Phalcon virtual field which is not defined in map

Hello everyone,

I've read carefully information about virtual fields on this forum. What do I need:

I have some translations for model in separated table. I would like to attach them as a virtual field via trait to the model.

Example: Table & Model: category ($id, $systemName) Table: category_translation ($parentId related to category.id, $locale, $name)

So category hasMany category_translation records (1 row per 1 locale). So after some manipulations, I have an array

$locales = [ 'en' => 'value', 'tr' => 'other_value', 'es' => 'es value', ... ];

Now I would like to attach this array to category model on fetch.

public function afterFetch() { $this->locales = $this->methodThatReturnsAnArray(); }

But it doesn't work, because locales column is not exists in table. Option is to create an empty unused field in table, but this is definitely not a right way.

What is a best option to add a virtual unexisting in table column to model mapping?

Would not you be calculating the same thing many times? I mean, why do not you just add this method to your model?