I found a strange bug today. Take a look at this:

piklist('field', array(
	'type'		=> 'number',
	'field'		=> 'price',
	'label'		=> __('Price ($)'),
	'attributes'=> array(
		'placeholder'		=> 'Free',
		'pattern'		=> '[0-9]+([\,|\.][0-9]+)?',
		'step'			=> 0.01,
		'min'			=> 0
	)
));

So I’m using the number field, which applies a default value of 1 to the step and min attributes. This works fine. But, if I change the min attribute, as I’m doing above, if actually removes the attribute from the element. I’ve checked the inspector. If I remove the ‘min’ => 0 line, it has a min of 1; if I leave it, there’s no min.

After a brief digging, I found line 1741 in class-piklist-form and changed it to the following:

if (isset($value) && ($value !== '') && !in_array($key, $exclude))

That made sure it’s not an empty string (which would produce a “=value”), it’s set, and it’s not null. Otherwise it didn’t accept a value of 0.

Hope this helps!