使用AJAX的带有参数的PHP POST不起作用

Question

I'm using AJAX to call a PHP script, and passing some parameters.

The PHP script is creating a PDF using FPDF. The values that I'm passing to the PHP script should only be used to concatenate to another string within the script.

The AJAX is calling the PHP script and the PDF is generating as it should, but the only problem is that the parameters coming up as empty. I'm not sure what I'm doing wrong and it is driving me crazy...

Here is my HTML :

<input type="submit" value="Download Completed DA190" onclick="printCompletedForm()" />
<script type="text/javascript">

function printCompletedForm()
{
    var testDate = "2012-08-19";

    $.ajax({  
        type: "POST",  
        url: "saveZeroRelease.php",
        data: {testdate : testDate},
        success: function(msg){

        },
        error: function(msg){

        }
    });
}

</script>

Here is my PHP :

$testDate = $_POST['testdate'];


$pdf = new PDF_MC_Table();
$pdf->Open();
$pdf->AddPage();
$pdf->SetFont('Arial','',8);
$pdf->Cell(150,10,'Certificate of foreign Currency usage in respect of materials and components in terms of the notes to rebate item ',1);
$pdf->SetFont('Arial','',10);
$pdf->Cell(40,10,'Form C1',1);
$pdf->Ln(10);
$pdf->Cell(190,10,'NOTE:',1);
$pdf->Ln(10);
$pdf->MultiCell(190,10,'Certificate Number:      Effective Date :'.$testDate.'  
Replaces Certificate No:_________________                                                        Effective Date :________________',1);
$pdf->Output();

I don't know what I'm doing wrong. Any help please guys!

Answer 1

First, in your JavaScript, wrap your code inside;

$(document).ready( function() {
//your code here
});

And don't forget to link your jQuery file like;

<script type="text/javascript" src="jquery.js"></script>

Also, in your php, change;

$testDate = $_POST['testdate'];

to

$testDate = $_POST["testdate"];

Hope this helps.

Answer 2

It looks like the default behavior of submitting the form is triggered and executed before your AJAX call has time to do everything you're asking it to. Look into event.preventDefault() to override the submit handler entirely. When the form is submitted, your function will then handle everything from making the $.ajax POST, and then redirecting the user as necessary.