core/app/Http/Controllers/Admin/Settings.php

<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Http\Requests;
use Illuminate\Support\Facades\App;

class Settings extends Controller
{
    /**
     * @var \App\Models\Settings
     */
    protected $settings;

    /**
     * Settings constructor.
     *
     * @param \App\Models\Settings $settings
     */
    public function __construct(\App\Models\Settings $settings)
    {
        $this->settings = $settings;
    }

    public function getOverview()
    {
        $sections = App::make('registerSettingsExtension')
                       ->get();
        $settings = $this->settings->getAll();

        return view('admin.settings.overview', [
            'formSections' => $sections,
            'settings'     => $settings
        ]);
    }

    public function saveSettings(Requests\SaveSettingsRequest $request)
    {
        $data = $request->all();
        // remove CSRF token field
        unset($data['_token']);

        $settings = $this->settings->getAll();
        $updated = 0;
        foreach ($data as $key => $value) {
            if (isset($settings->$key)) {
                if ($settings->$key != $value) {
                    $updated++;
                    \App\Models\Settings::where('key', $key)
                                        ->update(['value' => $value]);
                }
            } else {
                \App\Models\Settings::create(['key' => $key, 'value' => $value]);
                $updated++;
            }
        }

        if ($updated > 0) {
            return redirect()
                ->route('settings.overview')
                ->with('success', trans('admin/settings.successfullySaved'));
        } else {
            return redirect()
                ->route('settings.overview')
                ->with('error', trans('admin/settings.nothingToSave'));
        }
    }
}