il y a 7 ans · 89c1875ec8
--- a/hw3/task1/.gitignore
+++ b/hw3/task1/.gitignore
@@ -0,0 +1,21 @@
 
				+# See https://help.github.com/ignore-files/ for more about ignoring files.
			
 
				+
			
 
				+# dependencies
			
 
				+/node_modules
			
 
				+
			
 
				+# testing
			
 
				+/coverage
			
 
				+
			
 
				+# production
			
 
				+/build
			
 
				+
			
 
				+# misc
			
 
				+.DS_Store
			
 
				+.env.local
			
 
				+.env.development.local
			
 
				+.env.test.local
			
 
				+.env.production.local
			
 
				+
			
 
				+npm-debug.log*
			
 
				+yarn-debug.log*
			
 
				+yarn-error.log*
			
--- a/hw3/task1/README.md
+++ b/hw3/task1/README.md
--- a/hw3/task1/package-lock.json
+++ b/hw3/task1/package-lock.json
--- a/hw3/task1/package.json
+++ b/hw3/task1/package.json
@@ -0,0 +1,16 @@
 
				+{
			
 
				+  "name": "task1",
			
 
				+  "version": "0.1.0",
			
 
				+  "private": true,
			
 
				+  "dependencies": {
			
 
				+    "react": "^16.2.0",
			
 
				+    "react-dom": "^16.2.0",
			
 
				+    "react-scripts": "1.0.17"
			
 
				+  },
			
 
				+  "scripts": {
			
 
				+    "start": "react-scripts start",
			
 
				+    "build": "react-scripts build",
			
 
				+    "test": "react-scripts test --env=jsdom",
			
 
				+    "eject": "react-scripts eject"
			
 
				+  }
			
 
				+}
			
--- a/hw3/task1/public/favicon.ico
+++ b/hw3/task1/public/favicon.ico
--- a/hw3/task1/public/index.html
+++ b/hw3/task1/public/index.html
@@ -0,0 +1,40 @@
 
				+<!DOCTYPE html>
			
 
				+<html lang="en">
			
 
				+  <head>
			
 
				+    <meta charset="utf-8">
			
 
				+    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
			
 
				+    <meta name="theme-color" content="#000000">
			
 
				+    <!--
			
 
				+      manifest.json provides metadata used when your web app is added to the
			
 
				+      homescreen on Android. See https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/
			
 
				+    -->
			
 
				+    <link rel="manifest" href="%PUBLIC_URL%/manifest.json">
			
 
				+    <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
			
 
				+    <!--
			
 
				+      Notice the use of %PUBLIC_URL% in the tags above.
			
 
				+      It will be replaced with the URL of the `public` folder during the build.
			
 
				+      Only files inside the `public` folder can be referenced from the HTML.
			
 
				+
			
 
				+      Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
			
 
				+      work correctly both with client-side routing and a non-root public URL.
			
 
				+      Learn how to configure a non-root public URL by running `npm run build`.
			
 
				+    -->
			
 
				+    <title>React App</title>
			
 
				+  </head>
			
 
				+  <body>
			
 
				+    <noscript>
			
 
				+      You need to enable JavaScript to run this app.
			
 
				+    </noscript>
			
 
				+    <div id="root"></div>
			
 
				+    <!--
			
 
				+      This HTML file is a template.
			
 
				+      If you open it directly in the browser, you will see an empty page.
			
 
				+
			
 
				+      You can add webfonts, meta tags, or analytics to this file.
			
 
				+      The build step will place the bundled scripts into the <body> tag.
			
 
				+
			
 
				+      To begin the development, run `npm start` or `yarn start`.
			
 
				+      To create a production bundle, use `npm run build` or `yarn build`.
			
 
				+    -->
			
 
				+  </body>
			
 
				+</html>
			
--- a/hw3/task1/public/manifest.json
+++ b/hw3/task1/public/manifest.json
@@ -0,0 +1,15 @@
 
				+{
			
 
				+  "short_name": "React App",
			
 
				+  "name": "Create React App Sample",
			
 
				+  "icons": [
			
 
				+    {
			
 
				+      "src": "favicon.ico",
			
 
				+      "sizes": "64x64 32x32 24x24 16x16",
			
 
				+      "type": "image/x-icon"
			
 
				+    }
			
 
				+  ],
			
 
				+  "start_url": "./index.html",
			
 
				+  "display": "standalone",
			
 
				+  "theme_color": "#000000",
			
 
				+  "background_color": "#ffffff"
			
 
				+}
			
--- a/hw3/task1/src/App.js
+++ b/hw3/task1/src/App.js
@@ -0,0 +1,29 @@
 
				+import React, { Component } from 'react';
			
 
				+import './css/app.css';
			
 
				+
			
 
				+class App extends Component {
			
 
				+  constructor(props){
			
 
				+    super(props);
			
