first one

App.css

@@ -0,0 +1,28 @@
+.App {
+  text-align: center;
+}
+
+.App-logo {
+  animation: App-logo-spin infinite 20s linear;
+  height: 80px;
+}
+
+.App-header {
+  background-color: #222;
+  height: 150px;
+  padding: 20px;
+  color: white;
+}
+
+.App-title {
+  font-size: 1.5em;
+}
+
+.App-intro {
+  font-size: large;
+}
+
+@keyframes App-logo-spin {
+  from { transform: rotate(0deg); }
+  to { transform: rotate(360deg); }
+}

App.js

@@ -0,0 +1,154 @@
+import React, { Component } from 'react';
+import logo from './logo.svg';
+import './App.css';
+
+import { connect, Provider } from 'react-redux';
+import { createStore, combineReducers } from 'redux';
+
+
+let todoList = [
+    {
+        title: 'todo one',
+        text:  'todo one text',
+        timestamp: (new Date()).getTime()
+    },
+    {
+        title: 'todo two',
+        text:  'todo two text',
+        timestamp: (new Date()).getTime()
+    },
+    {
+        title: 'todo three',
+        text:  'todo three text',
+        timestamp: (new Date()).getTime()
+    }
+];
+
+
+function todoReducer(state, action){
+    if (typeof state === 'undefined'){
+        return {items: JSON.parse(localStorage.todo)};
+    }
+    if (action.type == 'NEW_TODO'){
+        console.log(state);
+        return {items: [...state.items, {title: action.title, text: action.text, timestamp: (new Date()).getTime()}]}
+    }
+    if (action.type == 'DELETE_TODO'){
+        let items = [];
+        for (let i=0;i<state.items.length;i++){
+            if (state.items[i].timestamp != action.timestamp){
+                items.push(state.items[i]);
+            }
+        }
+        return {items};
+    }
+}
+
+const reducers = combineReducers({
+    todo: todoReducer,
+})
+
+
+var store = createStore(reducers)
+
+store.subscribe(() => {
+    let state = store.getState();
+    localStorage.todo = JSON.stringify(state.todo.items);
+})
+
+
+
+
+class ToDoItem extends Component {
+    constructor(props){
+        super(props);
+        this.delete = this.delete.bind(this);
+    }
+    delete() {
+        store.dispatch({type: "DELETE_TODO", timestamp: this.props.item.timestamp})
+    }
+
+    render() {
+        return (
+            <div>
+                <h3> { this.props.item.title } </h3>
+                <p> { this.props.item.text }</p>
+                <span> { (new Date(this.props.item.timestamp)).toLocaleString() } {this.props.item.timestamp} </span>
+                <button onClick={this.delete} >x</button>
+            </div>
+        );
+    }
+}
+
+class ToDoForm extends Component {
+    constructor (props) {
+        super(props);
+        this.save = this.save.bind(this);
+        this.state = {valid: true};
+    }
+
+    validator(){
+        return this.title.value && this.text.value;
+    }
+
+    save() {
+        let valid = this.validator();
+        this.setState({valid})
+        if (valid){
+            store.dispatch({type: 'NEW_TODO',
+                            title:  this.title.value,
+                            text:   this.text.value})
+            this.title.value = '';
+            this.text.value  = '';
+        }
+    }
+
+    
+    render (){
+        let style = {
+            backgroundColor: this.state.valid ? '' : 'red'
+        }
+        return (
+            <div>
+                <input style={style} placeholder='title' ref={ c => this.title = c}/>
+                <input style={style} placeholder='text' ref={ c => this.text = c} />
+                <button onClick = { this.save } >Save</button>
+            </div>
+        );
+    }
+}
+
+class ToDoList extends Component {
+    render (){
+        return (
+            <div> <h1>TODO LIST</h1>
+                <ToDoForm />
+                { this.props.items.map( (item, index) => <ToDoItem key={index} item={item} />) }
+            </div>
+        );
+    }
+}
+
+const mapStateToProps = function(store){
+    return {
+        items: store.todo.items
+    };
+}
+
+ToDoList = connect(mapStateToProps)(ToDoList);
+
+
+
+class App extends Component {
+  render() {
+    return (
+      <div className="App">
+        <Provider store={store} >
+            <ToDoList />
+        </Provider>
+      </div>
+    );
+  }
+}
+
+export default App;

