use angulars.toJson in the angular version of the client

src/elasticsearch.angular.js

@@ -6,6 +6,8 @@
  */
 var AngularConnector = require('./lib/connectors/angular');
 var Client = require('./lib/client');
+var _ = require('./lib/utils');
+var JsonSerializer = require('./lib/serializers/json');
 
 process.angular_build = true;
 
@@ -20,9 +22,25 @@ angular.module('elasticsearch', [])
       config.defer = function () {
         return $q.defer();
       };
+      config.serializer = AngularSerializer;
       return new Client(config);
     };
 
+    _.inherits(AngularSerializer, JsonSerializer);
+    function AngularSerializer() {}
+    // mimic the JsonSerializer's encode method, but use angular's toJson instead
+    AngularSerializer.prototype.encode = function (val) {
+      switch (typeof val) {
+      case 'string':
+        return val;
+      case 'object':
+        if (val) return angular.toJson(val);
+        /* falls through */
+      default:
+        return;
+      }
+    };
+
     factory.errors = require('./lib/errors');
     factory.ConnectionPool = require('./lib/connection_pool');
     factory.Transport = require('./lib/transport');