Use req2params middleware for layergroup create endpoint

lib/cartodb/controllers/map.js

@@ -20,6 +20,7 @@ var NamedMapsCacheEntry = require('../cache/model/named_maps_entry');
 var NamedMapMapConfigProvider = require('../models/mapconfig/provider/named-map-provider');
 var CreateLayergroupMapConfigProvider = require('../models/mapconfig/provider/create-layergroup-provider');
 
+const req2paramsMiddleware = require('../middleware/req2params-middleware');
 
 /**
  * @param {AuthApi} authApi
@@ -52,6 +53,7 @@ function MapController(authApi, pgConnection, templateMaps, mapBackend, metadata
     this.resourceLocator = new ResourceLocator(global.environment);
 
     this.statsBackend = statsBackend;
+    this.req2paramsMiddleware = req2paramsMiddleware(authApi, pgConnection);
 }
 
 util.inherits(MapController, BaseController);
@@ -60,8 +62,21 @@ module.exports = MapController;
 
 
 MapController.prototype.register = function(app) {
-    app.get(app.base_url_mapconfig, cors(), userMiddleware, this.createGet.bind(this));
-    app.post(app.base_url_mapconfig, cors(), userMiddleware, this.createPost.bind(this));
+    app.get(
+        app.base_url_mapconfig,
+        cors(),
+        userMiddleware,
+        this.req2paramsMiddleware,
+        this.createGet.bind(this)
+    );
+    app.post(
+        app.base_url_mapconfig,
+        cors(),
+        userMiddleware,
+        this.req2paramsMiddleware,
+        this.createPost.bind(this)
+    );
+
     app.get(app.base_url_templated + '/:template_id/jsonp', cors(), userMiddleware, this.jsonp.bind(this));
     app.post(app.base_url_templated + '/:template_id', cors(), userMiddleware, this.instantiate.bind(this));
     app.options(app.base_url_mapconfig, cors('Content-Type'));
@@ -70,8 +85,7 @@ MapController.prototype.register = function(app) {
 MapController.prototype.createGet = function(req, res, next){
     req.profiler.start('windshaft.createmap_get');
 
-    this.create(req, res, function createGet$prepareConfig(err, req) {
-        assert.ifError(err);
+    this.create(req, res, function createGet$prepareConfig(req) {
         if ( ! req.params.config ) {
             throw new Error('layergroup GET needs a "config" parameter');
         }
@@ -82,8 +96,7 @@ MapController.prototype.createGet = function(req, res, next){
 MapController.prototype.createPost = function(req, res, next) {
     req.profiler.start('windshaft.createmap_post');
 
-    this.create(req, res, function createPost$prepareConfig(err, req) {
-        assert.ifError(err);
+    this.create(req, res, function createPost$prepareConfig(req) {
         if (!req.is('application/json')) {
             throw new Error('layergroup POST data must be of type application/json');
         }
@@ -132,10 +145,10 @@ MapController.prototype.create = function(req, res, prepareConfigFn, next) {
     var context = {};
 
     step(
-        function setupParams(){
-            self.req2params(req, res, this);
+        function prepareConfig () {
+            const requestMapConfig = prepareConfigFn(req);
+            return requestMapConfig;
         },
-        prepareConfigFn,
         function prepareAdapterMapConfig(err, requestMapConfig) {
             assert.ifError(err);
             context.analysisConfiguration = {