Add support for overriding settings per request

lib/application.js

@@ -167,6 +167,10 @@ app.handle = function handle(req, res, callback) {
   if (!res.locals) {
     res.locals = Object.create(null);
   }
+  if (!res.settings) {
+    res.settings = {};
+  }
+  res.settings.__proto__ = this.settings;
 
   this.router.handle(req, res, done);
 };
@@ -226,6 +230,7 @@ app.use = function use(fn) {
       fn.handle(req, res, function (err) {
         req.__proto__ = orig.request;
         res.__proto__ = orig.response;
+        res.settings.__proto__ = orig.settings;
         next(err);
       });
     });
@@ -520,13 +525,23 @@ app.render = function render(name, options, callback) {
   var opts = options;
   var renderOptions = {};
   var view;
+  var self = this;
 
   // support callback function as second arg
   if (typeof options === 'function') {
     done = options;
     opts = {};
   }
 
+  function settings(key) {
+    if (typeof options._settings !== 'undefined') {
+      return options._settings[key];
+    } else {
+      return self.get(key);
+    }
+  }
+  var cacheKey = settings('views') + '/' + name;
+
   // merge app.locals
   merge(renderOptions, this.locals);
 
@@ -545,16 +560,16 @@ app.render = function render(name, options, callback) {
 
   // primed cache
   if (renderOptions.cache) {
-    view = cache[name];
+    view = cache[cacheKey];
   }
 
   // view
   if (!view) {
-    var View = this.get('view');
+    var View = settings('view');
 
     view = new View(name, {
-      defaultEngine: this.get('view engine'),
-      root: this.get('views'),
+      defaultEngine: settings('view engine'),
+      root: settings('views'),
       engines: engines
     });
 
@@ -569,7 +584,7 @@ app.render = function render(name, options, callback) {
 
     // prime the cache
     if (renderOptions.cache) {
-      cache[name] = view;
+      cache[cacheKey] = view;
     }
   }
 

lib/response.js

@@ -160,7 +160,7 @@ res.send = function send(body) {
 
   // populate ETag
   var etag;
-  var generateETag = len !== undefined && app.get('etag fn');
+  var generateETag = len !== undefined && this.settings['etag fn'];
   if (typeof generateETag === 'function' && !this.get('ETag')) {
     if ((etag = generateETag(chunk, encoding))) {
       this.set('ETag', etag);
@@ -213,8 +213,8 @@ res.json = function json(obj) {
 
   // settings
   var app = this.app;
-  var replacer = app.get('json replacer');
-  var spaces = app.get('json spaces');
+  var replacer = this.settings['json replacer'];
+  var spaces = this.settings['json spaces'];
   var body = JSON.stringify(val, replacer, spaces);
 
   // content-type
@@ -249,10 +249,10 @@ res.jsonp = function jsonp(obj) {
 
   // settings
   var app = this.app;
-  var replacer = app.get('json replacer');
-  var spaces = app.get('json spaces');
+  var replacer = this.settings['json replacer'];
+  var spaces = this.settings['json spaces'];
   var body = JSON.stringify(val, replacer, spaces);
-  var callback = this.req.query[app.get('jsonp callback name')];
+  var callback = this.req.query[this.settings['jsonp callback name']];
 
   // content-type
   if (!this.get('Content-Type')) {
@@ -855,6 +855,8 @@ res.render = function render(view, options, callback) {
     self.send(str);
   };
 
+  opts._settings = this.settings;
+
   // render
   app.render(view, opts, done);
 };

