Reply To: Minimum number of characters in a text field

• Jeremy Varnham

• June 28, 2014 at 8:02 pm

As the ACF GUI only gives the option for a maximum character limit, you can use the acf/validate_value filter along with the PHP: strlen function to count the number of characters. I would also add a note under Field Instructions so the user knows the limit before submitting.

Assuming you want a minimum of ten characters:

add_filter('acf/validate_value/name=validate_this_image', 'my_acf_validate_value', 10, 4);
 
function my_acf_validate_value( $valid, $value, $field, $input ){
 
	// bail early if value is already invalid
	if( !$valid ) {
 
		return $valid;
 
	}
 
 
	// load data
	
	$my_text_field = get_field('text_field');
	
	if ( strlen($my_text_field) < 10 ) {
		
		$valid = 'Must be a minimum of 10 characters.';
	} 
	
 
	// return
	return $valid;
 
}