How to make permission to view the page?

Question

PHP

I didn’t quite understand how to google) Sorry. There is a site that needs to make a pop-up window when viewing certain articles "Are you 18 years old or not?" and, accordingly, either allow or not view the article (and if "no:, it should go somewhere). But not on the entire site. It still needs to be connected with Bitrix. In which direction to google?

Answer 1

<?
  session_start();
  if($_POST['is18years'] == 'yes' || $_POST['is18years'] == 'no') $_SESSION['is18years'] = $_POST['is18years'];
  if(isset($_SESSION['is18years'])) {
    if($_SESSION['is18years'] == 'no') {
      header("Location: /access_denied.html");
        	exit; 
    }
  }
?>

<?
  if(!isset($_SESSION['is18years'])):
?>
<div class="body_overhead">
  <div class="overhead_window">
  <div class="oh_wnd_header">
    <p>Доступ к сайту могут осуществлять только лица, достигшие возраста 18 лет</p>
    <p style="font-weight: bold;">Вам уже есть 18 лет?</p>
    <p>
      <span style="color: green" class="is18years yes18">ДА, мне уже есть 18 лет</span> | <span style="color: red" class="is18years no18">НЕТ, мне еще нет 18 лет</span>
    </p>
  </div>
  </div>
</div>
<style>
  .body_overhead {
    position: fixed;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.95);
    z-index: 999999999;
  }
  .overhead_window {
    top: 10%;
    left: 30%;
    width: 40%;
    background: #fff;
    position: relative;
  }
  .oh_wnd_header {
    padding: 20px;
    color: #333;
    text-align: center;
  }
  .is18years {
  cursor: pointer;
  }
</style>
<?
  endif;
?>
<script>
  // проверка на 18 лет
  $('.is18years').click(function(){
    if($(this).hasClass('yes18') || $(this).hasClass('no18')) {
      var is18years = $(this).hasClass('yes18') ? 'yes' : 'no' 
      $.ajax({
  				type: "POST",
        	context: document.head,
 				data: { is18years: is18years },
        	success: function(){
        		if(is18years === 'yes') {
        			$('.body_overhead').hide()
        		} else {
        			document.location.href = '/access_denied.html'
        		}
       	}
      })	    
    }
  })
</script>

Answer 2

modal window + cookies