Writing custom rules for CakePHP model - cakephp

Question

use App\Model\Rule\CustomIsUnique;
$rules->add(new CustomIsUnique(['item_id', 'manufacture_unit_id']), [
'errorField' => 'item_id',
'message' => 'Item Unit must be unique.'
]);
On CustomIsUnique I've copy pasted codes of IsUnique
Cake\ORM\Rule\IsUnique;
But How to extend or add more operations inside the __invoke method ?
Update ::
public function __invoke(EntityInterface $entity, array $options)
{
$result = parent::__invoke($entity, $options);
if ($result) {
return true;
} else {
if ($options['type'] == 'item_units') {
$data = TableRegistry::get('item_units')->find()
->where(['item_id' => $entity['item_id'],
'manufacture_unit_id' => $entity['manufacture_unit_id'],
'status !=' => 99])->hydrate(false)->first();
if (empty($data)) {
return true;
}
} elseif ($options['type'] == 'production_rules') {
$data = TableRegistry::get('production_rules')->find()
->where(['input_item_id' => $entity['input_item_id'],
'output_item_id' => $entity['output_item_id'],
'status !=' => 99])->hydrate(false)->first();
if (empty($data)) {
return true;
}
} elseif ($options['type'] == 'prices') {
$data = TableRegistry::get('prices')->find()
->where(['item_id' => $entity['item_id'],
'manufacture_unit_id' => $entity['manufacture_unit_id'],
'status !=' => 99])->hydrate(false)->first();
if (empty($data)) {
return true;
}
}
}
}
this is how I've implemented for different model and passed extra parameter along with options array. I think this is not the good way to do this.

Answer 1

If you want to extend a core application rule, you can do something like:
<?php
use App\Model\Rule;
class CustomIsUnique extends Cake\ORM\Rule\IsUnique
{
public function __invoke(EntityInterface $entity, array $options)
{
$result = parent::__invoke($entity, $options);
if ($result) {
// the record is indeed unique
return true;
}
// do any other checking here
// for instance, checking if the existing record
// has a different deletion status than the one
// you are inserting
}
}
That will let you add any additional logic for your application.