Why session value in php keep incrementing every time the page refreshed - php

Question

I am new to PHP and I am using session variables to create shopping cart, as I need to increment the number of items in the cart, I use session variables. However, this variable keep increment every time the page refreshed/reload, which increment the number of items.
<?php
session_start();
if (!isset($_SESSION['items'])){
$_SESSION['items'] = 0;
}
function increament_items(){
$_SESSION['items']++;
}
?>
and in HTML I have this
<a id="laptop" href="index.php" onclick="<?php increament_items() ?>",title="header=[Add to cart] body=[ ] fade=[on]">
I have tried to use form using post/get and still the same.
any help?
thanks

Answer 1

Php, as it is not a client language, will not work "onclick", but every time the code
<a id="laptop" href="index.php" onclick="<?php increament_items() ?>",title="header=[Add to cart] body=[ ] fade=[on]">
Is loaded.
So, you could use something like this to solve your problem.
1) Add at the end of your php code this:
if($_GET['add']==1){
increament_items();
}
2a) Then, replace your html code with this one
<a id="laptop" href="nameofyourphppage.php?add=1">Add</a>
2b) Or, if you prefer, after having included jquery library (*) into html page, use the following one:
<script>
function openLink(url)
{$("#add").html('Loading...');
$("#add").load(url, function (responseText, textStatus, req) {
if (textStatus == "error") {
$("#add").html('An error occurred');
}
});
}
</script>
<a id="laptop" href="javascript:openLink('nameofyourphppage.php?add=1')">Add</a>
<div id="add"></div>
The second solution will run the php code without the user leaving the html page.
(*)To include the jquery library, put into the head section of your html page this code:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>