update,

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/App.css

@@ -0,0 +1,38 @@
+.App {
+  text-align: center;
+}
+
+.App-logo {
+  height: 40vmin;
+  pointer-events: none;
+}
+
+@media (prefers-reduced-motion: no-preference) {
+  .App-logo {
+    animation: App-logo-spin infinite 20s linear;
+  }
+}
+
+.App-header {
+  background-color: #282c34;
+  min-height: 100vh;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  font-size: calc(10px + 2vmin);
+  color: white;
+}
+
+.App-link {
+  color: #61dafb;
+}
+
+@keyframes App-logo-spin {
+  from {
+    transform: rotate(0deg);
+  }
+  to {
+    transform: rotate(360deg);
+  }
+}

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/App.js

@@ -0,0 +1,231 @@
+import React from "react";
+
+// 4.2. Go to class LoginButton. In its render() function, we are rendering a login button with the
+// handler function this.handleClick bound to the onclick event. Implement the function
+// handleClick(): If the input username and password are valid, use
+// this.props.handleStatusChange(xx, yy) received from class Lab7App to update the state
+// variables of Lab7App, where xx equals “true” and yy equals this.props.username received from
+// class Lab7App; otherwise, alert the message “Login failed!” Hint: you can use the provided
+// function checkValid() to check if the input username and password are valid, which returns true
+// if the inputs are included in the predefined array userDB, and returns false, otherwise. Read more
+// about the array find() function at https://developer.mozilla.org/en-
+// US/docs/Web/JavaScript/Reference/Global_Objects/Array/find
+
+class LoginButton extends React.Component {
+  constructor(props) {
+    super(props);
+    this.handleClick = this.handleClick.bind(this);
+    this.checkValid = this.checkValid.bind(this);
+  }
+
+  checkValid() {
+    let item = userDB.find((item) => {
+      return item.username == this.props.username && item.password == this.props.password;
+    });
+    if (item != undefined) return true;
+    else return false;
+  }
+
+  // step 4.2
+  handleClick() {
+    if (this.checkValid()) {
+      this.props.handleStatusChange(true, this.props.username);
+    } else {
+      // otherwise, alert the message “Login failed!”
+      alert("Login failed!");
+    }
+  }
+
+  render() {
+    return <button onClick={() => this.handleClick()}>Login</button>;
+  }
+}
+
+class Contents extends React.Component {
+  constructor(props) {
+    super(props);
+    this.state = {
+      topics: topicsDB,
+    };
+    this.handleTopicsChange = this.handleTopicsChange.bind(this);
+  }
+
+  // step 7
+  // Step 7. Implement filtering of topics list
+  // Now implement the function handleTopicsChange() in class Contents as follows: if value of the
+  // argument option is not “all” (i.e., it is one of the three sections instead), apply filter() function on
+  // topicsDB to obtain a filtered topics array where each topic’s section is option (learn more about
+  // JavaScript Array filter method at https://developer.mozilla.org/en-
+  // US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter), and set the state variable
+  // Topics to be the filtered array; otherwise, set the state variable Topics to be topicsDB. Note that
+  // you need to use this.setState() to change a state variable’s value.
+  handleTopicsChange(option) {
+    if (option == "all") {
+      this.setState({ topics: topicsDB });
+    } else {
+      this.setState({ topics: topicsDB.filter((o) => o.section == option) });
+    }
+  }
+
+  render() {
+    const topics = this.state.topics;
+    return (
+      <div id="contents">
+        <DropDownList handleTopicsChange={this.handleTopicsChange} />
+        {
+          // Step 5. Render topics list in class component Contents
+          // Go to class Contents, which has a state of one key-value pair: topics stores the list of topics to be
+          // shown on the page, initialized using the given array topicsDB. Complete the render() function of
+          // class Contents: within { }, apply map() function on topics to create a number of <p> elements,
+          // each presenting information of one topic in the topics array as <p>Section: {topic.section}; Topic
+          // Name: {topic.topic}</p>. The handler function handleTopicsChange() is to change the state
+          // variable topics upon selecting a different option in the drop-down list (to be implemented later).
+
+          topics.map((topic) => {
+            return (
+              <>
+                <p>
+                  Section: {topic.section}; Name: {topic.topic}
+                </p>
+              </>
+            );
+          })
+        }
+      </div>
+    );
+  }
+}
+
+function DropDownList(props) {
+  var key_pool = {};
+  const getUniq = (value_in) => {
+    if (key_pool[value_in] != undefined) return false;
+
+    key_pool[value_in] = "";
+    return true;
