-data; ';

   106       contentDisposition += 'name="' + part['name'] + '"';

   107       if (part['filename']) {

   108         contentDisposition += '; filename="' + part['filename'] + '"';

   109       }

   110       lines.push(contentDisposition);

   111     }

   112 

   113     if (part['contentType']) {

   114       lines.push('Content-Type: ' + part['contentType']);

   115     }

   116 

   117     lines.push('');

   118     lines.push(part['value']);

   119   }

   120 

   121   lines.push('--' + this.boundary + '--');

   122 

   123   return lines.join(MultipartFormData.CRLF) + MultipartFormData.CRLF;

   124 };

   125