BI Wordle

This will be the “frame” of our applications UI. Notice the \ directive, which serves as the insertion point of our pages.

### 2.2. Create the home page component
To generate a new component, called home-page, run the following command:

ng g c pages/home-page –skip-selector

*Note: In the Angular terminology we usually differentiate three types of components:
– **dumb/pure components:** their state depends entirely on ther inputs, therefore they are the most low-level and reusable of the three.
– **smart components:** smart components are usually more “wired together” with the application, they depend on services, inject dependencies, etc. They usually contain dumb components and are not really reusable themselves.
– **page components:** page components are smart components which are loaded through routing, therefore they don’t need HTML selectors, as they aren’t instantiated from HTML, but based on the route.

The home page component is of the former, a page component. That’s why we used the `–skip-selector` flag and why we have to add it to the routing.

Update the routing config, by setting our new home-page as the default page in the **app-routing.module.ts**. Don’t forget to import the component!

const routes: Routes = [
pathMatch: ‘full’,
redirectTo: ‘home’
path: ‘home’,
component: HomePageComponent

Replace the home-page.component.html with the following code:

Welcome to BI-Wordle!

In this game you will have to guess a 5 letter long word! After each guess, you will see whether the chosen letter:

Start Game!

This is a short description of the game, and a button, which will lead us to the game screen, using the routerLink directive.

*Note: notice the [ ] for propery binding.*

## 3. Guided task: Implementing the game logic
In the next part, we will implement the gamelogic itself.

### 3.1. Models
Create a folder under the app folder named model! Under this folder, we will create two files, the first is:

**app/model/guess-result.ts**:
export enum GuessResult {
NOT_TRIED,
WRONG_POSITION,
GOOD_POSITION
This enum contains the possible matches of a character in a guess.

**app/model/guess.ts**:
import { GuessResult } from “./guess-result”;

export interface Guess {
word: string;
matches: GuessResult[];

export const ALPHABET: string[] = [“A”,”B”,”C”,”D”,”E”,”F”,”G”,”H”,”I”,”J”,”K”,”L”,”M”,”N”,”O”,”P”,”Q”,”R”,”S”,”T”,”U”,”V”,”W”,”X”,”Y”,”Z”];
export const MAX_NUMBER_OF_GUESSES = 6;

This interface describes how a guess object looks like, some usefull constants are also defined in this file.

### 3.2. Game service
Let’s create the game service! Run the following command:
ng g s services/game

Replace the contents of the newly generated game.service.ts with the follwing:

import { HttpClient } from
import { Injectable } from
import { MAX_NUMBER_OF_GUESSES } from ‘../model/guess’;
import { GuessResult } from ‘../model/guess-result’;
import { tap } from ‘rxjs’;

@Injectable({
providedIn: ‘root’
export class GameService {

private word: string = ”;
private wordList: Array = [];
private guesses: Array = [];

constructor(private http: HttpClient) {}

initWordList() {
// We load the words from a static file
return this.http.get(‘assets/json/word-list.json’).pipe(
tap(result => {
this.wordList = result;

* Starts the game by selecting a random word from the list.
startGame() {
this.word = this.wordList[Math.round(Math.random() * this.wordList.length)];
console.log(‘Game starting, the word is ‘ + this.word);

* Checks whether the given list is in the word list.
* @param guessedWord
* @returns
isInWordList(guessedWord: string): Boolean {
return this.wordList.indexOf(guessedWord.toLowerCase()) != -1

* Evaluates a guess.
* @param guessedWord
* @returns
guess(guessedWord: string): GuessResult[] {
guessedWord = guessedWord.toLowerCase();
this.guesses.push(guessedWord);
return this.calculateMatches(guessedWord);

* Returns whether the game is finished yet.
* @returns
isFinished(): boolean {
return (this.guesses.length != 0 && this.guesses[this.guesses.length – 1] == this.word)
|| this.guesses.length >= MAX_NUMBER_OF_GUESSES;

