Using Gravity Forms gform_field_validation for Full Name to check for first and last name

Question

I want to use the gform_field_validation function from Gravity Forms to validate a Full Name field only if there's a space between the two names, validating that someone didn't just put in one name, and put it a first and last name.

I believe I've found the correct Regex to do it /^[a-zA-Z ]+$/ . Just don't know how to implement it.

Answer 1

Try this:

add_filter( 'gform_field_validation', 'validate_fullname', 10, 4 );
function validate_fullname( $result, $value, $form, $field ) {
    $pattern = "/^\w+\s\w+$/";
    if ( ! preg_match( $pattern, $value ) ) {
        $result['is_valid'] = false;
        $result['message']  = 'Please enter a valid full name';
    } else {
        $result['is_valid'] = true;
        $result['message']  = '';
    }
 
    return $result;
}

Explanation:

• ^ - anchor at start of string
• \w+ - 1+ word characters
• \s - a single space
• \w+ - 1+ word characters
• $ - anchor at end of string

You might want a more forgiving regex allowing with multiple words:

    $pattern = "/^\w+(\s\w+)+$/";

Explanation:

• (\s\w+)+ - one or more sequences of space followed by word chars