Call to a member function getPaginate() on a non-object - php

Question

I'm new to laravel framwork , and I'm coding my first web app
and getting the following error
FatalErrorException in PersonController.php line 26:
Call to a member function getPaginate() on a non-object
this is my Controller
<?php
namespace App\Http\Controllers;
use App\Repositories\PersonRepository;
class PersonController extends Controller
{
protected $personRepo ;
protected $nbrPerPage = 4 ;
public function _construct(PersonRepository $personRepository)
{
$this->personRepo = $personRepository ;
}
public function index()
{
$persons = $this->personRepo->getPaginate(nbrPerPage);
$links = $persons->setPath('')->render();
return view('index', compact('persons', 'links'));
}
public function create()
{
}
public function store()
{
}
public function show($id)
{
//
}
public function edit($id)
{
//
}
public function update($id)
{
//
}
public function destroy($id)
{
//
}
}
and this my repository class
<?php
namespace App\Repositories ;
use App\Person ;
use App\User;
class PersonRepository {
protected $person ;
public function _construct (Person $person)
{
$this->$person = $person ;
}
public function getPaginate($n)
{
return $this->person-> paginate($n) ;
}
}

Answer 1

You are instantiating an empty instance of the Person model and then trying to call paginate() on it in your repository. However, paginate() is meant to be called on either a query builder object or an Eloquent query. Assuming that you want to return paginated results of all your models, you can scrap the $person property entirely as well as the constructor and then just change your method to this:
public function getPaginate($n)
{
return Person::paginate($n) ;
}
I will say that for such a simple query, I would suggest not using a repository altogether and just use Person::paginate($n) inside your controller, as Eloquent essentially functions as a repository already.

Answer 2

Unless these are just typos in the question, you have a lot of typos in your code.
The typo that is causing this specific error is that the name of the constructor method should be __construct (with two underscores), not _construct (with one underscore).
Since the constructor method is misspelled on your PersonController, this method is never called and the personRepo attribute is never set. Since it is never set, the line $persons = $this->personRepo->getPaginate(nbrPerPage); is trying to call getPaginate() on a non-object.
Additional typos/issues I see at a glance:
$persons = $this->personRepo->getPaginate(nbrPerPage);
nbrPerPage is being used as a constant. This is incorrect. Should be:
$persons = $this->personRepo->getPaginate($this->nbrPerPage);
Constructor on PersonRepository also misspelled. Should be __construct(), not _construct.
$this->$person = $person ;
This is inside the attempted construct of the PersonRepository. The $ needs to be removed from $this->$person. Should be:
$this->person = $person;