init

rwieruch · rwieruch · commit 0fcb65f8f97f · 2018-10-30T08:17:11.000+08:00
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,21 @@
+# See https://help.github.com/articles/ignoring-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*
diff --git a/.prettierrc b/.prettierrc
@@ -0,0 +1,7 @@
+
+{
+  "semi": true,
+  "trailingComma": "all",
+  "singleQuote": true,
+  "printWidth": 70
+}
diff --git a/README.md b/README.md
@@ -0,0 +1,13 @@
+# react-hooks-introduction
+
+[![Build Status](https://travis-ci.org/the-road-to-learn-react/react-hooks-introduction.svg?branch=master)](https://travis-ci.org/the-road-to-learn-react/react-hooks-introduction) [![Slack](https://slack-the-road-to-learn-react.wieruch.com/badge.svg)](https://slack-the-road-to-learn-react.wieruch.com/)
+
+Showcasing popular React Hooks in function components such as useState, useEffect and custom hooks. [Read more about it.](https://www.robinwieruch.de/react-hooks/)
+
+## Installation
+
+* `git clone git@github.com:the-road-to-learn-react/react-hooks-introduction.git`
+* cd react-hooks-introduction
+* npm install
+* npm start
+* visit `http://localhost:3000`
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -0,0 +1,26 @@
+{
+  "name": "react-hooks-introduction",
+  "version": "0.1.0",
+  "private": true,
+  "dependencies": {
+    "axios": "^0.18.0",
+    "react": "^16.7.0-alpha.0",
+    "react-dom": "^16.7.0-alpha.0",
+    "react-scripts": "2.0.5"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build",
+    "test": "react-scripts test",
+    "eject": "react-scripts eject"
+  },
+  "eslintConfig": {
+    "extends": "react-app"
+  },
+  "browserslist": [
+    ">0.2%",
+    "not dead",
+    "not ie <= 11",
+    "not op_mini all"
+  ]
+}
diff --git a/public/favicon.ico b/public/favicon.ico
diff --git a/public/index.html b/public/index.html
@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
+    <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/web-app-manifest/
+    -->
+    <link rel="manifest" href="%PUBLIC_URL%/manifest.json">
+    <!--
+      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>
diff --git a/public/manifest.json b/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": ".",
+  "display": "standalone",
+  "theme_color": "#000000",
+  "background_color": "#ffffff"
+}
diff --git a/src/customHook-example/index.js b/src/customHook-example/index.js
@@ -0,0 +1,37 @@
+import React, { useState, useEffect } from 'react';
+
+function useOffline() {
+  const [isOffline, setIsOffline] = useState(false);
+
+  function onOffline() {
+    setIsOffline(true);
+  }
+
+  function onOnline() {
+    setIsOffline(false);
+  }
+
+  useEffect(() => {
+    window.addEventListener('offline', onOffline);
+    window.addEventListener('online', onOnline);
+
+    return () => {
+      window.removeEventListener('offline', onOffline);
+      window.removeEventListener('online', onOnline);
+    };
+  }, []);
+
+  return isOffline;
+}
+
+function App() {
+  const isOffline = useOffline();
+
+  if (isOffline) {
+    return <div>Sorry, you are offline ...</div>;
+  }
+
+  return <div>You are online!</div>;
+}
+
+export default App;
diff --git a/src/customHook-example/test.js b/src/customHook-example/test.js
@@ -0,0 +1,9 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+import App from './';
+
+it('renders without crashing', () => {
+  const div = document.createElement('div');
+  ReactDOM.render(<App />, div);
+  ReactDOM.unmountComponentAtNode(div);
+});
diff --git a/src/index.js b/src/index.js
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+import React from 'react';
+import ReactDOM from 'react-dom';
+
+// import App from './useState-example';
+// import App from './useEffect-example';
+// import App from './customHook-example';
+import App from './useDataApiHook-example';
+
+import * as serviceWorker from './serviceWorker';
+
+ReactDOM.render(<App />, document.getElementById('root'));
+
+// If you want your app to work offline and load faster, you can change
+// unregister() to register() below. Note this comes with some pitfalls.
