#Advanced Validation
Define custom validation rules and error messages based on the current screen location in the field’s UI. In order to enable the Advanced Validation UI, you must enable the Field Group: Advanced Settings feature.
- Order
- Label
- Name
- Key
- Type
- My Field
- my_field
- Text
#Available Locations
Choose the location screen where the validation rule should be applied. You can set multiple rules groups based on different locations.
- Everywhere
- Administration
- Front-end
#Available Functions
The UI comes with predefined functions that can be used out of the box.
| Function name | PHP Function |
| If value | if($value) |
| If value length | if(strlen($value)) |
| If count value | if(count($value)) |
| If email exists | if(email_exists($value)) |
| If post type exists | if(post_type_exists($value)) |
| If taxonomy exists | if(taxonomy_exists($value)) |
| If term exists | if(term_exists($value)) |
| If username exists | if(username_exists($value)) |
| If is email | if(is_email($value)) |
| If is user logged in | if(is_user_logged_in()) |
| If is array | if(is_array($value)) |
| If is string | if(is_string($value)) |
| If is numeric | if(is_numeric($value)) |
| If get post type | if(get_post_type($value)) |
| If post id exists | if(get_post_by_id($value)) |
| If post slug exists | if(get_post_by_slug($value)) |
| If post title exists | if(get_post_by_title($value)) |
| If sanitize email | if(sanitize_email($value)) |
| If sanitize file name | if(sanitize_file_name($value)) |
| If sanitize html class | if(sanitize_html_class($value)) |
| If sanitize key | if(sanitize_key($value)) |
| If sanitize meta | if(sanitize_meta($value)) |
| If sanitize mime type | if(sanitize_mime_type($value)) |
| If sanitize option | if(sanitize_option($value)) |
| If sanitize text field | if(sanitize_text_field($value)) |
| If sanitize title | if(sanitize_title($value)) |
| If sanitize user | if(sanitize_user($value)) |
| If get user by id | if(get_user_by('id', $value)) |
| If get user by slug | if(get_user_by('slug', $value)) |
| If get user by email | if(get_user_by('email', $value)) |
| If get user by login | if(get_user_by('login', $value)) |
#Available Operators
The UI comes with predefined operators that can be used out of the box.
| operator |
| == |
| != |
| > |
| >= |
| < |
| <= |
| Contains |
| Doesn’t contain |
| Starts with |
| Doesn’t start with |
| Ends with |
| Doesn’t end with |
| Matches regex |
| Doesn’t match regex |
| == true |
| != true |
| == false |
| != false |
| == null |
| != null |
| == “” (empty) |
| != “” (empty) |
#Set Validation Rules in PHP
It is possible to add validation rules based on the screen location programmatically using the acf/validate_value hook combined with acfe_is_admin() and acfe_is_front() functions.
Note that this method doesn’t require to enable the “Advanced Settings” in the field group as it is directly executed in PHP. See ACF documentation. Usage example:
/**
* https://www.advancedcustomfields.com/resources/acf-validate_value/
*/
add_filter('acf/validate_value/name=my_field', 'my_acf_validate_my_field', 10, 4);
function my_acf_validate_my_field($valid, $value, $field, $input){
// admin only
if(acfe_is_admin()){
if(strlen($value) > 10){
$valid = 'The value should contain less than 10 characters';
}
}
// front-end only
if(acfe_is_front()){
if(strlen($value) > 30){
$valid = 'The value should contain less than 30 characters';
}
}
// return
return $valid;
}