+  };
+  return (
+    <div>
+      <b>Choose one section: </b>
+
+      {
+        // Step 6. Render a drop-down list in function component DropDownList
+        // Now go to function DropDownList, which receives the handler function handleTopicsChange of
+        // class Contents in its props. Complete its render() function as follows: remove "{/* step 6*/}", and
+        // in its place, create a drop-down list using the <select> element with four options (with values
+        // “all”, “section-1”, “section-2” and “section-3”, respectively). The option “all” should be
+        // associated with the attribute “selected” as the default option. Add an event handler function to
+        // onChange event on the <select> element (to track the change of selected option and update
+        // topics list accordingly), which should be e => props.handleTopicsChange(e.target.value).
+      }
+      <></>
+      {
+        <select onChange={(e) => props.handleTopicsChange(e.target.value)}>
+          <option selected value="all">
+            all
+          </option>
+          {
+            // topicsDB
+            //  get unique by section
+            //  extract section
+            //  sort before exit
+          }
+          {topicsDB
+            .filter((t) => getUniq(t.section))
+            .map((ut) => ut.section)
+            .sort()
+            .map((ts) => (
+              <option value={ts}>{ts}</option>
+            ))}
+        </select>
+      }
+    </div>
+  );
+}
+
+class Lab7App extends React.Component {
+  constructor(props) {
+    super(props);
+    this.state = {
+      isLogin: false,
+      loginName: "",
+      inputUserName: "",
+      inputUserPswd: "",
+    };
+    this.handleInputChange = this.handleInputChange.bind(this);
+    this.handleStatusChange = this.handleStatusChange.bind(this);
+  }
+
+  // step 3
+  handleInputChange(event) {
+    let target = event.target;
+    let name = target.name;
+    let value = target.value;
+    this.setState({ [name]: value });
+  }
+
+  handleStatusChange(newStatus, loginName) {
+    const isUserLoggedIn = (login_status) => login_status == true;
+
+    if (isUserLoggedIn(newStatus)) {
+      this.setState({ isLogin: newStatus, loginName: loginName });
+    } else {
+      this.setState({ isLogin: newStatus, loginName: loginName, inputUserName: "", inputUserPswd: "" });
+    }
+  }
+
+  render() {
+    if (!this.state.isLogin) {
+      return (
+        <div>
+          <p>Fill in username and password and click the button to log in</p>
+          <input type="text" name="inputUserName" placeholder="username" value={this.state.inputUserName} onChange={(e) => this.handleInputChange(e)} />
+          <input type="password" name="inputUserPswd" placeholder="password" value={this.state.inputUserPswd} onChange={(e) => this.handleInputChange(e)} />
+
+          {
+            // 4.1. In the render() function of Lab7App, render the
+            //   LoginButton component. The LoginButton component receives three props:
+            //   1. username: which equals the value of state variable inputUserName;
+            //   2. password: which equals the value of state variable inputUserPswd;
+            //   3. handleStatusChange: which equals this.handleStatusChange. We have provided the
+            //   implementation of function handleStatusChange(), which receives the login status (boolean
+            //   type) and the name of the logged-in user (string type) as arguments, and set the state
+            //   variables isLogin and loginName to the argument values, respectively. 
+          }
+
+          <LoginButton username={this.state.inputUserName} password={this.state.inputUserPswd} handleStatusChange={this.handleStatusChange} />
+        </div>
+      );
+    } else {
+      return (
+        <div>
+          <p>Welcome {this.state.loginName}!</p>
+          <button onClick={() => this.handleStatusChange(false, "")}>Logout</button>
+          {/* 4.3. Go to class Lab7App. In the render() function, add an onClick event handler to the logout button, which is an
+          arrow function ()=>this.handleStatusChange() where handleStatusChange() receives a “false” value and an empty string as arguments. */}
+          <Contents />
+        </div>
+      );
+    }
+  }
+}
+
+const userDB = [
+  { username: "Alex", password: "123" },
+  { username: "Bob", password: "231" },
+  { username: "Jack", password: "321" },
+];
+
+const topicsDB = [
+  { section: "section-1", topic: "CSS" },
+  { section: "section-1", topic: "HTML" },
+  { section: "section-1", topic: "WWW" },
+  { section: "section-2", topic: "JaveScript" },
+  { section: "section-2", topic: "MongoDB" },
+  { section: "section-2", topic: "NodeJS" },
+  { section: "section-3", topic: "JQuery" },
+  { section: "section-3", topic: "React" },
+  { section: "section-3", topic: "Vue" },
+];
+
+export default Lab7App;

