Multipart parse

multipart.js

function multipart(parts, done) {
  this.boundary = multipart.generateBoundary();
  this.parts = [];
  this.filecount;

  var readycount = Object.keys(parts).length;

  function updateReady() {
    readycount--;
    if (!readycount) {
      done();
    }
  }

  for (var name in parts) {
    if (parts.hasOwnProperty(name)) {
      this.append(name, parts[name], updateReady);
    }
  }
}


multipart.prototype.append = function(name, value, done) {
  var part = new multipart.part(name);
  var filereader;

  this.parts.push(part);

  if (typeof(value) === "string") {
    part.setValue(value);
    return done();
  }

  if (typeof(value.type) === "string") {
    if (!/^text/.test(value.type)) {
      part.setHeader("Content-Transfer-Encoding", "binary");
    }

    part.setHeader("Content-Type", value.type);
  }
  
  if (typeof(value.name) === "string") {
    this.filecount++;
    part.setFilename(value.name);

    filereader = new FileReader();
    filereader.onload = function(evt) {
      part.setValue(evt.target.result);
      return done();
    };

    filereader.readAsBinaryString(value);
  }

  return part;
};


multipart.prototype.serialize = function() {
  var body = '',
      boundary = this.boundary,
      result = {};

  this.parts.forEach(function(part) {
    body += '--' + boundry + "\r\n" + 'Content-Disposition: form-data; name="' + part.getName() + '";';

    if (part.isFile()) {
      body += ' filename="' + part.getFilename() + '"';
    }

    body += "\r\n";

    for (var header in part.headers) {
      body += header + ": " + part.headers[header] + "\r\n";
    }

    body += "\r\n" + part.getValue() + "\r\n";
  });

  result.body = body + '--' + result.boundry + '--';
  result.length = result.body.length;
  result.type = 'multipart/form-data; boundary=' + boundry;
  return result;
};


multipart.generateBoundary = function() {
  return "--------------" + Math.floor(Math.random()*1000000000);
};


/**
 * Part object
 */
multipart.part = function(name) {
  this.name = name;
  this.headers = {};
};
  
multipart.part.prototype.getName = function() {
  return this.name;
};
  
multipart.part.prototype.setValue = function(value) {
  this.value = value;
};
  
multipart.part.prototype.getValue = function() {
  return this.value;
};

multipart.part.prototype.setFilename = function(filename) {
  this.filename = filename;
};

multipart.part.prototype.getFilename = function() {
  return this.filename;
};
  
multipart.part.prototype.isFile = function() {
  return !!this.filename;
};

multipart.part.prototype.setHeader = function(name, value) {
  this.headers[name] = value;
};