acf_add_validation_error() │ ACF 5.0.0

Adds a validation error and prevents submitted ACF form data from being saved.

No Hooks.

Returns

n/a. Nothing. Stops the data-saving process.

Usage

acf_add_validation_error( $input, $message );

$input (required)

The value of the name attribute of the field for which to display an error. The format is acf[field key], for example acf[field_615baebe3f16d]. JavaScript uses this value to find the field.

If an empty string is passed, the error applies to the general error and is displayed above the submitted form.

$message

The error message, for example Chief, everything is lost! Everything is lost!.
Default: ''

Examples

#1 Check a field and display an error

add_action('acf/validate_save_post', 'my_acf_validate_save_post');
function my_acf_validate_save_post() {

	// Remove all errors for the administrator (remove this code if not needed).
	if( current_user_can('manage_options') ) {
		acf_reset_validation_errors();
	}

	// Make the field required.
	if( empty($_POST['acf']['field_615baebe3f16d']) ) {
		acf_add_validation_error( 'acf[field_615baebe3f16d]', 'Fill in this field!' );
	}
}

#2 Returned data

Example returned data for a single field:

{
	"success": true,
	"data": {
		"valid": 0,
		"errors": [
			{
				"input": "acf[field_615baebe3f16d]",
				"message": "This price is too low for this type of work."
			}
		]
	}
}

Example returned data for a general error:

{
	"success": true,
	"data": {
		"valid": 0,
		"errors": [
			{
				"input": "",
				"message": "You must specify a shipping price for at least one vehicle type: \"Passenger car\", \"SUV\", or \"Minibus\"."
			}
		]
	}
}