 
				+    this.state = {
			
 
				+      count: 0,
			
 
				+    }
			
 
				+  }
			
 
				+  render() {
			
 
				+    return (
			
 
				+      <div>
			
 
				+        <button onClick={this.decreaseCount}>-</button>
			
 
				+        {this.state.count}
			
 
				+        <button onClick={this.increaseCount}>+</button>
			
 
				+      </div>
			
 
				+    );
			
 
				+  }
			
 
				+  //custom methods
			
 
				+  decreaseCount = ()=>{
			
 
				+    this.setState((prevState,props)=>({count: --prevState.count}))
			
 
				+  }
			
 
				+  increaseCount = ()=>{
			
 
				+    this.setState((prevState,props)=>({count: ++prevState.count}))
			
 
				+  }
			
 
				+}
			
 
				+
			
 
				+export default App;
			
--- a/hw3/task1/src/App.test.js
+++ b/hw3/task1/src/App.test.js
@@ -0,0 +1,8 @@
 
				+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);
			
 
				+});
			
--- a/hw3/task1/src/css/app.css
+++ b/hw3/task1/src/css/app.css
@@ -0,0 +1,5 @@
 
				+body * {
			
 
				+  box-sizing: border-box;
			
 
				+  margin: 5px;
			
 
				+  font-size: 20px;
			
 
				+}
			
--- a/hw3/task1/src/css/index.css
+++ b/hw3/task1/src/css/index.css
@@ -0,0 +1,5 @@
 
				+body {
			
 
				+  margin: 0;
			
 
				+  padding: 0;
			
 
				+  font-family: sans-serif;
			
 
				+}
			
--- a/hw3/task1/src/index.js
+++ b/hw3/task1/src/index.js
@@ -0,0 +1,8 @@
 
				+import React from 'react';
			
 
				+import ReactDOM from 'react-dom';
			
 
				+import './css/index.css';
			
 
				+import App from './App';
			
 
				+import registerServiceWorker from './registerServiceWorker';
			
 
				+
			
 
				+ReactDOM.render(<App />, document.getElementById('root'));
			
 
				+registerServiceWorker();
			
--- a/hw3/task1/src/registerServiceWorker.js
+++ b/hw3/task1/src/registerServiceWorker.js
@@ -0,0 +1,108 @@
 
				+// 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);
			
 
				+      } 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();
			
 
				+    });
			
 
				+  }
			
 
				+}
			
--- a/hw3/task2/.gitignore
+++ b/hw3/task2/.gitignore
@@ -0,0 +1,21 @@
 
				+# See https://help.github.com/ignore-files/ for more about ignoring files.
			
 
				+
			
 
				+# dependencies
			
 
				+/node_modules
			
 
				+
			
 
				+# testing
			
 
				+/coverage
			
 
				+
			
 
				+# production
			
 
				+/build
			
 
				+
			
 
				+# misc
			
 
				+.DS_Store
			
 
				+.env.local
			
 
				+.env.development.local
			
 
				+.env.test.local
			
 
				+.env.production.local
			
 
				+
			
 
				+npm-debug.log*
			
 
				+yarn-debug.log*
			
 
				+yarn-error.log*
			
--- a/hw3/task2/README.md
+++ b/hw3/task2/README.md
--- a/hw3/task2/package-lock.json
+++ b/hw3/task2/package-lock.json
--- a/hw3/task2/package.json
+++ b/hw3/task2/package.json
@@ -0,0 +1,16 @@
 
				+{
			
 
				+  "name": "task2",
			
 
				+  "version": "0.1.0",
			
 
				+  "private": true,
			
 
				+  "dependencies": {
			
 
				+    "react": "^16.2.0",
			
 
				+    "react-dom": "^16.2.0",
			
 
				+    "react-scripts": "1.0.17"
			
 
				+  },
			
 
				+  "scripts": {
			
 
				+    "start": "react-scripts start",
			
 
				+    "build": "react-scripts build",
			
 
				+    "test": "react-scripts test --env=jsdom",
			
 
				+    "eject": "react-scripts eject"
			
 
				+  }
			
 
				+}
			
--- a/hw3/task2/public/favicon.ico
+++ b/hw3/task2/public/favicon.ico
--- a/hw3/task2/public/index.html
+++ b/hw3/task2/public/index.html
@@ -0,0 +1,40 @@
 
				+<!DOCTYPE html>
			
 
				+<html lang="en">
			
 
				+  <head>
			
 
				+    <meta charset="utf-8">
			
 
				+    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
			
 
				+    <meta name="theme-color" content="#000000">
			
 
				+    <!--
			
 
				+      manifest.json provides metadata used when your web app is added to the
			
 
				+      homescreen on Android. See https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/
			
 
				+    -->
			
 
				+    <link rel="manifest" href="%PUBLIC_URL%/manifest.json">
			
 
				+    <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
			
 
				+    <!--
			
 
				+      Notice the use of %PUBLIC_URL% in the tags above.
			
 
				+      It will be replaced with the URL of the `public` folder during the build.
			
 
				+      Only files inside the `public` folder can be referenced from the HTML.
			
