Applied approach similar to static image options

lib/cartodb/controllers/named_maps.js

@@ -10,7 +10,7 @@ var cors = require('../middleware/cors');
 var userMiddleware = require('../middleware/user');
 
 function NamedMapsController(authApi, pgConnection, namedMapProviderCache, tileBackend, previewBackend,
-                             surrogateKeysCache, tablesExtentApi, metadataBackend) {
+                             surrogateKeysCache, tablesExtentApi, metadataBackend, templateMaps) {
     BaseController.call(this, authApi, pgConnection);
 
     this.namedMapProviderCache = namedMapProviderCache;
@@ -19,6 +19,7 @@ function NamedMapsController(authApi, pgConnection, namedMapProviderCache, tileB
     this.surrogateKeysCache = surrogateKeysCache;
     this.tablesExtentApi = tablesExtentApi;
     this.metadataBackend = metadataBackend;
+    this.templateMaps = templateMaps;
 }
 
 util.inherits(NamedMapsController, BaseController);
@@ -126,6 +127,23 @@ NamedMapsController.prototype.staticMap = function(req, res) {
         function reqParams() {
             self.req2params(req, this);
         },
+        function getLayerFilterFromPreviewLayers (err) {
+            assert.ifError(err);
+
+            var next = this;
+
+            self.getLayerFilterFromPreviewLayers(cdbUser, req.params.template_id, next);
+        },
+        function applyPreviewLayers (err, layerVisibilityFilter) {
+            assert.ifError(err);
+
+            if (layerVisibilityFilter) {
+                // overwrite 'all' default filter
+                req.params.layer = layerVisibilityFilter;
+            }
+
+            return true;
+        },
         function getNamedMapProvider(err) {
             assert.ifError(err);
             self.namedMapProviderCache.get(
@@ -137,13 +155,9 @@ NamedMapsController.prototype.staticMap = function(req, res) {
                 this
             );
         },
-        function layerVisibility(err, namedMapProvider) {
+        function prepareImageOptions(err, _namedMapProvider) {
             assert.ifError(err);
-            return decorateNamedMapProviderWithLayerVisibility(namedMapProvider);
+            namedMapProvider = _namedMapProvider;
-        },
-        function prepareImageOptions(err, decoratedNamedMapProvider) {
-            assert.ifError(err);
-            namedMapProvider = decoratedNamedMapProvider;
             self.getStaticImageOptions(cdbUser, req.params, namedMapProvider, this);
         },
         function getImage(err, imageOpts) {
@@ -188,6 +202,53 @@ NamedMapsController.prototype.staticMap = function(req, res) {
     );
 };
 
+NamedMapsController.prototype.getLayerFilterFromPreviewLayers = function (cdbUser, template_id, callback) {
+    var self = this;
+
+    step(
+        function getTemplate () {
+            var next = this;
+
+            self.templateMaps.getTemplate(cdbUser, template_id, next);
+        },
+        function getLayerVisivilityFilter (err, template) {
+            assert.ifError(err);
+
+            var next = this;
+
+            if (!template || !template.view || !template.view.preview_layers) {
+               return next();
+            }
+
+            var previewLayers = template.view.preview_layers;
+            var layerVisibilityFilter = [];
+
+            template.layergroup.layers.forEach(function (layer, index) {
+                if (previewLayers[''+index] !== false && previewLayers[layer.id] !== false) {
+                    layerVisibilityFilter.push(''+index);
+                }
+            });
+
+            if (!layerVisibilityFilter.length) {
+                return next();
+            }
+
+            next(null, layerVisibilityFilter);
+        },
+        function finish (err, layerVisibilityFilter) {
+            if (err) {
+                return callback(err);
+            }
+
+            if (!layerVisibilityFilter) {
+                return callback();
+            }
+
+            callback(null, layerVisibilityFilter.join(','));
+        }
+    );
+};
+
 var DEFAULT_ZOOM_CENTER = {
     zoom: 1,
     center: {
@@ -200,46 +261,6 @@ function numMapper(n) {
     return +n;
 }
 
-function decorateNamedMapProviderWithLayerVisibility (mamedMapProvider) {
-    var orginalGetMapConfig = mamedMapProvider.getMapConfig.bind(mamedMapProvider);
-
-    mamedMapProvider.getMapConfig = function (callback) {
-        mamedMapProvider.getTemplate(function (err, template) {
-            if (err) {
-                return callback(err);
-            }
-
-            if (!template.preview_layers) {
-                return orginalGetMapConfig(callback);
-            }
-
-            var previewLayers = template.preview_layers;
-            orginalGetMapConfig(function (err, mapConfig, rendererParams, context) {
-                if (err) {
-                    return callback(err);
-                }
-
-                var layerVisibilityFilter = [];
-
-                mapConfig.getLayers().forEach(function (layer, index) {
-                    if (previewLayers[''+index] !== false && previewLayers[layer.id] !== false) {
-                        layerVisibilityFilter.push(''+index);
-                    }
-                });
-
-                if (layerVisibilityFilter.length) {
-                    // overwrite 'all' default filter
-                    rendererParams.layer = layerVisibilityFilter.join(',');
-                }
-
-                callback(null, mapConfig, rendererParams, context);
-            });
-        });
-    };
-
-    return mamedMapProvider;
-}
-
 NamedMapsController.prototype.getStaticImageOptions = function(cdbUser, params, namedMapProvider, callback) {
     var self = this;