CODEWITHSUNDEEP
javascriptphpjqueryjson
Prince
Prince

Reputation: 1192

Display an alert based on a json data

I am having 2 portions of code (php and javascript). In the PHP file, I use the function json_encode() to create a JSON data which will be sent to the Javascript file.

PHP FIle

<?php
if(isset($_GET["remove_code"]) && isset($_SESSION["products"]))
{
    $product_code   = filter_var($_GET["remove_code"], FILTER_SANITIZE_STRING); //get the product code to remove

    if(isset($_SESSION["products"][$product_code])) {
        unset($_SESSION["products"][$product_code]);
    }

    $total_items = count($_SESSION["products"]);

    if($total_items == 0){
        unset($_SESSION["products"]);
    }else{
        //Calculate total of items in the cart
        $total = 0;
        foreach($_SESSION["products"] as $product){ //loop though items and prepare html content

            $product_price = $product["price"];
            $product_quantity = $product["quantity"];

            $subtotal = $product_price * $product_quantity;

            $total += $subtotal;
        }
    }

    die(json_encode(array('items'=>$total_items, 'total'=>$total)));
}
?>

Javascript File

<script>
    $(document).ready(function(){
        $(".contentwrapper .content").on('click', 'a.removebutton', function() {
            var pcode = $(this).attr("data-code"); //get product code

            $.getJSON( "phpfile.php", {"remove_code":pcode}, function(data) {

                alert(data.items);// the total number of item
            });
    });
</script>

Anytime the query $.getJSON( "phpfile.php", {"remove_code":pcode}... is successful, an alert is displayed showing the data.items. The problem I am facing is that, when data.items is greater than or equal to 1 the alert is prompted, but when data.items is equal to 0, no alert is prompted.

Kindly help me solve this problem

Upvotes: 1

Views: 691

Answers (3)

paddybasi
paddybasi

Reputation: 82

Looks like a PHP error. $total variable is only declared inside the 'else' condition, so when ($total_items == 0) $total is undefined. But as you've called die(json_encode(array('items'=>$total_items, 'total'=>$total))); the server doesn't have a chance to complain (maybe returning no data and hence no alert). If you try declaring $total = 0 before your condition it should also fix the issue, without having to die early.

Upvotes: 1

Prince
Prince

Reputation: 1192

Adding die(json_encode(array('items'=>$total_items))); at the end of the condition if($total_items == 0) and it solves the problem. But I really can't explain what is happening. Up to now I do not really know the origin of the problem. Any explanation will be welcomed

Upvotes: 0

Theodore K.
Theodore K.

Reputation: 5176

One possibility is that actually data variable is undefined/null e.t.c., see this for example, second alert is not shown. Instead an error is shown on the browser console.

var data = {items:0};
alert(data.items);
data = null;
alert(data.items);

Upvotes: 0

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