foreach() failure

[srg]

PHP Version 4.3.3RC1

If $status goes false then foreach() breaks!

	foreach( $a_validation as $key => $value )
	{
		$status = $status && validate_field( $key, $value );
		//$status = false;	// Testing!!! Does foreach() choke on this? YES!!!
	}

[Weedpacket]

Works for me. More detail needed.
(PS: look up the [man]break[/man] statement in the manual; it will cut the average time the loop takes by 50%.)

[srg]

a little more detail ...
The idea is validate all fields (print error messages) and have 1 summary status.

PHP Version 4.3.3RC1

function validate_field( $field_name, $field_parameters )
{

...
}

function validate_fields()
{
	global $a_validation;
	$status = true;

	foreach( $a_validation as $key => $value )
	{
		$status = $status && validate_field( $key, $value );
		//$status = false;	// Testing!!! Does foreach() choke on this? YES!!!
	}

	return $status;
}

...
if( !validate_fields() )
exit( "<br>Please go back and fix these errors." );

[ahundiak]

Not really sure what you mean by choking but use:

foreach( $a_validation as $key => $value ) 
{
  if (!validate_field($key,$value)) return false;
}

No real need for a status.

[srg]

Wrong!
That will stop on/after the first error.
I want to validate ALL of the fields and print ALL of the error messages.
You can see it on my server:
http://gsdtest.t35.com:8000/clients/armny.com/ge_form.php

First, fill in all the fields and submit.
Then, blank Address1 and submit.

Steven

[ahundiak]

Fair enough. Then just use:

if (!validate_field($key,$value)) $status = false;

I'd still like to know what you mean when you say the setting $status to false chokes the foreach loop.

[srg]

OK
I'm trying to be clear. Did you check my website?

Before entering the foreach() loop $status is set to true.
In the loop: $status = $status && validate_field( $key, $value )
true && true --> true
false && true --> false
true && false --> false
false && false --> false
After exiting the loop $status will be false if any of the fields failed validation.
Of course, $status will true if ALL of the fields passed validation.

The foreach() loop SHOULD cycle through each and every element of the array. It does this correctly when $status remains true (ALL fields passed validation). But when $status becomes false the loop breaks prematurely!
I believe that this is a bug in PHP Version 4.3.3RC1

Steven

[ahundiak]

Yikes. Remind me not to try that development version.

I take it that you are sure that validate_field is not somehow accessing $a_validation?

[HalfaBee]

Your link is broken 🙁

I doubt if it is a bug in PHP.

HalfaBee

[srg]

Sorry,
It looks like a server crash.

Steven

[srg]

My server is up again.

Steven

[HalfaBee]

How about access to the required file.
I would like to test this on my server to try and see what the problem is.

HalfaBee

[Weedpacket]

It is looking like a PHP bug to me; the only reason why the foreach() would abort is if something happened to $a_validation in the meantime; $a_validation isn't even looked at in the only function called within the loop, and there are no references floating around (especially if the $status=false line is used).

If it is a PHP bug, then it might help to boil the problem down to a test script that's small and simple enough for anyone to understand and run which still displays the behaviour, then forward it on to the developers. That would see it addressed when 4.3.3 is released. In the meantime, use the current stable version.

[HalfaBee]

Sure looks like a bug.

I tried this

<?
function status( $c )
{
    echo $c;
 if( $c == 'two' )
 return FALSE;
 return TRUE;
}

$a = array( 'one','two','three','four' );
$status = TRUE;
foreach( $a as $b )
{
 $status  = $status && status( $b );
}
?>

and it stops at 'two'.

If you change it to
$status &= status( $b );

It works fine.

HalfaBee

[HalfaBee]

It is not a bug.

It is boolean shortcuts that are happening.
When $status is FALSE the expression is implicitly false so the function is not executed.

That is why the &= works correctly.

HalfaBee

[ahundiak]

I don't know. srg was pretty insistent on the notion that the line "status = false" was causing foreach to "choke". I tried giving him (her?) correct code by it didn't do much good.

[srg]

Sorry!
I finally found it in the PHP bug list.
It is NOT a bug!
PHP is smarter than I thought: it is doing a short-circuit evaluation.
http://bugs.php.net/bug.php?id=24626
I love this language!

Thanks,
Steven

PS. Thanks HalfaBee