PHP - Session array - prevent duplicate entrys - php

Question

This one is really bugging me, and can not find a easy solution.
On a detail view of a product, i set the info to a session, maximum 4:
$_SESSION['recent'][] = array(
'id' => $productimgfolder,
'title' => $product['Product']['title'],
'link' => $_SERVER['REQUEST_URI'],
'image' => 'img/products/'.$productimgfolder.'/'.$product['Product']['mainpicture']
);
$_SESSION['recent'] = array_slice($_SESSION['recent'],-4);
This part works, if i output the session:
edit image => this is wat happens if i reload the detail view
The part i'am struggling with is, when i reload a detail view, the info in the session is duplicated.
How can i prevent this from happening?
I tried it with in_array & array_unique, i'am doing something wrong

Answer 1

The easy solution:
if the id is unique, you can do like this:
if(!array_key_exists ($productimgfolder, $_SESSION['recent']))
{
$_SESSION['recent'][$productimgfolder] = array(
'id' => $productimgfolder,
'title' => $product['Product']['title'],
'link' => $_SERVER['REQUEST_URI'],
'image' => 'img/products/'.$productimgfolder.'/'.$product['Product']['mainpicture']
);
}
$_SESSION['recent']=array_slice($arr, -4, 4, true);
other wise you have to foreach the recent array and check for id in the loop...

Answer 2

A different solution may be;
array_unshift($sessionArray, $singleArrayElement);
if (count($sessionArray) > 4) {
array_pop($seassionArray);
};

Answer 3

You need to check isset
if(!isset($_SESSION['recent']))
{
$_SESSION['recent'] = array()
}
THEN YOU CAN CHECK IF SESSION IS EMPTY
if(empty($_SESSION['recent']))
{
//here you add your data
}
because you are using array push, on page reload it adds data unless you check if session is empty. if yes you add data to your session.