Laravel self-validating model. Child models need only extend `getRules()` and return their own rules array. Loosely based on Jeffrey Way's (https://tutsplus.com/lesson/validating-with-models-and-event-listeners/).

ValidatingModel.php

<?php

abstract class ValidatingModel extends \Eloquent
{
    public $errors;

    public static function boot()
    {
        parent::boot();

        static::saving(
            function ($model) {
                return $model->validate();
            }
        );
    }

    public function validate()
    {
        $validation = \Validator::make($this->attributes, $this->getRules());

        if ($validation->passes()) {
            return true;
        }

        $this->errors = $validation->messages();
        return false;
    }

    abstract protected function getRules();
}