Mastermind Settings Lab

---

Intro

In the lesson earlier you:

1. Learned how to use React Router to perform client-side routing.

2. Refactored the react-mastermind app to render a <GamePage> component at the root route.

3. Added a "Difficulty" <Link> to the <GamePage> used to navigate to a <SettingsPage> component.

4. As a practice exercise, added an additional <Route> with a path of /settings.

5. Created a minimal <SettingsPage> component that included a "HOME" <Link>.

In this lab, you'll continue to have fun building out react-mastermind using what you know about components, state, props, styling, methods, event handlers, routing and of course, JavaScript.

Set Up

The starter code for this lab is the same as the completed code from the React Router lesson.

To get set up for this lesson:

• cd into the folder for this lab.
• Install the Node modules: $ npm i
• Open the project in VS Code: $ code .
• Open a terminal in VS Code (ctrl + backtick)
• Start the React Dev Server: $ npm start

After the server starts up, you should see the following in the browser at localhost:3000:

Exercises

In this lab, you'll be adding the "Difficulty" setting functionality by completing the exercises below.

When completed, clicking the "Difficulty" link (styled as a button) will display the following:

As you can see, the settings page allows the player to change the difficulty level by selecting the number of colors available to choose from!

1. Currently, the <GamePage> component is relying on CSS classes defined in App.css. Refactor to cure this inappropriateness by copying the classes in App.css over to GamePage.css created during the lesson. Update the class names and update GamePage.jsx as required to use those class names.

2. Since both <App> & <GamePage> rely on a *-header-footer class with the same styling, refactor by renaming it to header-footer and putting it in index.css instead. Update App.js & GamePage.jsx to use header-footer, then you can delete GamePage-header-footer from GamePage.css and all of the CSS in App.css.

3. There will be three levels of difficulty: 'Easy'; 'Moderate'; and 'Difficult'. The game's difficulty will be held in a state property named difficulty. Add the difficulty property to state and initialize it with a value of 'Easy'. However, difficulty should not be "reset" if the player clicks the [New Game] button.

   Hint: Not resetting difficulty requires that it not be part of the object returned by the getInitialState method. Instead, difficulty should be initialized one time on the state state object within the constructor.

4. Using strings such as 'Easy', etc., to represent the difficulty is a fantastic way to access the array of colors for a particular difficulty level by using an object as a lookup. Refactor the colors array in App.js to be an object with keys of Easy, 'Moderate and Difficult which hold arrays of 4, 5, or 6 color strings respectively.

   Hint: The first couple of lines will look like this

   const colors = {
     Easy: ['#7CCCE5', '#FDE47F', '#E04644', '#B576AD'],
     ...

5. Changing the structure of colors expectedly broke the code because we were used to passing colors as an array to <GamePage>. Refactor the value that is assigned to the colors prop in <GamePage> such that the appropriate array in the refactored colors object is passed according to the value of the difficulty state property. With this step complete, the react-mastermind will be working again.

6. Now comes the "fun" part - building out the <SettingsPage> component so that:

   • It displays the UI shown above, including the three difficulty levels, with a button to select the level and the colors rendered as pegs. Also, theres a "Cancel" link used to return to the root without changing the difficulty.

   • The button to select the difficulty level is disabled for the currently selected difficulty.

   • Clicking one of difficulty buttons should update the difficulty state, initialize a new game, and programmatically route back to the <GamePage> page (root route).

   Hints:

   • You can try downloading and using React Developer Tools to browse components and check/modify state & props.

   • <SettingsPage> is going to need both the colors object and the difficulty state property.

   • Since difficulty lives in the state of <App>, guess where the method to update it will live.

   • You can reuse the handleNewGameClick method by passing it down to <SettingsPage> calling it to reset the game after you call the method to update the difficulty.

   • After updating difficulty & invoking handleNewGameClick, you can use the technique shown in the React Router lesson to programmatically route to /.

Choosing the Difficult level will result in the root route displaying this:

Good luck cracking the code!