Which methods are automatically called on certain events in Yii2?

In Yii2, there are several methods that are called automatically during certain lifecycle events of a model or component. The main ones are:

• init() — called after object creation, used for initialization.
• beforeValidate() and afterValidate() — called before and after model validation.
• beforeSave($insert) and afterSave($insert, $changedAttributes) — called before and after saving the model to the database. The $insert parameter indicates whether a new record is being created.
• beforeDelete() and afterDelete() — called before and after deleting the model.
• afterFind() — called after loading the model from the database.

Additionally, Yii2 uses an event system where you can subscribe to events and execute code when they occur.

Example of overriding a method:

class Post extends \yii\db\ActiveRecord
{
    public function beforeSave($insert)
    {
        if (!parent::beforeSave($insert)) {
            return false;
        }
        // additional logic before saving
        return true;
    }
}

Thus, these methods allow you to inject logic at key stages of working with models.