PHP: Session 2-Dimensional Array - Track Viewed Products

Question

I'm trying to create an array to display the last 5 products a customer has viewed.

The array is a 2 dimensional array like below...

$RView= array( array( ID => "1001", RefCode => "Ref_01", Name => "Name_01" ), ... array( ID => "1005", RefCode => "Ref_05", Name => "Name_05" ) );

The array values are retrieved from the products recordset and is designed to function as follows when a customer visits a product page.

• Page will check if a Session Array exists
• If yes, an array variable is created from existing Session
  If no, a new array is created.
• Array will add the new product details.
• Array will count if there are more than 5 existing products in the array.
• If yes, it will remove the oldest.
  If no, moves to next step.
• A Session is created/updated from the revised Array.

My current effort is attached below...
Many thanks for any help.

    <?php 
    session_start() 
    // Get or Create Array
    IF (isset($_SESSION['sessRView'])) {
    $RView = ($_SESSION['sessRView']); } 
    ELSE {
    $RView = array(array()); 
    }

    // Append currently viewed Product to Array
    array(array_unshift($RView, $row_rsPrd['PrdID'], $row_rsPrd['RefCode'], $row_rsPrd['Name']));

    // Check if more than 5 products exist in Array, if so delete.
    IF (sizeof($RView) > 5) {
    array(array_pop($RView)); }

    // Update Session for next page
    $_SESSION['sessRView'] = $RView;

    // Display Array
    for ($row = 0; $row < 5; $row++)
    {
    echo "<ul>";
        echo "<li><a href='?PrdID=".$RView[$row]["PrdID"]."'>".$RView[$row]["RefCode"]."</a> : ".$RView[$row]["Name"]."</li>";
    echo "</ul>";
    }
    ?>

Answer 1

It's more or less right - just 2 lines need to be changed.

1. There's no need for the extra array() around array_unshift and array_pop.
2. When you use array_unshift you're pushing an array of items (not the id/codes individually) - I think you mean array_unshift($RView, array($prodid,$name,...))
3. What if $RView doesn't have 5 elements? In that case you're accessing undefined array indices (which may or may not show an error). Change it to a foreach loop: e.g.
   foreach ($Rview as $prod) echo $prod['Name']...

It should work after you make these changes. You might want to clean up the coding style a bit, though :)

---

EDIT: Oh, I see, when you're referencing the array in the for loop it doesn't know that the array has "ProdID" and "Name" indices. When you make an array you have to define the indexes using the => operator.

• Add indexes to the array when you array_unshift:
  array_unshift($RView, array("ProdID" => $row_rsProd["ProdID"], "Name"...))

• If row_rsProd isn't too big, you can just tack the entire row_rsprod onto $RView.
  so change array_unshift(...) to just $RView[] = $row_rsProd
  This way the indexes are preserved.

• Alternatively you can change the indicies in the for loop to match. Right now the array you unshift onto $RView is 0-based - $RView[0][0] is the product ID for the first product, etc.
  So you can change the stuff in the foreach loop to
  echo "<li>..." $prod[0] $prod[1] $prod[2]

Hope that helps!