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/App.test.js

@@ -0,0 +1,8 @@
+import { render, screen } from '@testing-library/react';
+import App from './App';
+
+test('renders learn react link', () => {
+  render(<App />);
+  const linkElement = screen.getByText(/learn react/i);
+  expect(linkElement).toBeInTheDocument();
+});

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/index.css

@@ -0,0 +1,23 @@
+body {
+  margin: 0;
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
+    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
+    sans-serif;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+code {
+  font-family: source-code-pro, Menlo, Monaco, Consolas, 'Courier New',
+    monospace;
+}
+
+#root{
+  text-align: center;
+}
+
+#contents{
+  text-align: left;
+  margin-left: 40%;
+  margin-top: 2em;
+}

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/index.js

@@ -0,0 +1,17 @@
+import React from "react";
+import ReactDOM from "react-dom/client";
+import "./index.css";
+import Lab7App from "./App";
+import reportWebVitals from "./reportWebVitals";
+
+const root = ReactDOM.createRoot(document.getElementById("root"));
+root.render(
+  <React.StrictMode>
+    <Lab7App />
+  </React.StrictMode>
+);
+
+// If you want to start measuring performance in your app, pass a function
+// to log results (for example: reportWebVitals(console.log))
+// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
+reportWebVitals();

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/logo.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 841.9 595.3"><g fill="#61DAFB"><path d="M666.3 296.5c0-32.5-40.7-63.3-103.1-82.4 14.4-63.6 8-114.2-20.2-130.4-6.5-3.8-14.1-5.6-22.4-5.6v22.3c4.6 0 8.3.9 11.4 2.6 13.6 7.8 19.5 37.5 14.9 75.7-1.1 9.4-2.9 19.3-5.1 29.4-19.6-4.8-41-8.5-63.5-10.9-13.5-18.5-27.5-35.3-41.6-50 32.6-30.3 63.2-46.9 84-46.9V78c-27.5 0-63.5 19.6-99.9 53.6-36.4-33.8-72.4-53.2-99.9-53.2v22.3c20.7 0 51.4 16.5 84 46.6-14 14.7-28 31.4-41.3 49.9-22.6 2.4-44 6.1-63.6 11-2.3-10-4-19.7-5.2-29-4.7-38.2 1.1-67.9 14.6-75.8 3-1.8 6.9-2.6 11.5-2.6V78.5c-8.4 0-16 1.8-22.6 5.6-28.1 16.2-34.4 66.7-19.9 130.1-62.2 19.2-102.7 49.9-102.7 82.3 0 32.5 40.7 63.3 103.1 82.4-14.4 63.6-8 114.2 20.2 130.4 6.5 3.8 14.1 5.6 22.5 5.6 27.5 0 63.5-19.6 99.9-53.6 36.4 33.8 72.4 53.2 99.9 53.2 8.4 0 16-1.8 22.6-5.6 28.1-16.2 34.4-66.7 19.9-130.1 62-19.1 102.5-49.9 102.5-82.3zm-130.2-66.7c-3.7 12.9-8.3 26.2-13.5 39.5-4.1-8-8.4-16-13.1-24-4.6-8-9.5-15.8-14.4-23.4 