Allow override zoom+center or bbox for static named maps previews

lib/cartodb/controllers/base.js

@@ -14,6 +14,9 @@ var REQUEST_QUERY_PARAMS_WHITELIST = [
     'api_key',
     'auth_token',
     'callback',
+    'zoom',
+    'lon',
+    'lat',
     // widgets & filters
     'filters', // json
     'own_filter', // 0, 1

lib/cartodb/controllers/named_maps.js

@@ -140,7 +140,7 @@ NamedMapsController.prototype.staticMap = function(req, res) {
         function prepareImageOptions(err, _namedMapProvider) {
             assert.ifError(err);
             namedMapProvider = _namedMapProvider;
-            self.getStaticImageOptions(cdbUser, namedMapProvider, this);
+            self.getStaticImageOptions(cdbUser, req.params, namedMapProvider, this);
         },
         function getImage(err, imageOpts) {
             assert.ifError(err);
@@ -192,9 +192,37 @@ var DEFAULT_ZOOM_CENTER = {
     }
 };
 
-NamedMapsController.prototype.getStaticImageOptions = function(cdbUser, namedMapProvider, callback) {
+function numMapper(n) {
+    return +n;
+}
+
+NamedMapsController.prototype.getStaticImageOptions = function(cdbUser, params, namedMapProvider, callback) {
     var self = this;
 
+    if ([params.zoom, params.lon, params.lat].map(numMapper).every(Number.isFinite)) {
+        return callback(null, {
+            zoom: params.zoom,
+            center: {
+                lng: params.lon,
+                lat: params.lat
+            }
+        });
+    }
+
+    if (params.bbox) {
+        var bbox = params.bbox.split(',').map(numMapper);
+        if (bbox.length === 4 && bbox.every(Number.isFinite)) {
+            return callback(null, {
+                bounds: {
+                    west: bbox[0],
+                    south: bbox[1],
+                    east: bbox[2],
+                    north: bbox[3]
+                }
+            });
+        }
+    }
+
     step(
         function getTemplate() {
             namedMapProvider.getTemplate(this);
@@ -205,6 +233,9 @@ NamedMapsController.prototype.getStaticImageOptions = function(cdbUser, namedMap
             if (template.view) {
                 var zoomCenter = templateZoomCenter(template.view);
                 if (zoomCenter) {
+                    if (Number.isFinite(+params.zoom)) {
+                        zoomCenter.zoom = +params.zoom;
+                    }
                     return zoomCenter;
                 }
 

test/acceptance/named_maps_static_view.js

@@ -1,3 +1,4 @@
+var qs = require('querystring');
 var testHelper = require('../support/test_helper');
 var RedisPool = require('redis-mpool');
 
@@ -53,10 +54,18 @@ describe('named maps static view', function() {
         templateMaps.delTemplate(username, templateName, done);
     });
 
-    function getStaticMap(callback) {
+    function getStaticMap(params, callback) {
+        if (!callback) {
+            callback = params;
+            params = null;
+        }
 
         var url = '/api/v1/map/static/named/' + templateName + '/640/480.png';
 
+        if (params !== null) {
+            url += '?' + qs.stringify(params);
+        }
+
         var requestOptions = {
             url: url,
             method: 'GET',
@@ -163,4 +172,30 @@ describe('named maps static view', function() {
         });
     });
 
+    it('should return override zoom', function (done) {
+        var view = {
+            bounds: {
+                west: 0,
+                south: 0,
+                east: 45,
+                north: 45
+            },
+            zoom: 4,
+            center: {
+                lng: 40,
+                lat: 20
+            }
+        };
+        templateMaps.addTemplate(username, createTemplate(view), function (err) {
+            if (err) {
+                return done(err);
+            }
+            getStaticMap({ zoom: 3 }, function(err, img) {
+                assert.ok(!err);
+                img.save('/tmp/static.png');
+                assert.imageIsSimilarToFile(img, previewFixture('override-zoom'), IMAGE_TOLERANCE, done);
+            });
+        });
+    });
+
 });