support non-b64 payloads and default to it for the normal api hosts

Author: tdumitrescu

src/mixpanel-core.js

@@ -56,6 +56,8 @@ var IDENTITY_FUNC = function(x) {return x;};
 var NOOP_FUNC = function() {};
 
 /** @const */ var PRIMARY_INSTANCE_NAME = 'mixpanel';
+/** @const */ var PAYLOAD_TYPE_BASE64   = 'base64';
+/** @const */ var PAYLOAD_TYPE_JSON     = 'json';
 
 
 /*
@@ -86,6 +88,7 @@ var DEFAULT_CONFIG = {
     'api_host':                          'https://api-js.mixpanel.com',
     'api_method':                        'POST',
     'api_transport':                     'XHR',
+    'api_payload_format':                PAYLOAD_TYPE_BASE64,
     'app_host':                          'https://mixpanel.com',
     'cdn':                               'https://cdn.mxpnl.com',
     'cross_site_cookie':                 false,
@@ -181,12 +184,6 @@ var create_mplib = function(token, config, name) {
     return instance;
 };
 
-var encode_data_for_request = function(data) {
-    var json_data = _.JSONEncode(data);
-    var encoded_data = _.base64Encode(json_data);
-    return {'data': encoded_data};
-};
-
 // Initialization methods
 
 /**
@@ -236,7 +233,17 @@ MixpanelLib.prototype._init = function(token, config, name) {
     this['config'] = {};
     this['_triggered_notifs'] = [];
 
-    this.set_config(_.extend({}, DEFAULT_CONFIG, config, {
+    var variable_features = {};
+
+    // default to JSON payload for standard mixpanel.com API hosts
+    if (!('api_payload_format' in config)) {
+        var api_host = config['api_host'] || DEFAULT_CONFIG['api_host'];
+        if (api_host.match(/\.mixpanel\.com$/)) {
+            variable_features['api_payload_format'] = PAYLOAD_TYPE_JSON;
+        }
+    }
+
+    this.set_config(_.extend({}, DEFAULT_CONFIG, variable_features, config, {
         'name': name,
         'token': token,
         'callback_fn': ((name === PRIMARY_INSTANCE_NAME) ? name : PRIMARY_INSTANCE_NAME + '.' + name) + '._jsc'
@@ -612,7 +619,7 @@ MixpanelLib.prototype.init_batchers = function() {
                     sendRequestFunc: _.bind(function(data, options, cb) {
                         this._send_request(
                             this.get_config('api_host') + attrs.endpoint,
-                            encode_data_for_request(data),
+                            this._encode_data_for_request(data),
                             options,
                             this._prepare_callback(cb, data)
                         );
@@ -686,6 +693,14 @@ MixpanelLib.prototype.disable = function(events) {
     }
 };
 
+MixpanelLib.prototype._encode_data_for_request = function(data) {
+    var encoded_data = _.JSONEncode(data);
+    if (this.get_config('api_payload_format') === PAYLOAD_TYPE_BASE64) {
+        encoded_data = _.base64Encode(encoded_data);
+    }
+    return {'data': encoded_data};
+};
+
 // internal method for handling track vs batch-enqueue logic
 MixpanelLib.prototype._track_or_batch = function(options, callback) {
     var truncated_data = _.truncate(options.data, 255);
@@ -705,7 +720,7 @@ MixpanelLib.prototype._track_or_batch = function(options, callback) {
             console.log(truncated_data);
             return this._send_request(
                 endpoint,
-                encode_data_for_request(truncated_data),
+                this._encode_data_for_request(truncated_data),
                 send_request_options,
                 this._prepare_callback(callback, truncated_data)
             );