* Calculates the guess result for each character in the given word.
* @param word
* @returns
calculateMatches(word: string): GuessResult[] {
let matches = Array();
for (let i = 0; i < 5; i++) { let char = word.charAt(i); if (this.word.charAt(i) == char) { matches.push(GuessResult.GOOD_POSITION); } else if (this.word.indexOf(char) != -1) { matches.push(GuessResult.WRONG_POSITION); matches.push(GuessResult.NO_MATCH); return matches; * Returns whether the given character was guessed in any position. * @param char * @returns charResult(char: string): GuessResult { let result = GuessResult.NOT_TRIED; for (let guess of this.guesses) { let guessResult = this.calculateMatches(guess); // Go over the characters of each word for (let i = 0; i < 5; i++) { // If the guessed char is the current char if (char.toLowerCase() == guess[i]) { if (result == GuessResult.NOT_TRIED) { // If it was tried at least once, we can be sure that the result would be at least NO MATCH (possibly better) result = GuessResult.NO_MATCH; if (guessResult[i] == GuessResult.GOOD_POSITION) { // If we find a GOOD POSITION, we can disregard each other finds and return that as our result. return GuessResult.GOOD_POSITION; } else if (guessResult[i] == GuessResult.WRONG_POSITION) { // Else, if we find a WRONG POSITION, we save it as the "next best result" but we keep searching result = GuessResult.WRONG_POSITION; return result; This implements the core game logic, let's study the main parts of it! In the constructor, we inject the `HttpClient`, which is a service used to make HTTP request. To make it available for our service, we must provide first! Add the following to the **app.module.ts**, at the appropriate places! import { HttpClientModule } from imports: [ HttpClientModule In the `initWordList()` function, we will use the `HttpClient` to download the list of possible words. This **word-list.json** is available in the current repository. [Download](assets/word-list.json) it and place it under the **assets/json** directory. Lets examine the remaining functions! Each of their comments will describe what they do. ## 4. Guided task: Game UI In this part, we will create the game page and associated components, which will be used as the main UI for playing the game. ### 4.1. Create the match color pipe The `GuessResult` enum describes the possible outcomes of a guess. A letter can be either `NOT_TRIED`, `NO_MATCH`, `WRONG_POSITION` or `GOOD_POSITION`. However to indicate it to the user, we must display different colors. To overcome this issue, we will use a pipe. A pipe is an Angular component used to transform data for display purposes. Pipes are very useful for formatting data, as omplex transformation logic can be implemented in them, they are used for date formatting, localization, etc. To create a new one, run the following command: ng g p pipes/match-color Replace the content of the newly generated pipe (**match-color.pipe.ts**), with the following: import { Pipe, PipeTransform } from import { GuessResult } from '../model/guess-result'; name: 'matchColor' export class MatchColorPipe implements PipeTransform { * Transforms the value of a GuessReuslt to a color (green, yellow, gray or black) * @param value * @param args * @returns transform(value: GuessResult): string { switch (value) { case GuessResult.GOOD_POSITION: return "#00AA00"; case GuessResult.NOT_TRIED: return "#808080"; case GuessResult.WRONG_POSITION: return "#DDDD00"; case GuessResult.NO_MATCH: return "#000000"; ### 4.2. Create the letter component The letter component will be out first real reusable, dumb component. Its purpose is to disaply a single letter of a guess. Create it with the following command: ng g c components/letter Replace the content of the **letter.component.ts** with the following: import { Component, Input, OnInit } from import { GuessResult } from 'src/app/model/guess-result'; @Component({ selector: 'app-letter', templateUrl: './letter.component.html', styleUrls: ['./letter.component.scss'] export class LetterComponent implements OnInit { @Input() letter: string = ''; @Input() result: GuessResult = GuessResult.NOT_TRIED; constructor() {} ngOnInit(): void {} Notice the two fields annotated with the decorator. and are used to facilitate the transfer of data between parent and child components. In this case, it means that the fields `letter` and `result` can be given a value by the parent component. Replace the contents of the **letter.component.html** with the following:
In this HTML template code, we bind the value attribute to the value field, using property binding. We also bind the style attribute, using the previously created pipe to the value of the result.

Lets add some styling to our component, insert the following into the **letter.component.scss**:

width: 60px;
height: 60px;
margin-left: 5px;
margin-right: 5px;
text-align: center;
font-size: 30px;

### 4.3. Create the guess component
The guess component will be used to represent a guess. A guess is made up of 5 letters, so here, we will re-use the previously created letter component.

Generate the guess component by running:
ng g c components/guess

Replace the contents of the **guess.component.ts** with the following:
import { Component, Input, OnInit } from
import { Guess } from ‘src/app/model/guess’;

@Component({
selector: ‘app-guess’,
templateUrl: ‘./guess.component.html’,
styleUrls: [‘./guess.component.scss’]
export class GuessComponent implements OnInit {

@Input() guess: Guess = {
matches: [],

constructor() {}

ngOnInit(): void {

Replace the contents of th **guess.component.html** with the following: