Improve koa example

todo-angular-koa/app.js

@@ -3,8 +3,9 @@ var koa = require('koa');
 // Middleware and helpers
 var serve = require('koa-static');
 var parse = require('co-body');
-var router = require('koa-router');
-var http = require('http');
+var Router = require('koa-router');
+var logger = require('koa-logger');
+var co = require('co');
 
 // Import rethinkdb
 var r = require('rethinkdb');
@@ -14,147 +15,103 @@ var config = require(__dirname+"/config.js");
 
 var app = koa();
 
+//
+// MIDDLEWARE
+//
+
 // Static content
 app.use(serve(__dirname+'/public'));
 
-// Create a RethinkDB connection
-app.use(createConnection);
-
-app.use(router(app));
-app.get('/todo/get', get);
-app.put('/todo/new', create);
-app.post('/todo/update', update);
-app.post('/todo/delete', del);
-
-// Close the RethinkDB connection
-app.use(closeConnection);
-
-/*
- * Create a RethinkDB connection, and save it in req._rdbConn
- */
-function* createConnection(next) {
-    try{
-        var conn = yield r.connect(config.rethinkdb);
-        this._rdbConn = conn;
-    }
-    catch(err) {
-        this.status = 500;
-        this.body = err.message || http.STATUS_CODES[this.status];
+// Log requests
+app.use(logger());
+
+// Parse application/json bodies into this.request.body
+app.use(function* (next) {
+  this.request.body = yield parse.json(this);
+  yield next;
+});
+
+// Create a RethinkDB connection, save it in the koa context, and ensure it closes
+app.use(function* wrapConnection(next) {
+    this.state.conn = yield r.connect(config.rethinkdb);
+    // No matter what happens downstream, always close the connection
+    try {
+        yield next;
+    } finally {
+        this.state.conn.close();
     }
-    yield next;
-}
+});
+
+//
+// ROUTES
+//
+
+var router = Router();
 
 // Retrieve all todos
-function* get(next) {
-    try{
-        var cursor = yield r.table('todos').orderBy({index: "createdAt"}).run(this._rdbConn);
-        var result = yield cursor.toArray();
-        this.body = JSON.stringify(result);
-    }
-    catch(e) {
-        this.status = 500;
-        this.body = e.message || http.STATUS_CODES[this.status];
-    }
-    yield next;
-}
+router.get('/todo/get', function* get(next) {
+    var cursor = yield r.table('todos').orderBy({index: "createdAt"}).run(this.state.conn);
+    var result = yield cursor.toArray();
+    this.body = result;
+})
 
 // Create a new todo
-function* create(next) {
-    try{
-        var todo = yield parse(this);
-        todo.createdAt = r.now(); // Set the field `createdAt` to the current time
-        var result = yield r.table('todos').insert(todo, {returnChanges: true}).run(this._rdbConn);
-
-        todo = result.changes[0].new_val; // todo now contains the previous todo + a field `id` and `createdAt`
-        this.body = JSON.stringify(todo);
-    }
-    catch(e) {
-        this.status = 500;
-        this.body = e.message || http.STATUS_CODES[this.status];
-    }
-    yield next;
-}
+router.put('/todo/new', function* create(next) {
+    var todo = this.request.body;
+    todo.createdAt = r.now(); // Set the field `createdAt` to the current time
+    var result = yield r.table('todos').insert(todo, {returnChanges: true}).run(this.state.conn);
+
+    todo = result.changes[0].new_val; // todo now contains the previous todo + a field `id` and `createdAt`
+    this.body = todo;
+});
 
 // Update a todo
-function* update(next) {
-    try{
-        var todo = yield parse(this);
-        delete todo._saving;
-        if ((todo == null) || (todo.id == null)) {
-            throw new Error("The todo must have a field `id`.");
-        }
-
-        var result = yield r.table('todos').get(todo.id).update(todo, {returnChanges: true}).run(this._rdbConn);
-        this.body = JSON.stringify(result.changes[0].new_val);
-    }
-    catch(e) {
-        this.status = 500;
-        this.body = e.message || http.STATUS_CODES[this.status];
-    }
-    yield next;
-}
+router.post('/todo/update', function* update(next) {
+    var todo = this.request.body;
+    this.assert(todo && todo.id, 400, 'todo must have field `id`');
+    delete todo._saving;
+    var result = yield r.table('todos').get(todo.id).update(todo, {returnChanges: true}).run(this.state.conn);
+    this.body = result.changes[0].new_val;
+});
 