 
				+
			
 
				+      Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
			
 
				+      work correctly both with client-side routing and a non-root public URL.
			
 
				+      Learn how to configure a non-root public URL by running `npm run build`.
			
 
				+    -->
			
 
				+    <title>React App</title>
			
 
				+  </head>
			
 
				+  <body>
			
 
				+    <noscript>
			
 
				+      You need to enable JavaScript to run this app.
			
 
				+    </noscript>
			
 
				+    <div id="root"></div>
			
 
				+    <!--
			
 
				+      This HTML file is a template.
			
 
				+      If you open it directly in the browser, you will see an empty page.
			
 
				+
			
 
				+      You can add webfonts, meta tags, or analytics to this file.
			
 
				+      The build step will place the bundled scripts into the <body> tag.
			
 
				+
			
 
				+      To begin the development, run `npm start` or `yarn start`.
			
 
				+      To create a production bundle, use `npm run build` or `yarn build`.
			
 
				+    -->
			
 
				+  </body>
			
 
				+</html>
			
--- a/hw3/task2/public/manifest.json
+++ b/hw3/task2/public/manifest.json
@@ -0,0 +1,15 @@
 
				+{
			
 
				+  "short_name": "React App",
			
 
				+  "name": "Create React App Sample",
			
 
				+  "icons": [
			
 
				+    {
			
 
				+      "src": "favicon.ico",
			
 
				+      "sizes": "64x64 32x32 24x24 16x16",
			
 
				+      "type": "image/x-icon"
			
 
				+    }
			
 
				+  ],
			
 
				+  "start_url": "./index.html",
			
 
				+  "display": "standalone",
			
 
				+  "theme_color": "#000000",
			
 
				+  "background_color": "#ffffff"
			
 
				+}
			
--- a/hw3/task2/src/App.js
+++ b/hw3/task2/src/App.js
@@ -0,0 +1,35 @@
 
				+import React, { Component } from 'react';
			
 
				+import './css/App.css';
			
 
				+
			
 
				+class App extends Component {
			
 
				+  constructor(props){
			
 
				+    super(props);
			
 
				+    this.state = {
			
 
				+      textStyle: {
			
 
				+        color: null,
			
 
				+      }
			
 
				+    }
			
 
				+  }
			
 
				+  render() {
			
 
				+    return (
			
 
				+      <div>
			
 
				+        <div style={this.state.textStyle}>Text</div>
			
 
				+        <button onClick={this.red}>Red</button>
			
 
				+        <button onClick={this.blue}>Blue</button>
			
 
				+        <button onClick={this.reset}>Reset</button>
			
 
				+      </div>
			
 
				+    );
			
 
				+  }
			
 
				+  //custom methods
			
 
				+  red = ()=>{
			
 
				+    this.setState({textStyle: {color: 'red'}});
			
 
				+  }
			
 
				+  blue = ()=>{
			
 
				+    this.setState({textStyle: {color: 'blue'}});
			
 
				+  }
			
 
				+  reset = ()=>{
			
 
				+    this.setState({textStyle: {color: null}});
			
 
				+  }
			
 
				+}
			
 
				+
			
 
				+export default App;
			
--- a/hw3/task2/src/App.test.js
+++ b/hw3/task2/src/App.test.js
@@ -0,0 +1,8 @@
 
				+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);
			
 
				+});
			
--- a/hw3/task2/src/css/App.css
+++ b/hw3/task2/src/css/App.css
@@ -0,0 +1,7 @@
 
				+.textRed {
			
 
				+  color: 'red';
			
 
				+}
			
 
				+
			
 
				+.textGreen {
			
 
				+  color: 'green';
			
 
				+}
			
--- a/hw3/task2/src/css/index.css
+++ b/hw3/task2/src/css/index.css
@@ -0,0 +1,12 @@
 
				+body {
			
 
				+  margin: 0;
			
 
				+  padding: 0;
			
 
				+
			
 
				+}
			
 
				+
			
 
				+body * {
			
 
				+  box-sizing: border-box;
			
 
				+  margin: 5px;
			
 
				+  font-family: 'Open Sans', sans-serif;
			
 
				+  font-size: 20px;
			
 
				+}
			
--- a/hw3/task2/src/index.js
+++ b/hw3/task2/src/index.js
@@ -0,0 +1,8 @@
 
				+import React from 'react';
			
 
				+import ReactDOM from 'react-dom';
			
 
				+import './css/index.css';
			
 
				+import App from './App';
			
 
				+import registerServiceWorker from './registerServiceWorker';
			
 
				+
			
 
				+ReactDOM.render(<App />, document.getElementById('root'));
			
 
				+registerServiceWorker();
			
--- a/hw3/task2/src/registerServiceWorker.js
+++ b/hw3/task2/src/registerServiceWorker.js
@@ -0,0 +1,108 @@
 
				+// 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);
			
 
				+      } 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();
			
 
				+    });
			
 
				+  }
			
 
				+}