+// Learn more about service workers: http://bit.ly/CRA-PWA
+serviceWorker.unregister();
diff --git a/src/serviceWorker.js b/src/serviceWorker.js
@@ -0,0 +1,131 @@
+// This optional code is used to register a service worker.
+// register() is not called by default.
+
+// 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 subsequent visits to a page, after all the
+// existing tabs open on the page have been closed, since previously cached
+// resources are updated in the background.
+
+// To learn more about the benefits of this model and instructions on how to
+// opt-in, read http://bit.ly/CRA-PWA.
+
+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}$/
+    )
+);
+
+export function register(config) {
+  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
+    // The URL constructor is available in all browsers that support SW.
+    const publicUrl = new URL(process.env.PUBLIC_URL, window.location);
+    if (publicUrl.origin !== window.location.origin) {
+      // Our service worker won't work if PUBLIC_URL is on a different origin
+      // from what our page is served on. This might happen if a CDN is used to
+      // serve assets; see https://github.com/facebook/create-react-app/issues/2374
+      return;
+    }
+
+    window.addEventListener('load', () => {
+      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
+
+      if (isLocalhost) {
+        // This is running on localhost. Let's check if a service worker still exists or not.
+        checkValidServiceWorker(swUrl, config);
+
+        // 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 http://bit.ly/CRA-PWA'
+          );
+        });
+      } else {
+        // Is not localhost. Just register service worker
+        registerValidSW(swUrl, config);
+      }
+    });
+  }
+}
+
+function registerValidSW(swUrl, config) {
+  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 updated precached content has been fetched,
+              // but the previous service worker will still serve the older
+              // content until all client tabs are closed.
+              console.log(
+                'New content is available and will be used when all ' +
+                  'tabs for this page are closed. See http://bit.ly/CRA-PWA.'
+              );
+
+              // Execute callback
+              if (config && config.onUpdate) {
+                config.onUpdate(registration);
+              }
+            } 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.');
+
+              // Execute callback
+              if (config && config.onSuccess) {
+                config.onSuccess(registration);
+              }
+            }
+          }
+        };
+      };
+    })
+    .catch(error => {
+      console.error('Error during service worker registration:', error);
+    });
+}
+
+function checkValidServiceWorker(swUrl, config) {
+  // 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, config);
+      }
+    })
+    .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();
+    });
+  }
+}
diff --git a/src/useDataApiHook-example/index.js b/src/useDataApiHook-example/index.js
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+import React, { useState, useEffect } from 'react';
+import axios from 'axios';
+
+const useDataApi = url => {
+  const [isLoading, setLoading] = useState(false);
+  const [data, setData] = useState(null);
+
+  useEffect(async () => {
+    setLoading(true);
+
+    const result = await axios(url);
+
+    setLoading(false);
+    setData(result.data);
+  }, []);
+
+  return { data, isLoading };
+};
+
+function App() {
+  const { data, isLoading } = useDataApi(
+    'http://hn.algolia.com/api/v1/search?query=redux',
+  );
+
+  if (isLoading) {
+    return <div>Loading ...</div>;
+  }
+
+  if (!data) {
+    return null;
+  }
+
+  return (
+    <ul>
+      {data.hits.map(item => (
+        <li key={item.objectID}>
+          <a href={item.url}>{item.title}</a>
+        </li>
+      ))}
+    </ul>
+  );
+}
+
+export default App;
diff --git a/src/useDataApiHook-example/test.js b/src/useDataApiHook-example/test.js
@@ -0,0 +1,9 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+import App from './';
+
+it('renders without crashing', () => {
+  const div = document.createElement('div');
+  ReactDOM.render(<App />, div);
+  ReactDOM.unmountComponentAtNode(div);
+});
diff --git a/src/useEffect-example/index.js b/src/useEffect-example/index.js
diff --git a/src/useEffect-example/test.js b/src/useEffect-example/test.js
diff --git a/src/useState-example/index.js b/src/useState-example/index.js
diff --git a/src/useState-example/test.js b/src/useState-example/test.js
