public function actionDropFocus()
{
$courseId = Yii::$app->request->post('courseId');
$userId = Yii::$app->user->id;
if (UserCourse::isFocus($userId, $courseId)) {
if (UserCourse::deleteFocus($userId, $courseId, UserCourse::TYPE_FOCUS)) {
echo true;
return;
}
} else {
echo true;
return;
}
echo false;
}