JS- support clear() method on builder (#5109)

* support clearing flatBuffer builder in js

* remove unused member
 reset force_defaults
dont actually need to clear data in bytebuffer

1 files changed, 18 insertions, 0 deletions

diff --git a/js/flatbuffers.js b/js/flatbuffers.js
index 580020a4..0c970bd8 100644
--- a/js/flatbuffers.js
+++ b/js/flatbuffers.js
@@ -226,6 +226,19 @@ flatbuffers.Builder = function(opt_initial_size) {
   this.force_defaults = false;
 };
 
+flatbuffers.Builder.prototype.clear = function() {
+  this.bb.clear();
+  this.space = this.bb.capacity();
+  this.minalign = 1;
+  this.vtable = null;
+  this.vtable_in_use = 0;
+  this.isNested = false;
+  this.object_start = 0;
+  this.vtables = [];
+  this.vector_num_elems = 0;
+  this.force_defaults = false;
+};
+
 /**
  * In order to save space, fields that are set to their default value
  * don't get serialized into the buffer. Forcing defaults provides a
@@ -816,6 +829,7 @@ flatbuffers.ByteBuffer = function(bytes) {
    * @private
    */
   this.position_ = 0;
+
 };
 
 /**
@@ -828,6 +842,10 @@ flatbuffers.ByteBuffer.allocate = function(byte_size) {
   return new flatbuffers.ByteBuffer(new Uint8Array(byte_size));
 };
 
+flatbuffers.ByteBuffer.prototype.clear = function() {  
+  this.position_ = 0;
+};
+
 /**
  * Get the underlying `Uint8Array`.
  *