Simple Todo app with Node.js and Express : Mijo Kristo

Simple Todo app with Node.js and Express

In this quick tutorial we will be creating a Todo app without Database. The application will be very basic but will have all features as a “real todo app” like:

Add and complete task on single page (routing)
We will use Express
Minimal CSS styling

Setup

Create an empty directory called TodoApp
Open console and run npm init
Fill out the required information
Create a file named index.js

To get our server up and running we need to use Express.js. Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.

Now we will install Express.js

npm install express --save

In index.js we need to add the following code:

var express = require('express');
var app = express()
app.get('/', function (req, res) {
  res.send('Hello World!');
});
app.listen(8080, function () {
  console.log('Running on port 8080!')
});

Now we can test our server by running:

node index.js

If you open your browser and visit: localhost:8080 and you should see Hello World!
The next part is to set our view. I will use EJS (Embedded JavaScript templating). EJS is a simple templating language that lets you generate HTML markup with plain JavaScript. No religiousness about how to organize things. No reinvention of iteration and control-flow. It’s just plain JavaScript.

Install EJS by running:

npm install ejs --save

Then in our index.js we need to add this line of code:

app.set('view engine', 'ejs');

EJS is accessed by default in the views directory. We need to create that folder. Within that folder we will add file index.ejs.
Our file looks like this.

<html>
  <head>
    <title> Todo app  </title>
    <link href="/styles.css" rel="stylesheet">
  </head>
<body>
  <div class="container">
     <h2> Simple Todo app </h2>
<form action ="/addtask" method="POST">
       <input type="text" name="newtask" placeholder="add new task">        <button> Add Task </button>
    <h2> Added Task </h2>
<button formaction="/removetask" type="submit"> Remove </button>
</form>
    <h2> Completed task </h2>
</div>
</body>
</html>

Next we need to replace our app.get in index.jsin order to send the equivalent HTML to the client.

app.get('/', function(req, res){
   res.render('index');
});

Now, if you run node index.js you shloud see content of index.ejs.

Let’s add our task.

Curently our form is submitting a post request to /addtask so we need to modifed route in our index.js file.

app.post('/addtask', function (req, res) {
   res.render('index')
});

The next step is to use Express Middleware. I recently published a post about Express Middleware. Middlewares are functions that have access to the reqand resbodies in order to preform more advanced tasks. We need to use body-parsermiddleware. It allows us to make use of the key-value pairs stored on the req-body object.

So let’s install it.

npm install body-parser --save

Once installed, we can require it:

var bodyParser = require("body-parser");
app.use(bodyParser.urlencoded({ extended: true }));

Let’s update our index.js to display a list of all the newtask added by the user.

var task = ["buy milk", "learn javascript", "learn express"];

app.post('/addtask', function (req, res) {
    var newTask = req.body.newtask;
    task.push(newTask);
    res.redirect("/");
});
app.get("/", function(req, res) {
    res.render(‘index’, { task: task, complete: complete});
});

The index.ejs file:

<h2> Added Task </h2>
   <% for( var i = 0; i < task.length; i++){ %>
<li><input type="checkbox" name="check" value="<%= task[i] %>" /> <%= task[i] %> </li>
<% } %>

You can test the app by adding the todo item.

Now we need to add the delete button.

<button formaction="/removetask" type="submit"> Remove </button>

In our index.js file:

var complete = ["finish learning nodejs"];
app.post("/removetask", function(req, res) {
     var completeTask = req.body.check;
if (typeof completeTask === "string") {
     complete.push(completeTask);
  task.splice(task.indexOf(completeTask), 1);
  } else if (typeof completeTask === "object") {
    for (var i = 0; i < completeTask.length; i++) {     complete.push(completeTask[i]);
    task.splice(task.indexOf(completeTask[i]), 1);
}
}
   res.redirect("/");
});

And finally, index.ejs

<h2> Completed task </h2>
    <% for(var i = 0; i < complete.length; i++){ %>
      <li><input type="checkbox" checked><%= complete[i] %> </li>
<% } %>

Last but not least we will add some CSS to our app.

* {
    font-family: "lato", sans-serif;
    font-weight: bold;
}

body {
    background: rgb(245, 245, 245);
    color: #555555;
    margin-top: 20px;
}

.container {
    display: block;
    width: 350px;
    margin: 0 auto;
}

ul {
    margin: 0;
    padding: 0;
}

We need to add another folder called public and inside of that folder we need to create style.css.
Express won’ t allow access to this file by default, so we need to expose it with the following line of code in our index.js file like this:

app.use(express.static("public"));

Thank you for reading.

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