App.test.js

@@ -0,0 +1,9 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+import App from './App';
+
+it('renders without crashing', () => {
+  const div = document.createElement('div');
+  ReactDOM.render(<App />, div);
+  ReactDOM.unmountComponentAtNode(div);
+});

index.css

@@ -0,0 +1,5 @@
+body {
+  margin: 0;
+  padding: 0;
+  font-family: sans-serif;
+}

index.js

@@ -0,0 +1,8 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+import './index.css';
+import App from './App';
+import registerServiceWorker from './registerServiceWorker';
+
+ReactDOM.render(<App />, document.getElementById('root'));
+registerServiceWorker();

registerServiceWorker.js

@@ -0,0 +1,117 @@
+// In production, we register a service worker to serve assets from local cache.
+
+// This lets the app load faster on subsequent visits in production, and gives
+// it offline capabilities. However, it also means that developers (and users)
+// will only see deployed updates on the "N+1" visit to a page, since previously
+// cached resources are updated in the background.
+
+// To learn more about the benefits of this model, read https://goo.gl/KwvDNy.
+// This link also includes instructions on opting out of this behavior.
+
+const isLocalhost = Boolean(
+  window.location.hostname === 'localhost' ||
+    // [::1] is the IPv6 localhost address.
+    window.location.hostname === '[::1]' ||
+    // 127.0.0.1/8 is considered localhost for IPv4.
+    window.location.hostname.match(
+      /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
+    )
+);
+
+export default function register() {
+  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
+    // The URL constructor is available in all browsers that support SW.
+    const publicUrl = new URL(process.env.PUBLIC_URL, window.location);
+    if (publicUrl.origin !== window.location.origin) {
+      // Our service worker won't work if PUBLIC_URL is on a different origin
+      // from what our page is served on. This might happen if a CDN is used to
+      // serve assets; see https://github.com/facebookincubator/create-react-app/issues/2374
+      return;
+    }
+
+    window.addEventListener('load', () => {
+      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
+
+      if (isLocalhost) {
+        // This is running on localhost. Lets check if a service worker still exists or not.
+        checkValidServiceWorker(swUrl);
+
+        // Add some additional logging to localhost, pointing developers to the
+        // service worker/PWA documentation.
+        navigator.serviceWorker.ready.then(() => {
+          console.log(
+            'This web app is being served cache-first by a service ' +
+              'worker. To learn more, visit https://goo.gl/SC7cgQ'
+          );
+        });
+      } else {
+        // Is not local host. Just register service worker
+        registerValidSW(swUrl);
+      }
+    });
+  }
+}
+
+function registerValidSW(swUrl) {
+  navigator.serviceWorker
+    .register(swUrl)
+    .then(registration => {
+      registration.onupdatefound = () => {
+        const installingWorker = registration.installing;
+        installingWorker.onstatechange = () => {
+          if (installingWorker.state === 'installed') {
+            if (navigator.serviceWorker.controller) {
+              // At this point, the old content will have been purged and
+              // the fresh content will have been added to the cache.
+              // It's the perfect time to display a "New content is
+              // available; please refresh." message in your web app.
+              console.log('New content is available; please refresh.');
+            } else {
+              // At this point, everything has been precached.
+              // It's the perfect time to display a
+              // "Content is cached for offline use." message.
+              console.log('Content is cached for offline use.');
+            }
+          }
+        };
+      };
+    })
+    .catch(error => {
+      console.error('Error during service worker registration:', error);
+    });
+}
+
+function checkValidServiceWorker(swUrl) {
+  // Check if the service worker can be found. If it can't reload the page.
+  fetch(swUrl)
+    .then(response => {
+      // Ensure service worker exists, and that we really are getting a JS file.
+      if (
+        response.status === 404 ||
+        response.headers.get('content-type').indexOf('javascript') === -1
+      ) {
+        // No service worker found. Probably a different app. Reload the page.
+        navigator.serviceWorker.ready.then(registration => {
+          registration.unregister().then(() => {
+            window.location.reload();
+          });
+        });
+      } else {
+        // Service worker found. Proceed as normal.
+        registerValidSW(swUrl);
+      }
+    })
+    .catch(() => {
+      console.log(
+        'No internet connection found. App is running in offline mode.'
+      );
+    });
+}
+
+export function unregister() {
+  if ('serviceWorker' in navigator) {
+    navigator.serviceWorker.ready.then(registration => {
+      registration.unregister();
+    });
+  }
+}