Node js Express Parallel Requests - node.js

I develop an Nodejs app.I'm using ExpressJS.I've madesome routes to GET data from db.I want to get that data async. In other words i want that requests to be executed on parrallel. I've foundsome examples with callbacks but doesn't help me.Here is an example of request:
var express = require('express');
var app = express();
app.get("/api",function(req,res){
console.log("Test!");
})
How should I write this to be executed async?I want to use node js module async.

This is the example
var app = require('express')();
var path = require('path');
var config = require('dotenv').config({
path: path.join(__dirname + '/../../../.env')
});
app.get('/', function(req, res) {
res.sendFile(path.join(__dirname + '/index.html'));
});

Related

how to create a nodeJS module with expressJS

I'm making a nodeJS module, and I want to use expressJS as a framework for it.
I'm trying to see, how I could go by, including a function inside and app.get(); and call it via another file, such as the actual app.
var express = require("express");
var app = express();
app.get("/", function (req, res) {
exports.type = function (text) {
console.log(req.ip);
console.log(text);
}
});
now when I use this, and i call it on the actual app like:
var web = require("directory_to_file");
var express = require("express");
var app = express();
var http = require("http").Server(app);
app.get("/", function (req, res) {
web.type("Hello, world");
});
http.listen(10022, function () {
console.log("server is up");
});
I get an error:
TypeError: Property 'type' of object #<Object> is not a function
anyone know a way to make it so I can call the function?
There are generally two things you want to export as a module - an API and a Middleware. The classic example of middleware is an authentication module. To do the middleware, just export the middleware. I tend to do a little more than that so I can configure the middleware later. Something along the lines of this:
module.exports = exports = function(config) {
// Do something with config here
return function(req, res, next) {
// your middleware here
};
};
You can then use your middleware in your main program like this:
var app = require('express')(),
mymodule = require('./mymodule');
var config = {}; // replace with whatever config you need
app.use(mymodule(config));
app.listen(process.env.PORT || 3000);
To implement an API, you will create a Router object, then attach your routes to the Router object. You can then "mount" your router in your main program. For example, you could have a file called 'myroutes.js' with the following contents:
var express = require('express'),
myroutes = express.Router();
myroutes.get('/foo', (req, res) => {
res.status(200).type('application/json').send({ myparam: 'foo' });
});
module.exports = exports = myroutes;
Have the following in your main program:
var app = require('express')(),
myroutes = require('./myroutes');
app.use('/api', require('./myroutes'));
app.listen(process.env.PORT || 3000);
Here, in 'myroutes.js', I'm defining a sub-route of /foo and then in the main program, I'm mounting that on /api - so I would access /api/foo to access that API.
In your directory_to_file you are only exporting on app.get('/') which will never be called.
You could add in your directory_to_file the following code
var express = require('express');
var router = express.Router();
router.get('/', function(req, server) {
console.log(req.ip);
});
module.exports = router;
And in your main file you could use app.use('/', web)
A short explanation:
You are creating a new express app / config in your directory_to_file file which won't be launched or used. So your app.get event won't be fired once.
That's why web.type is not a function. You are not exporting anything.
Use the way I provided. This is a commonly used method.
You could call the code I provided a "route". Create multiple routes / route files and include them in your main method.
Your code just looks confused. If I understand you correctly, what you are really trying to do (at least in Node/express terminology) is write your own middleware.
Express is designed with this in mind and it's pretty straightforward e.g.
ipLogger.js
module.exports = function(req, res, next) {
console.log(req.ip);
next();
}
app.js
var http = require("http")
, express = require("express");
, app = express()
, server = http.Server(app)
, ipLogger = require("./ipLogger.js");
app.use(ipLogger()); // log IP of all requests
// handle routes
server.listen(10022, function() {
console.log("server is up");
});

require() in node.js is not working and returns error?

I have looked through stackoverflow and read about require. However I cannot understand why my require function does not run.
app.js code:
var http = require('http');
var express = require("express");
var app = express();
//Twitter Search -------------------
app.get("/tweet, function(req,res){
var twiter = require('twiter.js');
});
app.listen(3000);
twitter.js code:
console.log("twitter.js ran");
Make sure both app.js and twitter.js in same directory
And add ./ before it. Just use following
var twitter = require('./twitter'); // .js extension is not necessary
Also as alexey mentioned. twiter is not same as twitter :)
Take care of your typos. (I think I'm too lazy to read it carefully)
app.js
var http = require('http');
var express = require("express");
var app = express();
//Twitter Search -------------------
app.get("/tweet", function (req, res) {
var twitter = require('./twitter');
twitter.log();
});
app.listen(3000);
twitter.js should be exposed using module.exports
var twitter = {
log: function () {
console.log('twitter is loaded');
}
};
module.exports = twitter;
This should now print "twitter is loaded" in your console, when you visit localhost:3000/tweet

How to efficiently separate routing code

Dumb/Newb question...
I am learning/working on an API in Node / Express4 and I would like to break my routes out into another module. I have it working with the following code, but it seems awkward to me to keep re-using the require('express') statement... Is there a way to move more of the code from the routes.js file into server.js and still keep my .get and .post statements in the routes module? Thanks in advance!
server.js:
'use strict';
var express = require('express');
var routes = require('./routes');
var app = express();
app.use('/api', routes);
app.listen(3000, function() {
console.log('Listening);
});
routes.js
var express = require('express'); // how do I get rid of this line?
var router = express.Router(); // can I move this to server.js?
var apiRoute = router.route('');
apiRoute.get(function (req, res) {
res.send('api GET request received');
});
module.exports = router;
Your on the right track. Its actually cool to reuse the var express = require('express'); statement each time you need it. Importing, ( requiring ), modules is a cornerstone of modular development and allows you to maintain a separation of concerns with in the files of your project.
As far as modularly adding routes is concerned: The issue is that routes.js is misleading.
In order to modularly separate out your routes you should use several modules named <yourResource>.js. Those modules would contain all of the routing code as well as any other configuration or necessary functions. Then you would attach them in app.js with:
var apiRoute = router.route('/api');
apiRoute.use('/<yourResource', yourResourceRouter);
For example, if you had a resource bikes:
In app.js or even a module api.js:
var apiRoute = router.route('/api')
, bikeRoutes = require('./bikes');
apiRoute.use('/bikes', bikeRoutes);
Then in bike.js:
var express = require('express');
var router = express.Router();
var bikeRoutes = router.route('/');
bikeRoutes.get(function (req, res) {
res.send('api GET request received');
});
module.exports = bikeRoutes;
From there its easy to see that you can build many different resources and continually nest them.

How to modularize routing with Node.js Express

I'm building a web app with Express and Node and am trying to factor my routing so that I don't have hundreds of routes in the same file. This site serves different files within the projects directory, so I made a file in routes/ called projectRoutes.jsto handle the routing for project files:
var express = require('express');
module.exports = function() {
var functions = {}
functions.routeProject = function(req, res) {
res.render('pages/projects/' + req.params.string, function(err, html) {
if (err) {
res.send("Sorry! Page not found!");
} else {
res.send(html);
}
});
};
return functions;
}
Then, in my routes.js, I have this...
var projectRoutes = require("./projectRoutes");
router.get('/projects/:string', function(req, res) {
projectRoutes().routeProject(req, res);
});
Is there a better way to structure this functionality within projectRoutes.js? In other words, how can I configure projectRoutes.js so that I can write the follow line of code in index.js:
router.get('/projects/:string', projectRoutes.routeProject);
The above seems like the normal way to handle something like this, but currently the above line throws an error in Node that says the function is undefined.
Thanks for your help!
You should use the native express router, it was made to solve this exact problem! It essentially lets you create simplified nested routes in a modular way.
For each of your resources, you should separate out your routes into several modules named <yourResource>.js. Those modules would contain all of the routing code as well as any other configuration or necessary functions. Then you would attach them in index.js with:
var apiRoute = router.route('/api')
apiRoute.use('/< yourResource >', yourResourceRouter)
For example, if you had a resource bikes:
In index.js:
var apiRoute = router.route('/api')
, bikeRoutes = require('./bikes')
apiRoute.use('/bikes', bikeRoutes)
Then in bike.js:
var express = require('express')
, router = express.Router()
, bikeRoutes = router.route('/')
bikeRoutes.get(function (req, res) {
res.send('api GET request received')
});
module.exports = bikeRoutes
From there its easy to see that you can build many different resources and continually nest them.
A larger of example of connecting the routes in index.js would be:
var apiRoute = router.route('/api')
, bikeRoutes = require('./bikes')
, carRoutes = require('./cars')
, skateboardRoutes = require('./skateboards')
, rollerskateRoutes = require('./rollerskates')
// routes
apiRoute.use('/bikes', bikeRoutes)
apiRoute.use('/cars', carRoutes)
apiRoute.use('/skateboards', skateboardRoutes)
apiRoute.use('/rollerskates', rollerskateRoutes)
Each router would contain code similar to bikes.js. With this example its easy to see using express's router modularizes and makes your code base more manageable.
Another option is to use the Router object itself, instead of the Route object.
In Index.js:
//Load Routes
BikeRoutes = require('./routes/Bike.js');
CarRoutes = require('./routes/Car.js');
//Routers
var express = require('express');
var ApiRouter = express.Router();
var BikeRouter = express.Router();
var CarRouter = express.Router();
//Express App
var app = express();
//App Routes
ApiRouter.get('/Api', function(req, res){...});
ApiRouter.use('/', BikeRouter);
ApiRouter.use('/', CarRouter);
In Bike.js:
var express = require('express');
var router = express.Router();
router.get('/Bikes', function(req, res){...});
module.exports = router;
Similarly in Car.js

