make button disabled based on if row column - php

Question

I have some working PHP code and I have recently added a button that allows the user to download the image form the root directory, in the database we put the file name e.g. example.png / example.jpeg and when the user clicks download it opens the image in a new tab
what we need is: if the [proof] is= NULL , the download button disables, otherwise it will be enabled and they can click the button
<?php
// output data of each row
while($row=mysqli_fetch_assoc($designresult)) {
?>
<div class="card mb-4 box-shadow"><div class="card-header">
<h4 class="my-0 font-weight-normal">Job Reference: <?php echo $row["jobRef"]; ?></h4>
</div>
<div class="card-body">
<p><b>Company Name:</b><br> <?php echo $row["companyName"]; ?> </p>
<p><b>Requested:</b><br> <?php echo $row["dateReq"]; ?> </p>
<p><b>Request By:</b><br> <?php echo $row["yourName"]; ?> </p>
<p><b>Graphic Type:</b><br> <?php echo $row["graphicType"]; ?> </p>
<p><b>Double Sided:</b><br> <?php echo $row["doubleS"]; ?> </p>
<p><b>Design Info:</b><br> <?php echo $row["info"]; ?> </p>
<p><b>Purpose:</b><br> <?php echo $row["purpose"]; ?> </p>
<p><b>Proof:</b><br> <?php echo $row["approved"]; ?> </p>
<p><b>Proof Date:</b><br> <?php echo $row["appDate"]; ?> </p>
<a class="btn btn-success" target="_blank" href="<?php echo IMAGE_DIR . $row['proof']; ?>">Download</a>
</div>
</div>
<?php
}
?>

Answer 1

To my knowledge the link tag does not have a "disabled" attribute. But you can "disable" the link by removing the href attribute.
Something like this: It checks if $row['proof'] has some value (by negating the empty), then it prints out the href if result is true.
<a class="btn btn-success" target="_blank" <?php if(!empty($row['proof'])): ?> href="<?php echo IMAGE_DIR . $row['proof']; ?>" <?php endif; ?> >Download</a>
Or maybe better: Check if variable is empty and give the user a hint that it's not available. I think this is the better solution, because then your users will know what's going on.
<?php if(empty($row['proof'])): ?>
<span>No proof available</span>
<?php else: ?>
<a class="btn btn-success" target="_blank" href="<?php echo IMAGE_DIR . $row['proof']; ?>">
Download
</a>
<?php endif; ?>

Answer 2

<a
class="btn btn-success"
target="_blank"
<?php if(empty($row['proof'])) echo "disabled"; ?>
href="<?php if(!empty($row['proof'])) echo IMAGE_DIR . $row['proof']; ?>">
Download
</a>
try above code. and add disabled class using this condition

Answer 3

<?php
$state = (empty($row['proof'])) ? "disabled='disabled'" : "";
$class = (empty($row['proof'])) ? "disabled" : "";
?>
<a class="btn btn-success <?php echo $class; ?>" target="_blank" href="<?php echo IMAGE_DIR . $row['proof']; ?>" <?php echo $state; ?>>Download</a>
To disabled the button, you need to use disabled HTML attribute. The code above checks $row['proof'] == NULL. If this statement is true it prints disabled = "disabled" in the button element and it isn't true, it prints nothing.
Assuming that you are using bootstrap, .disabled will grayed out the button.