Inital quiz page and answer submission

ajax.php

@@ -0,0 +1,28 @@
+<?php
+use TestProject\Quiz;
+use TestProject\Question;
+require_once 'init.php';
+
+$quiz  = new Quiz( $_POST['quiz'] );
+$quest = new Question( $_POST['quest'] );
+
+$quest->saveAnswer( $_POST['user'], $_POST['ans'] );
+
+$questID_arr = Question::getList( $quiz->getID() );
+$index_int   = array_search( $quest->getID(), $questID_arr );
+
+$index_int++;
+$nextQuest = new Question( $index_int );
+$ans_arr   = $nextQuest->getAnswers();
+
+$data_arr = array(
+	'text' => $nextQuest->getText(),
+	'ans'  => array()
+);
+
+foreach( $ans_arr as $answer ){
+	$data_arr['ans'][] = array( 'id' => $answer->getID(), 'text' => $answer->getText() );
+}
+
+header( "content-type: application/json" );
+echo json_encode( $data_arr );

classes/question.class.php

@@ -5,8 +5,8 @@ namespace TestProject;
  * Question class
  */
 class Question extends Item {
-	private const tb_str      = 'question';
-	private const resulTb_str = 'question_result';
+	private const tb_str       = 'question';
+	private const resultTb_str = 'question_result';
 
 	private $text_str;
 	private $answers_arr;
@@ -73,4 +73,72 @@ class Question extends Item {
 	public function getAnswers(){
 		return $this->answers_arr;
 	}
+
+	/**
+	 * Calulate user's score and save to DB
+	 *
+	 * @param int $userID_int ID of user
+	 * @param int[] $ans_arr Array of answer IDs
+	 */
+	public function saveAnswer( int $userID_int, $ans_arr ){
+		$maxScore_int = 0;
+		$score_int    = 0;
+
+		foreach( $this->answers_arr as $answer ){
+			if ( $answer->isCorrect() ){
+				$maxScore_int++;
+
+				// User selected correct answer
+				if ( in_array( $answer->getID(), $ans_arr ) ){
+					$score_int++;
+				}
+			}
+		}
+
+		// Apply penalty if more answers selected than correct options
+		$diff_int = count( $ans_arr ) - $maxScore_int;
+		if ( $diff_int > 0 ){
+			$score_int -= $diff_int;
+		}
+		// Do not allow a negative score
+		if ( $score_int < 0 ){
+			$score_int = 0;
+		}
+
+		$db = DB::getDB();
+
+		// Check for existing answer
+		$row_arr = $db->select( self::resultTb_str, array( 'id' ), array( 'user' => $userID_int, 'question' => $this->id_int ) );
+		if ( empty( $row_arr ) ){
+			$db->insert(
+				self::resultTb_str,
+				array(
+					'user'     => $userID_int,
+					'question' => $this->id_int,
+					'score'    => $score_int
+				)
+			);
+		} else {
+			$db->update( self::resultTb_str, array( 'score' => $score_int ), array( 'id' => $row_arr[0]['id'] ) );
+		}
+	}
+
+	/**
+	 * Get a user's score for the question
+	 *
+	 * @param int $userID_int ID of user
+	 *
+	 * @return int Score
+	 */
+	public function getScore( int $userID_int ){
+		$db = DB::getDB();
+
+		$row_arr = $db->select( self::resultTb_str, array( 'score' ), array( 'user' => $userID_int, 'question' => $this->id_int ) );
+		if ( empty( $row_arr ) ){
+			// Question not answered
+			return 0;
+		}
+
+		return $row_arr[0]['score'];
+	}
 }

classes/quiz.class.php

@@ -6,7 +6,7 @@ namespace TestProject;
  */
 class Quiz extends Item {
 	private const tb_str      = 'quiz';
-	private const resulTb_str = 'quiz_result';
+	private const resultTb_str = 'quiz_result';
 
 	private $name_str;
 	private $maxScore_int;

quiz.js

@@ -0,0 +1,22 @@
+$( document ).ready( function() {
+	"use strict";
+
+	let questNum = 1;
+
+	$( "#question" ).on( "submit", function( event ){
+		event.preventDefault();
+		let ans = [];
+		$( "[name='answer']:checked" ).each( function( index, element ){
+			ans[ ans.length ] = element.value;
+		} );
+
+		$.post( 'ajax.php', {
+			user  : id.user,
+			quiz  : id.quiz,
+			quest : id.quest[ questNum - 1],
+			ans   : ans,
+		} ).done( function( data ){
+			console.log( data );
+		} );
+	} );
+} );

quiz.php

@@ -7,11 +7,13 @@ require_once 'init.php';
 $user = User::find( $_POST['email'], $_POST['name'] );
 $quiz = new Quiz( $_POST['quiz'] );
 
+$_SESSION['user_id'] = $user->getID();
+
 $questID_arr = Question::getList( $quiz->getID() );
 
 $quest1 = new Question( $questID_arr[0] );
 
-$_SESSION['user_id'] = $user->getID();
+$progress_num = 1 / count( $questID_arr ) * 100;
 ?>
 <html lang=en_GB>
 	<head>
@@ -59,6 +61,13 @@ $_SESSION['user_id'] = $user->getID();
 					</div>
 				</div>
 			</form>
+			<div class="row">
+				<div class="col">
+					<div class="progress">
+						<div class="progress-bar" role="progressbar" style="width: <?php echo $progress_num; ?>%">1 / <?php echo count( $questID_arr ); ?></div>
+					</div>
+				</div>
+			</div>
 		</div>
 		<script src="https://code.jquery.com/jquery-3.4.1.min.js" integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo=" crossorigin="anonymous"></script>
 		<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>