Run NodeJS app on nodejitsu, all i get is "cannot get /"

as part of my learning i wanted to deploy my app to nodejitsu. Its running fine on my local server, but on nodejitsu all i get is
Cannot GET /
I thought it may have something to do with the NODE_ENV set to production on the server, but i never touched this on my local server. I changed it on nodejitsu to development but still i cant get it to work.
After commenting all the code i think the problem is in my index.js which i show below:
var express = require('express');//the framework
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
//var session = require('express-session');
var methodOverride = require('method-override');
var passport = require("passport");//for authentication
var LocalStrategy = require('passport-local').Strategy;//local users for passport
var http = require('http');
var path = require('path');
var db = require('./dataBase');//to connect to the db
var userRoles = require('./routingConfig').userRoles;
var accessLevels = require('./routingConfig').accessLevels;
var debug = false;
var db = new db('inmobiliaria', 'localhost', 3306, debug);
require('./passport')(passport, db, debug)
var app = express();
app.set('port', 1337);
app.use(methodOverride());
app.use(cookieParser());
app.use(bodyParser.urlencoded({ extended: false }))
//app.use(session({ secret: 'SECRET' }));
app.use(passport.initialize());
app.use(passport.session());
app.use(function (req, res, next) {
var role = userRoles.public;//default role
var username = '';
if (req.user) {
role = req.user.role;
username = req.user.username;
}
res.cookie('user', JSON.stringify({
'username': username,
'role': role
}));
next();
});
app.use('/', express.static(path.join(__dirname + '/../Client/')));
app.use("/lib", express.static(path.join(__dirname + '/../Client/lib/')));
app.use("/ctr", express.static(path.join(__dirname + '/../Client/Controllers/')));
app.use("/media", express.static(path.join(__dirname + '/../Client/media/')));
app.use("/views", express.static(path.join(__dirname + '/../Client/Views/')));
app.use("/srv", express.static(path.join(__dirname + '/../Client/Services/')));
app.use("/dct", express.static(path.join(__dirname + '/../Client/Directives/')));
require('./routes')(app, passport, db);
//require('./emailConfiguration');
http.createServer(app).listen(process.env.PORT || app.get('port'), function (err) {
console.log("Express server listening on port " + app.get('port'));
if (err) {
throw err; // For completeness's sake.
}
});
I investigated about this variable, but im not sure it has something to do with it. This is the url http://horaciotest.jit.su/, in case you want to see it.
Is this configuration? Am i doing something that should not be done?
Thanks for taking your time.
EDIT:
i managed to reduce the error case to a few lines i think. As the guys at nodejitsu suggested, im now trying to use the module node-static to serve static files, but i cant get it to work along express:
this code works on nodejitsu and my local server (or at least doesnt show any errors)
var statik = require('node-static');
var http = require('http');
var path = require('path');
var file = new (statik.Server)(path.join(__dirname + '/../Client/'));//index.html here
http.createServer(function (req, res) {
console.log(path.join(__dirname + '/../Client/'));
file.serve(req, res);
}).listen(8080);
but as soon as i add express, i get the error i mentioned above:
var express = require('express');
var statik = require('node-static');
var http = require('http');
var path = require('path');
var app = express();
var file = new (statik.Server)(path.join(__dirname + '/../Client/'));//index.html here
http.createServer(app, function (req, res) {
console.log(path.join(__dirname + '/../Client/'));
file.serve(req, res);
}).listen(8080);
Can someone tell me why when i add the express app i get the error? it may be what i need to get this to work on nodejitsu, thanks!
I found out what the problem was, hope it helps someone:
My project structure had two folders: one was named Client, where all my html and .js from angular where.
The other folder was WebServer, where i had all my nodejs files.
In order to deploy to nodejitsu, you run a command which is jitsu deploy, this in turn runs another command: npm pack. This command creates a .tgz file with all the data in you nodejs directory excluding the node_modules file and any file that starts with .. Problem is, if you like me have files outside that folder, they wont be included.
The solutions is to move your client folder inside the nodejs one. Everything you need to sent to the server should be in side this folder.

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