 // Delete a todo
-function* del(next) {
-    try{
-        var todo = yield parse(this);
-        if ((todo == null) || (todo.id == null)) {
-            throw new Error("The todo must have a field `id`.");
-        }
-        var result = yield r.table('todos').get(todo.id).delete().run(this._rdbConn);
-        this.body = "";
-    }
-    catch(e) {
-        this.status = 500;
-        this.body = e.message || http.STATUS_CODES[this.status];
-    }
-    yield next;
-}
-
-/*
- * Close the RethinkDB connection
- */
-function* closeConnection(next) {
-    this._rdbConn.close();
-}
-
-r.connect(config.rethinkdb, function(err, conn) {
-    if (err) {
-        console.log("Could not open a connection to initialize the database");
-        console.log(err.message);
-        process.exit(1);
-    }
+router.post('/todo/delete', function* del(next) {
+    var todo = this.request.body;
+    this.assert(todo && todo.id, 400, 'todo must have field `id`');
+    var result = yield r.table('todos').get(todo.id).delete().run(this.state.conn);
+    this.body = '';
+});
 
-    r.table('todos').indexWait('createdAt').run(conn).then(function(err, result) {
+// Mount our router
+app.use(router.routes());
+
+// Setup database and launch the koa server
+var conn;
+co(function* () {
+    try {
+        conn = yield r.connect(config.rethinkdb);
+    } catch(err) {
+        console.error("Could not open a connection to initialize the database");
+        throw err;
+    }
+    try {
+        yield r.table('todos').indexWait('createdAt').run(conn);
         console.log("Table and index are available, starting koa...");
-        startKoa();
-    }).error(function(err) {
+    } catch(err) {
         // The database/table/index was not available, create them
-        r.dbCreate(config.rethinkdb.db).run(conn).finally(function() {
-            return r.tableCreate('todos').run(conn)
-        }).finally(function() {
-            r.table('todos').indexCreate('createdAt').run(conn);
-        }).finally(function(result) {
-            r.table('todos').indexWait('createdAt').run(conn)
-        }).then(function(result) {
-            console.log("Table and index are available, starting koa...");
-            startKoa();
-            conn.close();
-        }).error(function(err) {
-            if (err) {
-                console.log("Could not wait for the completion of the index `todos`");
-                console.log(err);
-                process.exit(1);
-            }
-            console.log("Table and index are available, starting koa...");
-            startKoa();
-            conn.close();
-        });
+        yield r.dbCreate(config.rethinkdb.db).run(conn);
+        yield r.tableCreate('todos').run(conn);
+        yield r.table('todos').indexCreate('createdAt').run(conn);
+        yield r.table('todos').indexWait('createdAt').run(conn)
+        console.log("Table and index are available, starting koa...");
+    }
+}).then(function () {
+    conn.close();
+    app.listen(config.koa.port, function() {
+        console.log('Listening on port', config.koa.port);
     });
+}).catch(function (err) {
+    conn.close();
+    console.error(err);
+    process.exit(1);
 });
-
-
-function startKoa() {
-    app.listen(config.koa.port);
-    console.log('Listening on port '+config.koa.port);
-}

todo-angular-koa/package.json

@@ -1,15 +1,14 @@
 {
-    "name": "todo"
-  , "version": "0.0.2"
-  , "private": true
-  , "dependencies": {
-      "koa": "0.6.0"
-    , "koa-static": "1.4.2"
-    , "koa-router": "3.1.4"
-    , "co-body": "0.0.1"
-    , "co": "3.0.2"
-    , "body-parser": "1.0.2"
-    , "rethinkdb": ">=2.1.1"
-    , "co-assert-timeout": "0.0.4"
+  "name": "todo",
+  "version": "0.0.2",
+  "private": true,
+  "dependencies": {
+    "co": "4.6.0",
+    "co-body": "4.2.0",
+    "koa": "1.2.0",
+    "koa-logger": "^1.3.0",
+    "koa-router": "5.3.0",
+    "koa-static": "1.4.2",
+    "rethinkdb": ">=2.1.1"
   }
 }

todo-angular-koa/public/js/controllers/todoCtrl.js

@@ -111,7 +111,7 @@ todomvc.controller('TodoCtrl', function TodoCtrl($scope, $routeParams, todoStora
 	};
 
 	$scope.clearCompletedTodos = function () {
-		$scope.todos = todos.filter(function (val) {
+		$scope.todos = $scope.todos.filter(function (val) {
 			return !val.completed;
 		});
 	};