Getting Started with Mongoose and Node.js – A Sample Comments System | Dev Notes
In this post, we’re going to be creating a sample comments system using Node, Express and Mongoose. Mongoose provides an object oriented interface for using MongoDB in Node. Everything in Mongoose starts with a Schema. Each schema maps to a MongoDB collection and defines the shape of the documents within that collection. If you are not familiar with Mongoose I suggest you read the docs here .
Getting Started
For this tutorial, you will
need Express and MongoDB installed on your machine. I
covered this in a previous tutorial so refer to it in case
you don’t already have them installed.
Mongoose
To install Mongoose, open your terminal
screen and enter the following:
$ npm install mongoose
To automatically build out an application template for your application, navigate to the directory where you wish to create your application and run the following code:
mkdir MongooseExample
cd MongooseExample
express -c stylus
npm install -d
What this does:
- create the directory for your application.
- create your application template using the jade template engine and the stylus css engine.
You should now be able to run your application and see a generic Express application.
node app.js
Navigate to http://localhost:3000
Installing Dependencies
First we need to add
our dependency for Mongoose. Open
your package.json
and add the following code:
{
"name": "application-name",
"version": "0.0.1",
"private": true,
"scripts": {
"start": "node app"
},
"dependencies": {
"express": "3.1.0",
"jade": "*",
"stylus": "*",
"mongoose" : "3.2.0"
}
}
Everything should have already been there with the exception
of "mongoose" : "3.2.0"
. Once you have saved
the file run the following code to download and install the nodejs client for
mongoose:
npm install -d
The Code
db.js
Now we’re going to create a file
called db.js
to configure MongoDB and
our schema.
var mongoose = require( ‘mongoose‘ );
var Schema = mongoose.Schema;
var Comment = new Schema({
username : String,
content : String,
created : Date
});
mongoose.model( ‘Comment‘, Comment );
mongoose.connect( ‘mongodb://localhost/express-comment‘ );
Save this file in the same directory
as app.js
. The first thing we do is include
mongoose and get a reference to schema. Everything in
mongoose is derived from a schema. Next, we create our Comment schema and
compile it into a model. Last we open a connection to
our express-comment
database on our locally running
instance of MongoDB.
app.js
Open app.js and
add require( ‘./db‘ );
at the top of the
file. It should look this:
/**
* Module dependencies.
*/
require( ‘./db‘ ); //for mongoose. Require this first!!!
var express = require(‘express‘)
, routes = require(‘./routes‘)
, user = require(‘./routes/user‘)
, http = require(‘http‘)
, path = require(‘path‘);
var app = express();
app.configure(function(){
app.set(‘port‘, process.env.PORT || 3000);
app.set(‘views‘, __dirname + ‘/views‘);
app.set(‘view engine‘, ‘jade‘);
app.use(express.favicon());
app.use(express.logger(‘dev‘));
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(app.router);
app.use(require(‘stylus‘).middleware(__dirname + ‘/public‘));
app.use(express.static(path.join(__dirname, ‘public‘)));
});
app.configure(‘development‘, function(){
app.use(express.errorHandler());
});
app.get(‘/‘, routes.index);
app.get(‘/users‘, user.list);
http.createServer(app).listen(app.get(‘port‘), function(){
console.log("Express server listening on port " + app.get(‘port‘));
});
index.js
Open index.js
and add the
following code:
var mongoose = require( ‘mongoose‘ );
var Comment = mongoose.model( ‘Comment‘ );
exports.index = function ( req, res ){
Comment.find( function ( err, comments, count ){
res.render( ‘index‘, {
title : ‘Comment System with Mongoose and Node‘,
comments : comments
});
});
};
exports.create = function ( req, res ){
new Comment({
username : req.body.username,
content : req.body.comment,
created : Date.now()
}).save( function( err, comment, count ){
res.redirect( ‘/‘ );
});
};
The first thing we do is require mongoose and the Comment model before we can
use it. The index function is replaced with one that
queries the database for comments and returns them to the index
page. Comment.find
is used to pull all
comment collections. The create function saves a new
comment from form values. We’ll create the form in a
minute. First, add the following line to
app.js: app.post( ‘/create‘, routes.create
);
It should now look like this:
app.get(‘/‘, routes.index);
app.post( ‘/create‘, routes.create );
index.jade
Open index.jade
and add the form and a loop
to show the comments under the form.
extends layout
block content
h1= title
div.addCommentForm
form( method="post", action="/create")
div
div
span.label Name :
input(type="text", class="nameTxt", name="username")
div
span.label Comment :
textarea(name="comment")
div#addCommentSubmit
input(type="submit", value="Save")
br
br
#comments
- each comment in comments
div.comment
div.name= comment.username
div.created_at= comment.created
br
div.content= comment.content
hr
style.styl
You will need to pretty up the page so
open style.styl
and add the following code:
body
padding: 50px
font: 14px "Lucida Grande", Helvetica, Arial, sans-serif
a
color: #00B7FF
.addCommentForm
width 450px
input[type =text]
width 200px
margin-left 38px
textarea
width 200px
margin-left 10px
input[type =button], input[type =submit]
clear both
margin-left 85px
display block
.label
text-align right !important
display block
float left
#comments
.name
float left
.created_at
float right
.content
clear both
Now re-run the application and you should be able to add comments which will display under the form. Navigate to localhost:3000 and make sure you have MongoDB up and running.
node app.js
Download the source code at https://github.com/ijason/NodeJS-Mongoose
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