Middlewarify static-api (bbox/center) endpoints

lib/cartodb/controllers/layergroup.js

@@ -89,7 +89,8 @@ LayergroupController.prototype.register = function(app) {
         userMiddleware,
         allowQueryParams(['layer']),
         this.prepareContext,
-        this.center.bind(this)
+        this.getMapStoreMapConfigProvider(this.mapStore, this.userLimitsApi),
+        this.center(this.previewBackend)
     );
 
     app.get(
@@ -98,7 +99,8 @@ LayergroupController.prototype.register = function(app) {
         userMiddleware,
         allowQueryParams(['layer']),
         this.prepareContext,
-        this.bbox.bind(this)
+        this.getMapStoreMapConfigProvider(this.mapStore, this.userLimitsApi),
+        this.bbox(this.previewBackend)
     );
 
     // Undocumented/non-supported API endpoint methods.
@@ -325,56 +327,74 @@ LayergroupController.prototype.finalizeGetTileOrGrid = function(err, req, res, t
     }
 };
 
-LayergroupController.prototype.bbox = function(req, res, next) {
-    this.staticMap(req, res, +req.params.width, +req.params.height, {
-        west: +req.params.west,
-        north: +req.params.north,
-        east: +req.params.east,
-        south: +req.params.south
-    }, null, next);
-};
+LayergroupController.prototype.center = function (previewBackend) {
+    return function centerMiddleware (req, res, next) {
+        const width = +req.params.width;
+        const height = +req.params.height;
+        const zoom = +req.params.z;
+        const center = {
+            lng: +req.params.lng,
+            lat: +req.params.lat
+        };
 
-LayergroupController.prototype.center = function(req, res, next) {
-    this.staticMap(req, res, +req.params.width, +req.params.height, +req.params.z, {
-        lng: +req.params.lng,
-        lat: +req.params.lat
-    }, next);
-};
+        const format = req.params.format === 'jpg' ? 'jpeg' : 'png';
 
-LayergroupController.prototype.staticMap = function(req, res, width, height, zoom /* bounds */, center, next) {
-    var format = req.params.format === 'jpg' ? 'jpeg' : 'png';
-    // We force always the tile to be generated using PNG because
-    // is the only format we support by now
-    res.locals.format = 'png';
-    res.locals.layer = res.locals.layer || 'all';
+        // We force always the tile to be generated using PNG because
+        // is the only format we support by now
+        res.locals.format = 'png';
+        res.locals.layer = res.locals.layer || 'all';
 
-    var self = this;
+        const { mapConfigProvider } = res.locals;
 
-    step(
-        function getImage() {
-            if (center) {
-                self.previewBackend.getImage(
-                    new MapStoreMapConfigProvider(self.mapStore, res.locals.user, self.userLimitsApi, res.locals),
-                    format, width, height, zoom, center, this);
-            } else {
-                self.previewBackend.getImage(
-                    new MapStoreMapConfigProvider(self.mapStore, res.locals.user, self.userLimitsApi, res.locals),
-                    format, width, height, zoom /* bounds */, this);
-            }
-        },
-        function handleImage(err, image, headers, stats) {
+        previewBackend.getImage(mapConfigProvider, format, width, height, zoom, center, (err, image, headers, stats) => {
             req.profiler.done('render-' + format);
             req.profiler.add(stats || {});
 
             if (err) {
                 err.label = 'STATIC_MAP';
-                next(err);
-            } else {
-                res.set('Content-Type', headers['Content-Type'] || 'image/' + format);
-                self.sendResponse(req, res, image, 200);
+                return next(err);
             }
-        }
-    );
+
+            res.set('Content-Type', headers['Content-Type'] || 'image/' + format);
+            this.sendResponse(req, res, image, 200);
+        });
+    }.bind(this);
+};
+
+LayergroupController.prototype.bbox = function (previewBackend) {
+    return function bboxMiddleware (req, res, next) {
+        const width = +req.params.width;
+        const height = +req.params.height;
+        const bounds = {
+            west: +req.params.west,
+            north: +req.params.north,
+            east: +req.params.east,
+            south: +req.params.south
+        };
+
+        const format = req.params.format === 'jpg' ? 'jpeg' : 'png';
+
+        // We force always the tile to be generated using PNG because
+        // is the only format we support by now
+        res.locals.format = 'png';
+        res.locals.layer = res.locals.layer || 'all';
+
+        const { mapConfigProvider } = res.locals;
+
+        previewBackend.getImage(mapConfigProvider, format, width, height, bounds, (err, image, headers, stats) => {
+            req.profiler.done('render-' + format);
+            req.profiler.add(stats || {});
+
+            if (err) {
+                err.label = 'STATIC_MAP';
+                return next(err);
+            }
+
+            res.set('Content-Type', headers['Content-Type'] || 'image/' + format);
+
+            this.sendResponse(req, res, image, 200);
+        });
+    }.bind(this);
 };
 
 LayergroupController.prototype.sendResponse = function(req, res, body, status, headers) {