Question

I wrote code below that is working perfectly for displaying the results of my sales tax calculation into a span tag. But, I am not understanding how to change the “total” value into a variable that I can work with.

<script type="text/javascript">
    function doStateTax(){
        var grandtotalX = $('#GRANDtotalprice').val();
        var statetaxX = $('#ddl').val();

        $.post('statetax.php',
        {statetaxX:statetaxX, grandtotalX:grandtotalX}, 
        function(data) {
        data = $.parseJSON(data);
        $('.products-placeholder').html(data.products);     
        $('.statetax-placeholder').html(data.statetax);     
        $('.total-placeholder').html(data.total);                               
        // ...
        });
        return false;
    };
</script>   

Currently, $(‘.total-placeholder’).html(data.total); is successfully placing the total number into here:

<span class="total-placeholder"></span> 

but how would I make the (data.total) part become a variable? With help figuring this out, I can pass that variable into a hidden input field as a “value” and successfully give a proper total to Authorize.net

I tried this and id didn’t work (see the testtotal part to see what I’m trying to accomplish)..

function(data) {
    data = $.parseJSON(data);
    $('.products-placeholder').html(data.products);     
    $('.statetax-placeholder').html(data.statetax);     
    $('.total-placeholder').html(data.total);       
    $testtotal = (data.total);                      
    // ...

Answer 1

If you are using a hidden field inside a form, you could do:

//inside $.post -> success handler.
$('.total-placeholder').html(data.total);
$('input[name=yourHiddenFieldName]', yourForm).val(data.total);

This will now be submitted along with the usual submit. Or if you want to access the data elsewhere:

var dataValue = $('input[name=yourHiddenFieldName]', yourForm).val();