Export php data to xls from a link

Question

I’m making a link, that when the user clicks on it should generate an xls file. The link has the data-attributes and must pass these attributes to the.php page and generate the xls. I tried to do with jquery and it’s not working, is there some other way?

<a href="#" id="xls" data-unidade="203" data-tema="1">
    Gerar XLS
</a>

The jquery

$(document).ready(function() {
    $('#xls').click(function(event) {
        event.preventDefault();

        $.ajax({
            type: 'POST',
            url : 'produto/exportXls',
            data: {
                'tema_id' : $(this).data('tema'),
                'unidade_id' : $(this).data('unidade')
            }
        });
    });
});

php that creates the table to generate the xls

$html = '<table><tr>';
$html .= '<td colspan="3">Planilha teste</tr>';
$html .= '</tr>';
$html .= '<tr><td><b>Coluna 1</b></td><td><b>Coluna 2</b></td><td><b>Coluna 3</b></td></tr>';
$html .= '<tr><td>L1C1</td><td>L1C2</td><td>L1C3</td></tr>';
$html .= '<tr><td>L2C1</td><td>L2C2</td><td>L2C3</td></tr>';
$html .= '<tr><td>L3C1</td><td>L3C2</td><td>L3C3</td></tr>';
$html .= '</table>';

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D,d M YH:i:s") . " GMT");
header("Cache-Control: no-cache, must-revalidate");
header("Pragma: no-cache");
header("Content-type: application/x-msexcel");
header("Content-Disposition: attachment; filename=arquivo.xls" );
header("Content-Description: PHP Generated Data" );
// Envia o conteúdo do arquivo
echo $html;

Only it’s not happening...

Answer 1

In a free translation of the words of John Culviner, creator of the plugin jQuery File Download:

Javascript, by design, does not have the ability to perform low-level tasks on its users' computer for security reasons. Initializing a download dialog is one such limitation.

So anyway, you will have to generate the file on your server and have a valid URI that points to it. With PHP you can do something simple like using file_put_contents()

Once this is done, a crude solution would be callback successfully manually redirect the browser to the URI of that resource:

$.ajax({
    url: 'path/to/server/action',
    data: {
        'tema_id': $(this).data('tema'),
        'unidade_id': $(this).data('unidade')
    },
    success: function (data) {
        window.location.href='arquivo.xls';
    }
});

But that’s not very appealing to modern web standards. With the above plugin, not only do you compose a specific solution, but you offer a more elegant way of handling errors.

When the server responds by requesting that the response be treated as a download, if successful, the browser does not change the page the user is on and displays the appropriate dialog box.

But when there is an error (file does not exist, for example), the browser is redirected to the default 404 page which may even be written in Korean which is frustrating for the user.

Answer 2

1) Change the PHP call to a traditional, non-ajax link;

2) add the next header to force the download:

header("Content-type: application/force-download");