Changes to support custom content-type and getLengthSync.

lib/form_data.js

@@ -96,7 +96,7 @@ FormData.prototype._lastBoundary = function() {
 
 FormData.prototype.getHeaders = function(userHeaders) {
   var formHeaders = {
-    'content-type': 'multipart/form-data; boundary=' + this.getBoundary(),
+    'content-type': 'multipart/form-data; boundary=' + this.getBoundary()
   };
 
   for (var header in userHeaders) {
@@ -106,6 +106,17 @@ FormData.prototype.getHeaders = function(userHeaders) {
   return formHeaders;
 }
 
+FormData.prototype.getCustomHeaders = function(contentType) {
+    contentType = contentType ? contentType : 'multipart/form-data';
+
+    var formHeaders = {
+        'content-type': contentType + '; boundary=' + this.getBoundary(),
+        'content-length': this.getLengthSync()
+    };
+
+    return formHeaders;
+}
+
 FormData.prototype.getBoundary = function() {
   if (!this._boundary) {
     this._generateBoundary();
@@ -125,6 +136,16 @@ FormData.prototype._generateBoundary = function() {
   this._boundary = boundary;
 };
 
+FormData.prototype.getLengthSync = function() {
+    var knownLength = this._overheadLength + this._valueLength;
+
+    if (this._streams.length) {
+        knownLength += this._lastBoundary().length;
+    }
+
+    return knownLength;
+};
+
 FormData.prototype.getLength = function(cb) {
   var knownLength = this._overheadLength + this._valueLength;