Keeping a variable from one function to the next

Jsn7821

function form_error($error) {
	if (!isset($error_count)) {
	global $error_count;
	$error_count = 1; 
	}
	if ($error_count == 1) { echo "<strong>Error:</strong><br />\n"; }
	echo $error_count.': '.$error."<br /><br />\n";
	$error_count++;
}

This function simply formats form input errors and counts them. Except it doesn't do the counting part.... each time the function is called, it seems that $error_count disapears and it creates it again. I'm confused by this, because I thought variables stayed around from function to function.

On a side note: is this a very efficient way of handling form errors? I have it check a whole bunch of things, report the errors, then if $error_count == 0 the form goes though. This system works, but it seems like there should be a better one.

Primordial

Hi Jsn,

Not totally sute about the benefit of the function but it appears you are 'globalising' the variable error_count before you have defined it.

Just a thought 🙂

Cheers, Primordial

laserlight

You might be looking to use the static keyword instead of the global keyword.

function form_error($error) {
	static $error_count = 0;
	$error_count++;
	echo "<strong>Error:</strong><br />\n" . $error_count . ": "
		. $error . "<br /><br />\n";
}

brownerg

Thats assuming its PHP5...

Are you declaring the variable ouside the function as well?

laserlight

Thats assuming its PHP5...

If you're talking about the use of static, the static keyword may be used in PHP4 as well.

maxpup979

And if you arent using PHP5, what you can do is set the variable outside the scope of the function, and globalize it inside the function....
$error_count=1;
form_error();

 function form_error($error) {
    if (!isset($error_count)) {
    global $error_count;
    }
    if ($error_count == 1) { echo "<strong>Error:</strong><br />\n"; }
    echo $error_count.': '.$error."<br /><br />\n";
    $error_count++;
}

Jsn7821

Alright it works now, but im still not sure this is the appropreate way to do what im doing. A form is submitted, then my script checks for blank fields. If there are blank fields, form_error('Please make sure all fields are filled out'); and it goes on checking a number of different things in that same format. Then it uses $error_count to see if the page should be displayed.

I did it this way because I didnt want a huge tree of if/else statements. What are some other ways to verify form information?

laserlight

Then it uses $error_count to see if the page should be displayed.

If that is the case, then you are not interested in how many errors there were, only in whether or not there was at least one error. Realistically, you are not going to check for blank fields alone - even if the fields are filled you would validate them, and invalid but filled fields are still errors.

Consider a form that takes in a name and an age. You might be willing to let the user enter numbers in addition to letters and spaces for the name, or even exclamation marks (think Kalahari desert people), so there you might only check that the field is not empty. But surely the age will be filled with a non-negative integer (you dont expect people to calculate their age to the second and express in years, after all).

A possible error checking snippet might be:

//check for form data entry errors
$errors = array();
//form should be submitted via POST method
if (empty($_POST['name'])) {
	$errors[] = 'Name not specified';
}
if (empty($_POST['age']) || !ctype_digit($_POST['age']) || $_$POST['age'] < 0) {
	$errors[] = 'Age not specified, or invalid';
}

//are there any form data entry errors?
if (($error_count = count($errors)) == 0) {
	//process the form
} else {
	//print the form data entry errors
	echo "Error:<br />\n";
	for ($i = 0; $i < $error_count; $i++) {
		echo $error[$i] . "<br />\n";
	}
}