Variable in all controller and view fullcalendar laravel 5.6 - development

Variable in all controller and view fullcalendar laravel 5.6

I use fullcalendar in my web site in laravel 5.6 and it working but when i change view i have this problem :

Undefined variable: calendar_details

In my view layout.app i have this :

{!! $calendar_details->script() !!}

Can i define this var in all controller and view to avoid all problem ?

This is my EventsController.php

namespace AppHttpControllers;

use IlluminateHttpRequest;
use IlluminateSupportFacadesRedirect;
use AppHttpControllersController;
use Auth;
use Validator;
use AppEvents;

use Calendar;

class EventsController extends Controller
{
    public function index(){
        $events = Events::get();
        $event_list = [];
        foreach ($events as $key => $event){
            $event_list[] = Calendar::event(
                $event->event_name,
                true,
                new DateTime($event->start_date),
                new DateTime($event->end_date)
            );
        }
        $calendar_details = Calendar::addEvents($event_list);

        return view('events', compact('calendar_details'));
    }

    public function addEvent(Request $request){
        $validator = Validator::make($request->all(), [
            'event_name' => 'required',
            'start_date' => 'required',
            'end_date' => 'required',
        ]);

        if ($validator->fails()){
            Session::flash('warning', 'Veuillez entrer des informations valide');
            return Redirect::to('/events')->withInput()->withErrors('warning');
        }

        $event = new Events;
        $event->event_name = $request['event_name'];
        $event->start_date = $request['start_date'];
        $event->end_date = $request['end_date'];
        $event->save();

        Session::flash('success', 'Evènement ajouté avec succès');
        return Redirect::to('/events');

    }

}

and this is my Events.php :

<?php

namespace App;

use IlluminateDatabaseEloquentModel;

class Events extends Model
{
    protected $fillable = [
        'event_name', 'start_date', 'end_date'
    ];
}

from Laravel Questions and Answers https://laravelquestions.com/laravel/variable-in-all-controller-and-view-fullcalendar-laravel-5-6/
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