Using MongoDB with express

MongoDB

https://www.mongodb.com/download-center?jmp=nav#community

Create data directory

This is where all your MongoDB data will be stored.

Mac
- mkdir /data/db
- sudo chmod 0755 /data/db
- sudo chown $USER /data/db
Windows
- md /data/db

Starting the mongo service and connecting to it

Now we will start a MongoDB instance locally.

mongod in a terminal
open new terminal and run mongo
type help to see what you can do

configs

Next, we will create an environment variable file. In this file, we will identify what port we want to be opened up for the server, and what the address of our MongoDB will be. Normally, you will not want to place this file in a version control repository. These should all be secrets, that are only know in the environment where they are run.

create file .env
Add the following:

PORT=XXXX
MONGODB=localhost:XXXXX/DB

Connect Mongo and the Server using mongoose

First, we will install some dependencies.

npm i -S mongoose dotenv bodyparser
- Mongoose: This will help us connect to our MongoDB, and create objects that resemble the data in our database.
- dotenv: this allows us to use the environment variables store in the .env file
- bodyparser: This will allow us to parse data more easily when users make requests to our server.
Add the following to index.js (the previous code is represented as comments)

require('dotenv').config();
/*other requires*/
var mongoose = require('mongoose');
var bodyParser = require('body-parser');
/* express, router, etc */
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: false}));

var connection = mongoose.connect(process.env.MONGODB).connection;
connection.on('error', console.error.bind(console, 'connection error'));
connection.once('open', function() {
  console.log('MongoDB is now connected');
});

app.listen(process.env.PORT, function() {
    console.log('Your server is running on port ' + process.env.PORT)
});

module.exports = app;

Run it

Run node server.js at the root of the project again, and check it out at localhost:PORT where PORT is the port you saved in your .env file. You should also now see an additonal log in your terminal letting you know your MongoDB instance is now running.

Create message model

Now we will create an object that will represent a message in our database. We will represent the actual message, the room it was sent from, and who the user was.

mkdir app/models
create file Message.js
add the following:

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var messageSchema = new Schema({
  message: {type: String, required: true},
  room: {type: String, required: true},
  user: {type: String, required: true}
});

module.exports = mongoose.model('Message', messageSchema);

Create an add message route

Now edit the router again, adding a new route, a POST route that will create a new message in our data base using the save function provided by mongoose.

open routes/index.js
add the following

/* previous requires */
var Message = require('../models/Message');
/* get root route */
router.post('/messages', function(req, res, next) {
  Message(req.body).save(function(err) {
    if (err) {
      res.send(err);
    }
    res.send('Message saved');
  })
});

module.exports = router;

Test it out

Download postman if you haven't already.
Change the request type dropdown to POST(it should initially say GET) *
set the address to localhost:PORT/messages
Navigate to the body tab (below the address bar)
select the raw radio button
change the data type dropdown to JSON (Originally, it should say Text)

add the following json data to the text input box

{
"message": "Hello",
"user": "jeremy",
"room": "Hello, World"
}

Finally, hit the blue send button

Check in mongo

open your mongo shell again
type use DB
type db.messages.find()

Get messages

open routes/index.js again
add the following (also remove our old /message route)

/* previous routes (remove the get('/message' route))*/
router.get('/messages', function(req, res, next) {
  Message.find(function(err, messages) {
    if (err) {
      res.send(err);
    }
    res.send(messages);
  })
});

Check it out

node index.js at the project root
go to localhost:PORT/messages
You should now be able to see the json data for the message we just sent.

Last thing... Let's add a logger

npm i -S morgan
add the following to index.js

var logger = require('morgan');
/*app stuff */
app.use(logger('dev'));

Now, send another post request, and you will be able to see better output for what exactly is happening in our server.

Using MongoDB