My Software Versions

Node v6.9.1
NPM v4.1.2
Yarn v0.23.2

Prerequisites

Install Node
Install NPM
Install Yarn (optional)
Read React Docs
- Concentrate on concepts
- I will cover hands-on coding

Installation

Clone repository
- git clone https://github.com/tobyf93/bsm-todo.git OR
- git clone git@github.com:tobyf93/bsm-todo.git (needs SSH key set up)
cd bsm-todo
[yarn|npm install] (Install Dependencies)

Tutorial

Create Personal Branch

git checkout template
git checkout -b <yourName>

This will create you a branch new git branch that you will work on to complete this project. Ensure that you are ALWAYS working in your own branch.

src/

components/

React Components.

containers/

Also React Components. You won't understand the difference between components and containers until i introduce you to Redux.

index.html

The HTML page that our application will be injected into.

index.js

Webpack's entry point. Everything to do with our application will stem from this file.

Web Server

This project is powered by Webpack. Webpack is responsible for making builds from the source files that we create (more on this later). We will be using a Node web server called webpack-dev-server.

[yarn|npm] start [-- --port <port>] will get us off and running!

If you visit http://localhost:<port>/ you should see a really exciting web page:

Injecting React

Lets visit our entry point:

// src/index.js

import './index.html';

// Todo resources
import 'todomvc-app-css/index.css';
import 'todomvc-common/base.css';
import 'todomvc-common/base.js';

This syntax may be foreign to some of you. What this is using is the new ES6 Module system. It's telling Webpack that we want to import these assets into our project. This gives us our basic web page.

But we're not here to create a basic web page so lets get going with React! First thing we need to do is import a few more modules:

import React from 'react';
import ReactDOM from 'react-dom';

Note: import statements should be placed at the top of the file in the outer-most scope.

At this point you may be asking "Why on earth is React split into two separate modules? Why not just one?". To answer that i will explain what react-dom is for. This modules main purpose is to provide the glue between React Components and the DOM. The DOM is specific to Web Applications. When react-native came along there was no need to have web-specific code lying around in the react module as iOS/Android apps don't work with a DOM.

Ok so now that we have our modules ready to go it is time to inject something into our basic web page:

ReactDOM.render(
  <div style={{ padding: '15px', textAlign: 'center' }}>
    Hello World!
  </div>, 
  document.getElementsByClassName('todoapp')[0]
);

Here we are targeting the placeholder element that is in src/index.html:10 and injecting a JSX element into it. What we get as a result is a Hello World! example:

First React Component

Lets create a new file:

// src/containers/App.js

import React, { Component } from 'react';

class App extends Component {
  constructor(props) {
    super(props);
  }

  render() {
    return (
      <div style={{ padding: '15px', textAlign: 'center' }}>
        Hello World!
      </div>
    );
  }
}

export default App;

This is a basic React Component that does exactly what we did previously. Lets go back to our ReactDOM.render(...) call and inject our new component instead of a literal JSX element:

// src/index.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './containers/app';
import './index.html';

// Todo resources
import 'todomvc-app-css/index.css';
import 'todomvc-common/base.css';
import 'todomvc-common/base.js';

ReactDOM.render(<App />, document.getElementsByClassName('todoapp')[0]);

You won't see a different in the web page. This is a good thing! It means that we have successfully created our first React Component! The App container is going to be the root Component. All other Components will be nested within.

Footer Component

You may have noticed a Footer Component in the project. Lets go and use that in our App Component:

import React, { Component } from 'react';
import Footer from '../components/Footer';

class App extends Component {
  constructor(props) {
    super(props);
  }

  render() {
    return (
      <div>
        <Footer />
      </div>
    );
  }
}

export default App;

WOW! That looks fancy!

We have the look and feel of this Footer spot on but the functionality is missing... Next thing we need to do is to get those buttons working for us!

To do this we are going to:

Import constants
Create a state object
Create a filter method
Pass new props to Footer (show and filter)

// src/containers/App.js

import React, { Component } from 'react';
import { ALL_TODOS, ACTIVE_TODOS, COMPLETED_TODOS } from '../constants';
import Footer from '../components/Footer';

class App extends Component {
  constructor(props) {
    super(props);

    this.filter = this.filter.bind(this);
    this.state = {
      show: ALL_TODOS
    };
  }

  filter(newFilter) {
    this.setState({ show: newFilter });
  }

  render() {
    return (
      <div>
        <Footer
          show={this.state.show}
          filter={this.filter}
        />
      </div>
    );
  }
}

export default App;

Our Footer Component should look something like this to cater for the new props:

// src/components/Footer.js

import React, { Component } from 'react';
import { ALL_TODOS, ACTIVE_TODOS, COMPLETED_TODOS } from '../constants';

class Footer extends Component {
  render() {
    return (
      <footer className="footer">
        <span className="todo-count">
          <strong>99</strong> todos left
        </span>
        <ul className="filters">
          <li>
            <a
              href="#"
              className={this.props.show === ALL_TODOS ? 'selected' : ''}
              onClick={() => this.props.filter(ALL_TODOS)}
            >
              All
            </a>
          </li>
          <li>
            <a
              href="#"
              className={this.props.show === ACTIVE_TODOS ? 'selected' : ''}
              onClick={() => this.props.filter(ACTIVE_TODOS)}
            >
              Active
            </a>
          </li>
          <li>
            <a
              href="#"
              className={this.props.show === COMPLETED_TODOS ? 'selected' : ''}
              onClick={() => this.props.filter(COMPLETED_TODOS)}
            >
              Completed
            </a>
          </li>
        </ul>
        <button
          className="clear-completed"
          onClick={() => console.log('Clear completed Todos')}
        >
          Clear completed
        </button>
      </footer>
    );
  }
}

export default Footer;

Challenge

You would have noticed there are other components lying around that we haven't yet used:

Header
Todos

Lets add them into the mix:

// src/containers/App.js

...

render() {
  return (
    <div>
      <Header />
      <Todos />
      <Footer
        show={this.state.show}
        filter={this.filter}
      />
    </div>
  );
}
  
...

As a user i should be able to...

Create a Todo by typing in a label and hitting ENTER
Mark a todo as Completed by clicking the circle
See how many items are left
Filter todos by All, Active and Completed
Clear Completed Todos

BONUS:

Use local storage to preserve Todos between sessions

tobyf93 / bsm-todo