Downloading multiple PDF files simultaneously

Question

I need to download PDF files simultaneously by selecting textboxes and clicking on a Download button. For now, I am able to click the Download button next to each item to download the item. I need to have another button which will be used for bulk download of the files.

Below is the code for the Download button next to each item.

<td><a href="print_voucher.php?em_id=<?php echo $row['voucher_id'] ?>" download="print_voucher.php?em_id=<?php echo $row['voucher_id'] ?>"> Download </a></td>

Below is the code for the whole table displaying the items to download.

<form action="createzip.php" method="post">
    <table id="selection_table" class="data-table table stripe hover nowrap">
        <thead>
            <tr>
                <div class="col-md-6">
                </div>
                <div class="col-md-1">
                </div>
                <div class="col-md-2">
                </div>
                <div class="col-md-3 pd-10 text-center">
                    <a class="btn btn-primary" name="createzip" id="createzip" value="createzip"> DOWNLOAD ALL </a>
                </div>
            </tr>
            <tr>
                <th class="table-plus datatable-nosort"> <input id="select_all" style="max-height: 20px; max-width: 20px;" type="checkbox" class="form-control" value="Select All"/> <p> Select All </p></th>
                <th> COMPANY NAME </th>
                <th> EMPLOYEE NAME </th>
                <th> DOWNLOAD LINK </th>
            </tr>
        </thead>
        <tbody>
            <tr>

                <?php
                
                    $sql = "SELECT * FROM vouchers WHERE voucher_id BETWEEN '$empID' AND '$endEmpID'";
                    $query = mysqli_query($conn, $sql) or die(mysqli_error());
                    while ($row = mysqli_fetch_array($query)) {
                    $id = $row['voucher_id'];
                 ?>  

                <td class="table-plus">
                    <input style="max-height: 20px; max-width: 20px;" name="fieldid[]" id="checkbox<?php echo $row['voucher_id'] ?>" value="<?php $row['voucher_id'] ?>" type="checkbox" class="form-control">
                </td>
                <td><?php echo $row['paid_by']; ?></td>
                <td><?php echo $row['paid_by']; ?></td>
                <td><a href="print_voucher.php?em_id=<?php echo $row['voucher_id'] ?>" download="print_voucher.php?em_id=<?php echo $row['voucher_id'] ?>"> Download </a></td>

            </tr>
            <?php }?>
        </tbody>
    </table>
</form>

How to download the files simultaneously?

Answer 1

You can do it with jquery/js when click button. Firstly, you need to add download button to the html tags

<button class='download'> Download files </button>

After it, add the below codes to the script tag at end of the file :

$('.download_button').click(function(e) {
    e.preventDefault();

    $('.table-plus input:checked').each(function (e){
        window.open('http://yoursite.com/print_voucher.php?em_id='+this.value);
    });
});

Additionally, if you want to download any files also PDF, you will need to change server headers for download files like that (it is server side - PHP read example):

<?php
header("Content-type:application/pdf");

// It will be called downloaded.pdf
header("Content-Disposition:attachment;filename='myFile.pdf'");

readfile("myFile.pdf");