[RESOLVED] die; or not

GrexP

This one is pretty basic, I'm sure. What is the best way to bail out of a script or stop processing a page completely? If I have a series of if{} blocks to check criteria of data and I want to completely exit the script (page) and stop processing anything do I just call die; or is there a better way.

	if ($FName != $TestName){
         	echo "The file name must be the patients ID number with a 'zip' extention ({$TestName}).\n";
		die;
	}

NogDog

die or exit will certainly terminate the script at that point, and that's what they are designed to do. The real question here, I think, is whether you actually want to flat out terminate at that point, or do something more "graceful". If you die, nothing else will be output, which may mean you end up outputting invalid [X]HTML. Or the user may not see any output at all, which is certainly not user friendly.

A pattern I sometimes use is something like:

$errors = array();
if(trim($_POST['name']) === '')
{
   $errors[] = "Name is required.";
}
if(trim($_POST['password']) === '')
{
   $errors[] = "Password is required.";
}
if(count($errors))
{
   echo "<p class='error'>" . implode("<br />\n", $errors) . "</p>\n";
}
else
{
   // process the form data here and output result
}

GrexP

Nice. I like the use of the self made errors() array. The die; command has always seemed ineloquent, at best. So, die; doesn't do any clean-up at all. It is the equivalent of Exit Sub (vb) or return (C). If I do use it, I would need to make sure I close any open tags. Is that correct?

NogDog

Yes, you could do that, too, if it make sense for your program flow.

One place I do use die/exit is after a header() redirect to ensure nothing else is processed:

<?php
if($some_condition)
{
   header('Location: http://example.com/index.php');
   exit;
}
?><html>
<!-- etc.... -->
</html>

GrexP

Good point. Thanks.