Incorporate New Optimizely endpoint in event dispatcher

lib/plugins/event_dispatcher/index.js

@@ -1,35 +1,54 @@
 var _ = require('lodash/core');
 var bluebird = require('bluebird');
 
+var POST_METHOD = 'POST';
+var GET_METHOD = 'GET';
+
 module.exports = {
   /**
    * Sample event dispatcher implementation for tracking impression and conversions
    * Users of the SDK can provide their own implementation
-   * @param  {string} url
-   * @param  {Object} params
+   * @param  {Object} eventObj
    * @return {Promise<Object>}
    */
-  dispatchEvent: function(url, params) {
-    return new bluebird(function(resolve, reject) {
-      // add param for cors headers to be sent by the log endpoint
-      url += '?wxhr=true';
-      if (params) {
-        url += '&' + toQueryString(params);
-      }
+  dispatchEvent: function(eventObj) {
+    var url = eventObj.url;
+    var params = eventObj.params;
+
+    if (eventObj.httpVerb === POST_METHOD) {
+      return new bluebird(function(resolve, reject) {
+
+        var req = new XMLHttpRequest();
+        req.open(POST_METHOD, url, true);
+        req.setRequestHeader('Content-Type', 'application/json');
+        req.addEventListener('load', function (evt) {
+          var responseObj = evt.target.responseText;
+          resolve(responseObj);
+        });
+        req.send(JSON.stringify(params));
+      })
+    } else {
+      return new bluebird(function (resolve, reject) {
+        // add param for cors headers to be sent by the log endpoint
+        url += '?wxhr=true';
+        if (params) {
+          url += '&' + toQueryString(params);
+        }
 
-      var req = new XMLHttpRequest();
-      req.open('GET', url, true);
-      req.addEventListener('load', function(evt) {
-        var responseObj = JSON.parse(evt.target.responseText);
-        resolve(responseObj);
+        var req = new XMLHttpRequest();
+        req.open(GET_METHOD, url, true);
+        req.addEventListener('load', function (evt) {
+          var responseObj = JSON.parse(evt.target.responseText);
+          resolve(responseObj);
+        });
+        req.send();
       });
-      req.send();
-    });
+    }
   },
 };
 
 var toQueryString = function(obj) {
-  return _.map(obj, function(v, k){
+  return _.map(obj, function(v, k) {
     return encodeURIComponent(k) + '=' + encodeURIComponent(v);
   }).join('&');
 };