Какова последовательность валидаторов в Yii2?

public function rules()
{
    return [
        [['access', 'active', 'published'], 'integer'],
        [['about'], 'string'],
        ...
        ...
        ...
        ...
        ...
        ...
        ...
        [['about'], 'checkEmpty'],
        [['published'], 'checkConditionsPublished'],
        [['access'], 'checkConditionsAccess'],
        [['active'], 'checkConditionsActive'],
    ];
}
public function checkConditionsAccess($attribute){ //echo 'access'; exit;
    if (Yii::$app->user->identity->access != 1){
        if ($this->$attribute != $this->getOldAttribute($attribute)){
            $this->addError($attribute, 'Permission denied! You can\'t change your access!');
        }
    }
    elseif ($this->access == 1){
        if ($this->published == ''){
            $this->addError($attribute, 'To set user  as "Admin" or "Writer" first you must set field "Published"!');
        }
    }
}
public function checkConditionsActive($attribute){ //echo 'active'; exit;
    if (Yii::$app->user->identity->access != 1){
        if ($this->$attribute != $this->getOldAttribute($attribute)){
            $this->addError($attribute, 'Permission denied! You can\'t change your activities!');
        }
    }
    elseif ($this->active == 1){
        if ($this->access == 1 || $this->access == 2) {
            if (!$this->photo){
                $this->addError($attribute, 'To activate user first you must upload avatar!');
            }
        }
        if (!$this->access) {
            $this->addError($attribute, 'To activate user first you must set access!');
        }
    }
}

public function checkConditionsPublished($attribute){//echo 'published'; exit;
    if (Yii::$app->user->identity->access != 1){
        if ($this->$attribute != $this->getOldAttribute($attribute)){
            $this->addError($attribute, 'Permission denied! You can\'t set this field!');
        }
    }
    if ($this->$attribute == 1) {
        if (!$this->photo) {
            $this->addError($attribute, 'To set user as published author first you must upload avatar!');
        }
        if ($this->access == 3) {
            $this->addError($attribute, 'To set user as published author first you must set access as "Admin" or "Writer"');
        }
    }
}
public function checkEmpty($attribute){// echo 'checkEmpty'; exit;
    if (!$this->isNewRecord) {
        if (!$this->$attribute)
        $this->addError($attribute, 'About cen not be blank!');
    }
}

Я заметил, что валидатор напимер checkConditionsAccess не срабатыват только тогда когда полю 'access' пытаются присвоить пустую строку, но когда приходит не пустая строка, то этот валидатор работает нормально. Так же происходит и с валидатором checkEmpty.
Подскажите пожплуйста в чем может быть проблема.