Display confirmation message - php

Question

I need to get confirmation before proceeding.
My code is:
echo "<SCRIPT> confirm('Are you sure you want to continue') </SCRIPT>";
//press ok should keep on processing the code while cancel not.
Currently any button pressed continues.
How can I validate what button in the confirmation pop up window is pressed?

Answer 1

You cannot.
PHP is a server-side language and JavaScript is a slient-side one.
PHP is executed on server long before JavaScript starts to execute in the clients browser.
One way to do that is to split the service in two. You don't even have to use JavaScript confirm, you can just use HTML form with submit button and a hidden value with POST method.
<form method="POST">
<input type=hidden name="internal_check" value="42">
<input type=submit value="Click me to confirm!">
</form>
After clicking the button the page will be reloaded.
In the PHP script you can check POST variables for that value and if present you can continue doing the comfirmed job using something like this:
<?php
if(isset($_POST['internal_check']) && $_POST['internal_check'] == 42)
{
/* do confimed job here */
}
else
{
?>
<form method="POST">
<input type=hidden name="internal_check" value="42">
<input type=submit value="Click me to confirm!">
</form>
<?php
}
?>
If the page was not accessed via POST call with the secret variable holding the right value the user will only see the confirmation form. Otherwise the special code will be executed.
If you are not happy with reloading the page the same may be done using AJAX. The basics are the same, but it is a bit more complicated.