Cannot set property for Model class in Laravel

Question

I'm trying add dependency injection on User class and after few hours trying, I found this way:

I added this code to App\Models\User class

    public function __construct()
    {
        $this->roleService = resolve(RoleService::class);
    }

I've checked $this->roleService value, it work normally, buut when I try to use it in a function:

    public function isAdmin() {
        return $this->roleService->isAdmin($this->role_id);
    }

This function throw an error Call to a member function isAdmin() on null. When I logged $this->roleService, it returned null.

Anyone can solve this?

Have you declared `protected $roleService;` variable before your constructor ? Also don't you think your constructor should be like this `public function __construct(User $user)` and then `$this->roleService = $user;` ? — Vipertecpro, Feb 13 '20 at 06:02
+ I tried to declare ```$roleService``` and it doesn't work. I think it isn't matter because I've tried to remove it on other class and it worked normally. + If I modify constructor to ```public function __construct(User $user)```, it probably throw error because constructor of Model parent class initialized with 1 parameter like this ```__construct(array $attributes = array())``` — simpsons3, Feb 13 '20 at 07:41
Can you please dd this `dd( $this->roleService)` in isAdmin() and in __construct() — Vipertecpro, Feb 13 '20 at 08:10
using in ```__construct()``` returned instance of ```RoleService``` class but using in ```isAdmin()``` return ```null``` — simpsons3, Feb 13 '20 at 08:53
That's great that you've resolved it, could you update your answer with code which you've refactored ? — Vipertecpro, Feb 13 '20 at 09:47

Ahmed Shefeer · Answer 1 · 2020-02-13T07:48:08.053

0

Create a custom accessor for your model, and get/set the value from there.

public function getRoleServiceAttribute ()
{
    if(is_null($this->roleService)){
        $this->roleService = resolve(RoleService::class);
    }

    return $this->roleService;
}

Then you can access the attribute as $this->role_service

Also make sure you declare the $roleService class property as protected, to avoid accidental access as $this->roleService from anywhere else.

edited Feb 13 '20 at 07:48

answered Feb 12 '20 at 09:45

Ahmed Shefeer

386
2
12

it doesn't work. Error ```Call to a member function find() on null``` returned. – simpsons3 Feb 12 '20 at 11:25
can you access it via User::find(1)->roleService? – Ahmed Shefeer Feb 12 '20 at 13:58
No, it return ```null``` value. – simpsons3 Feb 13 '20 at 01:18
I have updated my answer, check if it works for you. – Ahmed Shefeer Feb 13 '20 at 07:46
it doesn't work. It throw an error ```Undefined property: App\Models\User::$roleService``` – simpsons3 Feb 13 '20 at 08:54
When you are accessing it, you should access it like `$this->role_service` – Ahmed Shefeer Feb 13 '20 at 11:41

score 0 · Answer 2 · answered Feb 13 '20 at 09:01

Thank for help. I just have referenced answer of an expert. He said that we should not dependency injection in Model class because it will broke project structure. Project should be followed structure: Controller->Service->Repository->Model->Database. So, I'll refactor my code follow it.

Cannot set property for Model class in Laravel

2 Answers2