test/res.settings.js

@@ -0,0 +1,169 @@
+
+var express = require('..');
+var request = require('supertest');
+
+describe('res', function(){
+  describe('.settings', function(){
+    it('should override app setting', function(done){
+      var app = express();
+      app.set('json spaces', 2);
+      app.get('/', function(req, res){
+        res.settings['json spaces'] = 4;
+        res.json({a:'b'});
+      });
+      request(app)
+      .get('/')
+      .expect(200, '{\n    "a": "b"\n}', done);
+    })
+
+    it('should default to app setting if not overridden', function(done){
+      var app = express();
+      app.set('json spaces', 2);
+      app.get('/', function(req, res){
+        res.send(res.settings['json spaces']);
+      });
+      request(app)
+      .get('/')
+      .expect(200, '2', done)
+    })
+
+    describe('when performing a series of requests', function(){
+      var app = express();
+      app.set('json spaces', 2);
+      app.get('/', function(req, res){
+        res.settings['json spaces'] = 4;
+        res.json({a:'b'});
+      });
+      app.get('/other', function(req, res){
+        res.json({a:'b'});
+      });
+
+      it('should affect settings on the request it is set', function(done){
+        request(app)
+        .get('/')
+        .expect(200, '{\n    "a": "b"\n}', done);
+      })
+
+      it('should not affect settings for other requests', function(done){
+        request(app)
+        .get('/other')
+        .expect(200, '{\n  "a": "b"\n}', done);
+      })
+    }) 
+
+    describe('when "views" is overridden', function(){
+      var app = express();
+      var count = 0;
+
+      function View(name, options){
+        this.name = name;
+        this.path = options.root;
+        count++;
+      }
+
+      View.prototype.render = function(options, fn){
+        fn(null, this.path);
+      };
+
+      app.set('view cache', true);
+      app.set('views', '/a');
+      app.set('view', View);
+
+      app.get('/:use_b', function(req, res) {
+        if (req.params.use_b === 'true') {
+          res.settings['views'] = '/b';
+        }
+        res.render('index');
+      });
+
+      it('should render distinct views with the same name and different "views"', function(done){
+        request(app)
+        .get('/false')
+        .expect(200, '/a', function(err, res) {
+          if (err) return done(err);
+          count.should.equal(1);
+          request(app)
+          .get('/true')
+          .expect(200, '/b', function(err, res) {
+            if (err) return done(err);
+            count.should.equal(2);
+            done();
+          });
+        });
+      });
+
+      it('should cache views with the same name and "views"', function(done){
+        request(app)
+        .get('/false')
+        .expect(200, '/a', function(err, res) {
+          if (err) return done(err);
+          count.should.equal(2);
+          request(app)
+          .get('/true')
+          .expect(200, '/b', function(err, res) {
+            if (err) return done(err);
+            count.should.equal(2);
+            done();
+          });
+        });
+      })
+    })
+
+    describe('with mounted app', function(){
+      it('should default to mounted application settings', function(done){
+        var app = express();
+        app.set('json spaces', 2);
+        var app2 = express();
+        app2.set('json spaces', 4);
+        app2.get('/', function(req, res) {
+          res.json({a:'b'});
+        });
+        app.use('/inner', app2);
+
+        request(app)
+        .get('/inner')
+        .expect(200, '{\n    "a": "b"\n}', done);
+      })
+
+      it('should retain any overridden settings from parent', function(done){
+        var app = express();
+        app.use('/', function(req, res, next) {
+          res.settings['json spaces'] = 4;
+          next();
+        });
+        var app2 = express();
+        app2.get('/', function(req, res) {
+          res.json({a:'b'});
+        });
+        app.use('/inner', app2);
+
+        request(app)
+        .get('/inner')
+        .expect(200, '{\n    "a": "b"\n}', done);
+      })
+
+      it('should default to parent app settings again', function(done){
+        var app = express();
+        app.set('json spaces', 2);
+        var app2 = express();
+        app2.set('json spaces', 4);
+        app2.use('/', function(req, res, next) {
+          res.set('x-ran-inner-middleware', 'true');
+          next();
+        });
+        app2.get('/', function(req, res) {
+          res.json({a:'b'});
+        });
+        app.use('/inner', app2);
+        app.get('/inner/not_really', function(req, res) {
+          res.json({c:'d'});
+        });
+
+        request(app)
+        .get('/inner/not_really')
+        .expect('x-ran-inner-middleware', 'true')
+        .expect(200, '{\n  "c": "d"\n}', done);
+      })
+    })
+  })
+})