Yii2 rbac Role assignment is throwing error on signup - php

Question

I am trying to assign a role named 'admin' (already present in auth_item table in database) during signup in yii2. signup() is present inside SignupForm model in common models.
$auth = Yii::$app->authManager;
$authorRole = $auth->getRole('admin');
$auth->assign($authorRole, $user->getId());
but it is throwing an error at vendor\yiisoft\yii2\rbac\DbManager.php as Trying to get property 'name' of non-object .
public function assign($role, $userId)
{
$assignment = new Assignment([
'userId' => $userId,
'roleName' => $role->name,
'createdAt' => time(),
]);
.....
}
this is the function where the error is getting triggered

Answer 1

Implementing a role based access control is a very easy process and you can even load your roles from the database if you want.
Step1: Creating necessary tables in the database [ You can also apply
migrations with console command yii migrate instead of step 1 ]
The first step is to create necessary tables in the database.Below is the sql you need to run in the database.
drop table if exists `auth_assignment`;
drop table if exists `auth_item_child`;
drop table if exists `auth_item`;
drop table if exists `auth_rule`;
create table `auth_rule`
(
`name` varchar(64) not null,
`data` text,
`created_at` integer,
`updated_at` integer,
primary key (`name`)
) engine InnoDB;
create table `auth_item`
(
`name` varchar(64) not null,
`type` integer not null,
`description` text,
`rule_name` varchar(64),
`data` text,
`created_at` integer,
`updated_at` integer,
primary key (`name`),
foreign key (`rule_name`) references `auth_rule` (`name`) on delete set null on update cascade,
key `type` (`type`)
) engine InnoDB;
create table `auth_item_child`
(
`parent` varchar(64) not null,
`child` varchar(64) not null,
primary key (`parent`, `child`),
foreign key (`parent`) references `auth_item` (`name`) on delete cascade on update cascade,
foreign key (`child`) references `auth_item` (`name`) on delete cascade on update cascade
) engine InnoDB;
create table `auth_assignment`
(
`item_name` varchar(64) not null,
`user_id` varchar(64) not null,
`created_at` integer,
primary key (`item_name`, `user_id`),
foreign key (`item_name`) references `auth_item` (`name`) on delete cascade on update cascade
) engine InnoDB;
Step2: Setting up the config file
Now you can set up the config file to use the authmanager as DbManager. This is done by adding the following lines to the components section of your config file
'authManager' => [
'class' => 'yii\rbac\DbManager',
'defaultRoles' => ['guest'],
],
Step3: Adding and assigning roles.
Now you can add roles by simply writing the following code to your corresponding controller.
use yii\rbac\DbManager;
$r=new DbManager;
$r->init();
$test = $r->createRole('test');
$r->add($test);
And you can assign it to the users by
$r->assign($test, 2);
http://www.yiiframework.com/doc-2.0/guide-security-authorization.html
Same answer has been provided here: Yii2 role management with rbac and database storage

Answer 2

I faced the same problem, the reason is because getRole() method returns null as you can see in your app.log file yii\rbac\DbManager->assign(NULL, 1222049)
SOLUTION
Use $auth->getPermission('admin') instead of $auth->getRole('admin')