Added res.locals.use(). Closes expressjs#1120

lib/application.js

@@ -14,6 +14,7 @@ var connect = require('connect')
   , methods = Router.methods.concat('del', 'all')
   , middleware = require('./middleware')
   , debug = require('debug')('express:application')
+  , locals = require('./utils').locals
   , View = require('./view')
   , url = require('url')
   , utils = connect.utils
@@ -64,25 +65,6 @@ app.defaultConfiguration = function(){
   this.use(connect.query());
   this.use(middleware.init(this));
 
-  // app locals
-  this.locals = function(obj){
-    for (var key in obj) self.locals[key] = obj[key];
-    return self;
-  };
-
-  // response locals
-  this.locals.use = function(fn){
-    if (3 == fn.length) {
-      self.viewCallbacks.push(fn);
-    } else {
-      self.viewCallbacks.push(function(req, res, done){
-        fn(req, res);
-        done();
-      });
-    }
-    return this;
-  };
-
   // inherit view callbacks
   this.on('mount', function(parent){
     this.request.__proto__ = parent.request;
@@ -101,6 +83,9 @@ app.defaultConfiguration = function(){
     return this._router.middleware;
   });
 
+  // setup locals
+  this.locals = locals(this);
+
   // default locals
   this.locals.settings = this.settings;
 

lib/middleware.js

@@ -1,10 +1,16 @@
 
 /*!
  * Express - middleware
- * Copyright(c) 2010-2011 TJ Holowaychuk <tj@vision-media.ca>
+ * Copyright(c) 2010-2012 TJ Holowaychuk <tj@vision-media.ca>
  * MIT Licensed
  */
 
+/**
+ * Module dependencies.
+ */
+
+var utils = require('./utils');
+
 /**
  * Initialization middleware, exposing the
  * request and response to eachother, as well
@@ -26,10 +32,7 @@ exports.init = function(app){
     req.__proto__ = app.request;
     res.__proto__ = app.response;
 
-    res.locals = function(obj){
-      for (var key in obj) res.locals[key] = obj[key];
-      return res;
-    };
+    res.locals = utils.locals(res);
 
     next();
   }

lib/response.js

@@ -627,7 +627,7 @@ res.render = function(view, options, fn){
   }
 
   // invoke view callbacks
-  var callbacks = app.viewCallbacks
+  var callbacks = app.viewCallbacks.concat(self.viewCallbacks)
     , pending = callbacks.length
     , len = pending
     , done;

lib/utils.js

@@ -11,6 +11,39 @@
 
 var mime = require('mime');
 
+/**
+ * Make `locals()` bound to the given `obj`.
+ *  
+ * This is used for `app.locals` and `res.locals`. 
+ *
+ * @param {Object} obj
+ * @return {Function}
+ * @api private
+ */
+
+exports.locals = function(obj){
+  obj.viewCallbacks = obj.viewCallbacks || [];
+
+  function locals(obj){
+    for (var key in obj) locals[key] = obj[key];
+    return obj;
+  };
+
+  locals.use = function(fn){
+    if (3 == fn.length) {
+      obj.viewCallbacks.push(fn);
+    } else {
+      obj.viewCallbacks.push(function(req, res, done){
+        fn(req, res);
+        done();
+      });
+    }
+    return obj;
+  };
+
+  return locals;
+};
+
 /**
  * Check if `path` looks absolute.
  *

test/res.locals.use.js

@@ -0,0 +1,104 @@
+
+var express = require('../')
+  , request = require('./support/http');
+
+describe('res', function(){
+  describe('.locals.use(fn)', function(){
+    it('should run in parallel on res.render()', function(done){
+      var app = express();
+      var calls = [];
+      app.set('views', __dirname + '/fixtures');
+
+      app.locals.first = 'tobi';
+
+      app.use(function(req, res, next){
+        res.locals.use(function(req, res, done){
+          process.nextTick(function(){
+            calls.push('one');
+            res.locals.last = 'holowaychuk';
+            done();
+          });
+        });
+        next();
+      });
+
+      app.use(function(req, res, next){
+        res.locals.use(function(req, res, done){
+          process.nextTick(function(){
+            calls.push('two');
+            res.locals.species = 'ferret';
+            done();
+          });
+        });
+        next();
+      });
+
+      app.use(function(req, res){
+        calls.push('render');
+        res.render('pet.jade');
+      });
+
+      request(app)
+      .get('/')
+      .end(function(res){
+        calls.should.eql(['render', 'one', 'two']);
+        res.body.should.equal('<p>tobi holowaychuk is a ferret</p>');
+        done();
+      })
+    })
+
+    describe('with arity < 3', function(){
+      it('should done() for you', function(done){
+        var app = express();
+
+        app.set('views', __dirname + '/fixtures');
+        app.locals.first = 'tobi';
+
+        app.use(function(req, res, next){
+          app.locals.use(function(req, res){
+            res.locals.last = 'holowaychuk';
+            res.locals.species = 'ferret';
+          });
+          next();
+        });
+
+        app.use(function(req, res){
+          res.render('pet.jade');
+        });
+
+        request(app)
+        .get('/')
+        .end(function(res){
+          res.body.should.equal('<p>tobi holowaychuk is a ferret</p>');
+          done();
+        })
+      })
+    })
+
+    it('should not override res.render() locals', function(done){
+      var app = express();
+
+      app.set('views', __dirname + '/fixtures');
+      app.locals.first = 'tobi';
+
+      app.use(function(req, res, next){
+        app.locals.use(function(req, res){
+          res.locals.last = 'holowaychuk';
+          res.locals.species = 'ferret';
+        });
+        next();
+      });
+
+      app.use(function(req, res){
+        res.render('pet.jade', { last: 'ibot' });
+      });
+
+      request(app)
+      .get('/')
+      .end(function(res){
+        res.body.should.equal('<p>tobi ibot is a ferret</p>');
+        done();
+      })
+    })
+  })
+})