14.2 2.1 27.9 4.7 41 7.9zm-45.8 106.5c-7.8 13.5-15.8 26.3-24.1 38.2-14.9 1.3-30 2-45.2 2-15.1 0-30.2-.7-45-1.9-8.3-11.9-16.4-24.6-24.2-38-7.6-13.1-14.5-26.4-20.8-39.8 6.2-13.4 13.2-26.8 20.7-39.9 7.8-13.5 15.8-26.3 24.1-38.2 14.9-1.3 30-2 45.2-2 15.1 0 30.2.7 45 1.9 8.3 11.9 16.4 24.6 24.2 38 7.6 13.1 14.5 26.4 20.8 39.8-6.3 13.4-13.2 26.8-20.7 39.9zm32.3-13c5.4 13.4 10 26.8 13.8 39.8-13.1 3.2-26.9 5.9-41.2 8 4.9-7.7 9.8-15.6 14.4-23.7 4.6-8 8.9-16.1 13-24.1zM421.2 430c-9.3-9.6-18.6-20.3-27.8-32 9 .4 18.2.7 27.5.7 9.4 0 18.7-.2 27.8-.7-9 11.7-18.3 22.4-27.5 32zm-74.4-58.9c-14.2-2.1-27.9-4.7-41-7.9 3.7-12.9 8.3-26.2 13.5-39.5 4.1 8 8.4 16 13.1 24 4.7 8 9.5 15.8 14.4 23.4zM420.7 163c9.3 9.6 18.6 20.3 27.8 32-9-.4-18.2-.7-27.5-.7-9.4 0-18.7.2-27.8.7 9-11.7 18.3-22.4 27.5-32zm-74 58.9c-4.9 7.7-9.8 15.6-14.4 23.7-4.6 8-8.9 16-13 24-5.4-13.4-10-26.8-13.8-39.8 13.1-3.1 26.9-5.8 41.2-7.9zm-90.5 125.2c-35.4-15.1-58.3-34.9-58.3-50.6 0-15.7 22.9-35.6 58.3-50.6 8.6-3.7 18-7 27.7-10.1 5.7 19.6 13.2 40 22.5 60.9-9.2 20.8-16.6 41.1-22.2 60.6-9.9-3.1-19.3-6.5-28-10.2zM310 490c-13.6-7.8-19.5-37.5-14.9-75.7 1.1-9.4 2.9-19.3 5.1-29.4 19.6 4.8 41 8.5 63.5 10.9 13.5 18.5 27.5 35.3 41.6 50-32.6 30.3-63.2 46.9-84 46.9-4.5-.1-8.3-1-11.3-2.7zm237.2-76.2c4.7 38.2-1.1 67.9-14.6 75.8-3 1.8-6.9 2.6-11.5 2.6-20.7 0-51.4-16.5-84-46.6 14-14.7 28-31.4 41.3-49.9 22.6-2.4 44-6.1 63.6-11 2.3 10.1 4.1 19.8 5.2 29.1zm38.5-66.7c-8.6 3.7-18 7-27.7 10.1-5.7-19.6-13.2-40-22.5-60.9 9.2-20.8 16.6-41.1 22.2-60.6 9.9 3.1 19.3 6.5 28.1 10.2 35.4 15.1 58.3 34.9 58.3 50.6-.1 15.7-23 35.6-58.4 50.6zM320.8 78.4z"/><circle cx="420.9" cy="296.5" r="45.7"/><path d="M520.5 78.1z"/></g></svg>

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/reportWebVitals.js

@@ -0,0 +1,13 @@
+const reportWebVitals = onPerfEntry => {
+  if (onPerfEntry && onPerfEntry instanceof Function) {
+    import('web-vitals').then(({ getCLS, getFID, getFCP, getLCP, getTTFB }) => {
+      getCLS(onPerfEntry);
+      getFID(onPerfEntry);
+      getFCP(onPerfEntry);
+      getLCP(onPerfEntry);
+      getTTFB(onPerfEntry);
+    });
+  }
+};
+
+export default reportWebVitals;

james_endl/COMP3322A-Lab-7-React/code/myreactapp/src/setupTests.js

@@ -0,0 +1,5 @@
+// jest-dom adds custom jest matchers for asserting on DOM nodes.
+// allows you to do things like:
+// expect(element).toHaveTextContent(/react/i)
+// learn more: https://github.com/testing-library/jest-dom
+import '@testing-library/jest-dom';