I have tested this item ✅ successfully on ecb7260

I have tested this item ✅ successfully on ecb7260

Not able to reproduce with v3.9.15.

Strange, I am able to reproduce with v3.9.15 today.

Sorry false alarm. I had applied your PR when testing. Duh! To me, it feels hackish fix.

You are right, this is hackish!
It would be more correct to change empty() to isset().

The problem is that emty("0") is interpreted as "there is no default value". Even "0" as a string! That is not correct. There is a default value in our case!

Do you like my new version better?

Now it is always invalid.

@Quy The last change is embarrassing to me.

Now it should fit.

The following things are considered to be empty (https://www.php.net/empty):

• "" (an empty string)
• 0 (0 as an integer)
• 0.0 (0 as a float)
• "0" (0 as a string)
• NULL
• FALSE
• array() (an empty array)
  and
• var $var; (a variable declared, but without a value in a class)

If I am correct, we have to treat the case string "0" differently.

@N6REJ I would be happy if you could test again

Requested updates are done.

I have tested this item ✅ successfully on 8a61ac9

Having a closer look, integer 0 and float 0.0 should also pass. So it would probably be better to compare against actually empty values (null, empty string and maybe empty array) rather than do empty() check. And we might need this for other validation rules as well.

@SharkyKZ Having a closer look, integer 0 and float 0.0 should also pass. So it would probably be better to compare against actually empty values (null, empty string and maybe empty array) rather than do empty() check.

I hope I understand you correctly. 0.0 does not pass as we use it as a string.

Do you mean this?

@SharkyKZ And we might need this for other validation rules as well.

You're right. If I find a solution here that is good, I would look at more. I think it makes this PR more complicated if I try to includ this here.

This issue affects core form validation rules, so not just custom fields but any forms using them.

@SharkyKZ I do not understand what you mean. I know that this rule does not just apply to custom fields.
I prevent a string '0' from being considered as no default value. In my opinion, this is also correct in the core. Don't you see it that way? Can you give me an example of where this is wrong.

I haven't tested it but what's about is_numeric ?
https://www.php.net/manual/en/function.is-numeric.php

$tests = array(
-0,
0,
0.0,
.0,
'-0',
'0',
'0.0',
'.0',
'',
null
);

foreach ($tests as $element) {
 if (is_numeric($element)) {
  echo gettype($element)  . ':', PHP_EOL;
  echo var_export($element, true) . " is numeric" . PHP_EOL;
 } else {
  echo gettype($element)  . ':', PHP_EOL;
  echo var_export($element, true) . " is NOT numeric", PHP_EOL;
 }
}
exit;

integer:
0 is numeric
integer:
0 is numeric
double:
0.0 is numeric
double:
0.0 is numeric
string:
'-0' is numeric
string:
'0' is numeric
string:
'0.0' is numeric
string:
'.0' is numeric
string:
'' is NOT numeric
NULL:
NULL is NOT numeric

if (empty($val) && !is_numeric($val))
{
 --- DO sth. ---
}

OK. Now I saw it. $value is of type mixed - although I cannot find a place for thus OptionsRule that contains anything other than string.

But I think we can use the empty() function to make it easier. I just updated the branch.

What do you all mean?

This doesn't cover negative values. If you want to keep logic this way, use is_numeric() like suggested by @ReLater.

What is not covered?
Signed 0 (-0) is in PHP equal to not signed 0 for float and int: https://stackoverflow.com/questions/31250241/is-minus-negative-zero-equivalent-to-0-in-php?answertab=votes#tab-top
Am I missing something?

No, you're right. My bad. This works fine.

This test is irrelevant! My fault.

I have tested this item ? unsuccessfully on 3ccf188

Tested like instructed with today's nightly.

Radio Value: 1 => 1

Default Values:
0
0.0
.0
-0

"Save failed with the following error: The default value is invalid."

I have tested this item ✅ successfully on 3ccf188

Ah sorry. There shall be the error if 0 entered as default value.

I have tested this item ✅ successfully on 3ccf188

RTC

Thanks