(1/1) FatalErrorException Call to a member function all() on null in laravel 5.4 - laravel-5.4

Question

4 and i have a form when submitted i want to validate its fields, what happened is when i submit the form this is what it gets
(1/1) FatalErrorException
Call to a member function all() on null
This is my code below
$validator = app('validator')->make($this->request->all(),[
'postTitle' => 'required',
'postContent' =>'required']);
In laravel 5.2 this validator works well but in laravel 5.4 it returns null
can someone help me figured this thing out?
Any help is muchly appreciated. TIA
this is my full code
<?php
namespace App\Repositories;
use App\Repositories\Contracts\addPostRepositoryInterface;
use Validator;
use Illuminate\Http\Request;
use DB;
use Session;
use Hash;
class addPostRepository implements addPostRepositoryInterface{
protected $request;
// Intialize request instance
public function __contruct(Request $request){
$this->request = $request;
}
public function addPosts(Request $request){
//validate posts
echo "test";
$validator = Validator::make($request->all(), [
'postTitle' => 'required',
'postContent' =>'required',
]);
//if validation fails return error response
if($validator->fails())
return redirect()->route('get.addPost')->withErrors($validator)->withInput();
try{
}catch(\Exception $e){
return redirect()->route('get.addPost')->withErrors(["error"=>"Could not add details! Please try again."])->withInput();
}
}
public function postCreate($screen){
switch($screen){
case 'add':
return $this->addPosts($screen);
break;
}
}
//getAddPost View
public function getAddPost(){
return view('addPost');
}
}

Answer 1

Seems an issue with the method injection (in the constructor) or something.
You may try creating the request object on the local(addPosts()) function.
Please try below alternative solution.
<?php
namespace App\Repositories;
use App\Repositories\Contracts\addPostRepositoryInterface;
use Validator;
use DB;
use Session;
use Hash;
class addPostRepository implements addPostRepositoryInterface{
public function addPosts(Request $request){
//validate posts
$reqeust = new \Illuminate\Http\Request;
$validator = Validator::make($request->all(), [
'postTitle' => 'required',
'postContent' =>'required',
]);
//if validation fails return error response
if($validator->fails())
return redirect()->route('get.addPost')->withErrors($validator)->withInput();
try{
}catch(\Exception $e){
return redirect()->route('get.addPost')->withErrors(["error"=>"Could not add details! Please try again."])->withInput();
}
}
public function postCreate($screen){
switch($screen){
case 'add':
return $this->addPosts($screen);
break;
}
}
//getAddPost View
public function getAddPost(){
return view('addPost');
}
// REST OF THE CODE GOES HERE...
}

Answer 2

Given the information you gave, I will demonstrate you how to validate a request properly in Laravel 5.4
public function store(Request $request)
{
$validator = Validator::make($request->all(), [
'postTitle' => 'required',
'postContent' =>'required',
]);
if ($validator->fails()) {
return redirect('your.view')
->withErrors($validator)
->withInput();
}
// Store the blog post...
}
This will successfully validate the request for you wherever need be. If the validation fails, you will be forwarded to your view with the according errors.
Make sure you use Validator; on top of your file.
For more information, you can read up on https://laravel.com/docs/5.4/validation