Using Gravity Forms ‘gform_coupons_is_valid_code’ PHP filter

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The gform_coupons_is_valid_code filter allows you to override the default alphanumeric validation check for coupon codes in Gravity Forms.

Usage

To use this filter, add the following code to your functions.php file:

add_filter('gform_coupons_is_valid_code', 'your_function_name', 10, 2);

Parameters

  • $is_alphanumeric (bool): Indicates if the coupon code is alphanumeric.
  • $field (Field Object): The field object representing the coupon code field.

More information

See Gravity Forms Docs: gform_coupons_is_valid_code

Examples

Mark all coupon codes as valid

This example marks all coupon codes as valid, regardless of whether they are alphanumeric or not.

add_filter('gform_coupons_is_valid_code', 'mark_coupon_valid', 10, 2);

function mark_coupon_valid($alphanumeric, $field) {
    return true;
}

Only allow numeric coupon codes

This example only allows coupon codes containing numbers.

add_filter('gform_coupons_is_valid_code', 'allow_only_numeric', 10, 2);

function allow_only_numeric($alphanumeric, $field) {
    return ctype_digit($field->value);
}

Allow coupon codes with specific prefixes

This example allows coupon codes with specific prefixes (e.g., ‘PRE-‘, ‘SPECIAL-‘).

add_filter('gform_coupons_is_valid_code', 'allow_specific_prefixes', 10, 2);

function allow_specific_prefixes($alphanumeric, $field) {
    $prefixes = array('PRE-', 'SPECIAL-');
    foreach ($prefixes as $prefix) {
        if (substr($field->value, 0, strlen($prefix)) === $prefix) {
            return true;
        }
    }
    return false;
}

Allow specific coupon codes

This example allows only specific coupon codes.

add_filter('gform_coupons_is_valid_code', 'allow_specific_codes', 10, 2);

function allow_specific_codes($alphanumeric, $field) {
    $allowed_codes = array('SAVE10', 'FREESHIP', 'EARLYBIRD');
    return in_array($field->value, $allowed_codes);
}

Custom alphanumeric validation

This example uses a custom alphanumeric validation that allows spaces and dashes.

add_filter('gform_coupons_is_valid_code', 'custom_alphanumeric_validation', 10, 2);

function custom_alphanumeric_validation($alphanumeric, $field) {
    return preg_match('/^[a-zA-Z0-9 -]+$/', $field->value);
}