WP_Model-advanced-exmaple.php

<?php

Class Data extends WP_Model{

    public $postType = 'data';

    public $attributes = [
        'foo',
        'author',
    ];

    public $filter = [
        'author'
    ];

    public function _filterAuthor(){
        return get_user_by('ID', $this->author);
    }

    public function inserting(){
        $this->author = get_current_user_id();
    }
}
Data::register();


$data = new Data
$data->foo = 'bar';
$data->save();

$data = Data::find(1);
$data->author; // WP_User