createContent.php

<?php 
session_start();
include "navbar.php"; ?>
<?php 
    require_once 'Buisness/dbConfig.php';
    require_once 'Buisness/Course.cls.php';
    require_once 'Buisness/Subject.cls.php';
    require_once 'Buisness/Content.cls.php';
    require_once 'Buisness/Quiz.cls.php';
?>

<form action="creatingContent.php" method="post">
	<div class="container-fluid">
		<div class="row">
			<div class="col-sm-12 text-center">
				<div>
					<h2>Content Creation</h2>	
				</div>
			</div>
		</div>
		<div class="row">
			<div class="col-sm-4">
			</div>
			<div class="col-sm-4">
				<div class="form-group">	
					<label>Name:</label>
					<input type="text" class="form-control" id="contentName" placeholder="Enter content name" name="contentName" required="required"/>
				</div>
				<div class="form-group">
					<label>Text:</label>
					<textarea class="form-control" rows="5" name="contentText"></textarea>
				</div>
				<div class="form-group">
					<label>Subject:</label>
					<select class="form-control" name="contentSubject">
						<?php 
						 $subject = new Subject();
						  
						 if (isset($_GET["subject"])){
						      $subject->setId($_GET["subject"]);
						      $subject = $subject->findById($connectionId);
						      echo "<option value='".$subject->getId()."'>".$subject->getName()."</option>";
						 }
						 else {
						 
						      $course = new Course();
						      $courses = $course->findAll($connectionId);
						 
						 
						      $subjects = $subject->findAll($connectionId);
						 
						      foreach ($courses as $courseElement){
						          if ($courseElement->getMemberId() == $_SESSION["id"]){
						              echo "<optgroup label='".$courseElement->getName()."'>";
						              foreach ($subjects as $subjectElement){
						                  if($courseElement->getId() == $subjectElement->getCourseId()){
						                      echo "<option value='".$subjectElement->getId()."'>".$subjectElement->getName()."</option>";
						                  }
						              }
						              echo "</optgroup>";
						          }
						      }
						 }
						?>
					</select>
				</div>
				<div class="form-group">
					<label>Quiz:</label>
					<select class="form-control" name="contentQuiz">
					<option></option>
					<?php 
					$quiz = new Quiz();
					$quizs = $quiz->findAll($connectionId);
					
                    foreach($quizs as $quizElement){
                        if($quizElement->getMemberId() == $_SESSION["id"]){
					       echo "<option value='".$quizElement->getId()."'>".$quizElement->getName()."</option>";
                        }
                    }
                    
					?>
					</select>
				</div>
				<div class="text-center">
					<button type="submit" class="btn btn-primary" id="create" >Create</button>
				</div>
			</div>
			<div class="col-sm-4">
			</div>
		</div>
	</div>
</form>