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

<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Http\Requests;
use App\Http\Requests\NewWidgetRequest;
use App\Models\Widget;
use App\Models\WidgetType;
use App\Widgets\Exceptions\MissingParameterException;
use Illuminate\Support\Facades\Auth;

class CreateNewWidget extends Controller
{
    /**
     * Form for new widget area
     *
     * @param $type
     *
     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
     */
    public function getNew($type)
    {
        $widgetType = WidgetType::findOrFail($type);

        $presenter = call_user_func([$widgetType->handler, 'getPresenter']);

        return call_user_func([$presenter, 'renderAddForm'], $widgetType);
    }

    /**
     * Create new instance of given widget type
     *
     * @param NewWidgetRequest $request
     * @param                  $type
     *
     * @return \Illuminate\Http\RedirectResponse
     */
    public function postNew(NewWidgetRequest $request, $type)
    {
        $widgetType = WidgetType::findOrFail($type);

        // create new widget
        $widget = new Widget();
        $widget->widget_type_handler = $widgetType->handler;
        $widget->user_id = Auth::user()->id;
        $widget->name = $request->name;

        // save description if available
        if (isset($request->description)) {
            $widget->description = $request->description;
        }

        // try to save this widget
        try {
            $widget = call_user_func([$widgetType->handler, 'save'], $widget, $request);
        } catch (MissingParameterException $e) {
            // user omitted some value
            return $this->invalidWidget($type, $e->getMessage());
        } catch (\Exception $e) {
            // something went wrong
            return $this->invalidWidget($type, trans('admin/widgets.cannotSave', ['exception' => $e->getMessage()]));
        }

        // save into database
        $widget->save();

        // redirect with success notification
        return redirect()
            ->route('widgets.new', ['type' => $type])
            ->with('success', trans('admin/widgets.successfullyCreated'));
    }

    private function invalidWidget($widgetType, $error)
    {
        return redirect()
            ->route('widgets.new', ['type' => $widgetType])
            ->withInput()
            ->with('error', $error);
    }
}