In WordPress development, there may be times when you need to validate the input of Advanced Custom Fields (ACF) before saving it to the database. However, you might encounter situations where the ACF field validation is not working as expected. This can be frustrating, but there are a few steps you can take to troubleshoot and resolve the issue.
First, make sure you have properly set up the ACF field validation rules. You can define validation rules for ACF fields using the acf/validate_value filter. Here’s an example code snippet that demonstrates how to add a validation rule to check if a text field is not empty:
function wpsnippets_validate_text_field( $valid, $value, $field, $input_name ) {
if ( empty( $value ) ) {
$valid = 'This field is required.';
}
return $valid;
}
add_filter( 'acf/validate_value/type=text', 'wpsnippets_validate_text_field', 10, 4 );
In the code snippet above, we define a custom validation function wpsnippets_validate_text_field that accepts four parameters: $valid, $value, $field, and $input_name. The function checks if the $value is empty and sets the $valid variable to an error message if it is. Finally, we return the $valid variable.
To use this code snippet, you need to replace text with the ACF field type you want to validate. You can add this code to your theme’s functions.php file or a custom plugin.
If the ACF field validation is still not working after implementing the above code, there might be a conflict with other plugins or custom code. In such cases, you can try disabling other plugins one by one to identify any conflicts. Additionally, check if there are any JavaScript errors in the browser console that might be preventing the validation from working correctly.
Remember to always test your code thoroughly after making any changes to ensure the ACF field validation is working as expected.
Examples
Example #1: ACF field validation not working with custom PHP function
This example demonstrates how to use a custom PHP function to validate an ACF field and display an error message if the validation fails.
function wpsnippets_validate_acf_field( $value, $field, $input ) {
if ( empty( $value ) ) {
$input['valid'] = false;
$input['message'] = 'This field is required.';
}
return $input;
}
add_filter( 'acf/validate_value', 'wpsnippets_validate_acf_field', 10, 3 );
In this code example, we define a custom PHP function wpsnippets_validate_acf_field that takes three parameters: $value, $field, and $input. Inside the function, we check if the $value is empty, and if so, we set $input['valid'] to false and $input['message'] to the error message we want to display. Finally, we return the modified $input array.
We then use the add_filter function to hook our custom validation function into the acf/validate_value filter, which is triggered when ACF validates a field value. This ensures that our custom validation function is called during the validation process.
Example #2: ACF field validation not working with JavaScript
This example demonstrates how to use JavaScript to validate an ACF field and display an error message if the validation fails.
(function($) {
$(document).on('acf/validate_field', function(e, field) {
var $field = $(field),
$input = $field.find('input[type="text"]'),
value = $input.val();
if (value === '') {
acf.validation.add_error($input, 'This field is required.');
}
});
})(jQuery);
In this code example, we use JavaScript to listen for the acf/validate_field event, which is triggered when ACF validates a field. Inside the event handler, we retrieve the field element and the input element within it. We then check if the input value is empty, and if so, we use the acf.validation.add_error function to display an error message below the input.
Note that this code should be placed within a JavaScript file that is enqueued on the page where the ACF form is displayed.
Example #3: ACF field validation not working with conditional logic
This example demonstrates how to use ACF’s conditional logic to validate an ACF field based on the value of another field.
function wpsnippets_validate_acf_field( $value, $field, $input ) {
$other_field_value = get_field( 'other_field' );
if ( $other_field_value === 'some_value' && empty( $value ) ) {
$input['valid'] = false;
$input['message'] = 'This field is required when the other field has a certain value.';
}
return $input;
}
add_filter( 'acf/validate_value', 'wpsnippets_validate_acf_field', 10, 3 );
In this code example, we retrieve the value of another ACF field using the get_field function and store it in the $other_field_value variable. We then check if the $other_field_value is equal to 'some_value' and if the current field value is empty. If both conditions are met, we set $input['valid'] to false and $input['message'] to the error message we want to display.
By using conditional logic in our validation function, we can create more complex validation rules based on the values of other fields in the ACF form.