I have catalog with nested categories and items. Now I have maximum 4 level of depth. Routing for subcategories works well. But when I try go to item page it works only for the items in the max depth category.

• this link works well -> maincat/cat2/cat3/cat4/item
• this link doesn't work -> maincat/cat2/cat3/item
• this link doesn't work -> maincat/cat2/item

It gives me an error showing that route is trying to processed by getCategory function.

at HandleExceptions->handleError('8', 'Trying to get property of non-object', 'D:\OpenServer\domains\myapp.dev\app\Http\Controllers\CatalogController.php', '33', array('cat2' => 'cat2sef', 'cat3' => 'cat3sef', 'cat4' => 'testitem-sef, 'category' => null)) in CatalogController.php line 33

routes.php

Route::get('maincat', 'CatalogController@getIndex');
Route::get('maincat/{cat2}/{cat3?}/{cat4?}', 'CatalogController@getCategory');
Route::get('maincat/{cat2}/{cat3?}/{cat4?}/{item}', 'CatalogController@getItem');

CatalogController.php

class CatalogController extends Controller {

	public function __construct()
	{	

	}

	public function getIndex()
	{
		$category = Category::where('sef', '=', 'maincat')->first();
		$categories = $category->descendants()
							   ->where('parent_id', $category->id)
							   ->orderBy('id', 'asc')
							   ->paginate(12);

		return view('catalog.index')->withCategory($category)
									  ->withCategories($categories);
	}

	public function getCategory($cat2, $cat3 = null, $cat4 = null)
	{
		if (!is_null($cat4)) {
			$category = Category::where('sef', $cat4)->first();
		} elseif (is_null($cat4) && !is_null($cat3)) {
			$category = Category::where('sef', $cat3)->first();
		} else {
			$category = Category::where('sef', $cat2)->first();
		}
		$categories = Category::where('parent_id', $category->id)->get();
		$previous = $category->getPrevSibling();
		$next = $category->getNextSibling();
		$items = Item::where('category_id', $category->id)
							->orWhere('cat2_id', $category->id)->paginate(20);

		return view('catalog.cat')->withCategory($category)
							  		->withCategories($categories)
							  		->withPrevious($previous)
							  		->withNext($next)
							  		->withItems($items);
	}

	public function getItem($cat2, $cat3 = null, $cat4 = null, $item)
	{
		if (!is_null($cat4)) {
			$category = Category::where('sef', $cat4)->first();
		} elseif (is_null($cat4) && !is_null($cat3)) {
			$category = Category::where('sef', $cat3)->first();
		} else {
			$category = Category::where('sef', $cat2)->first();
		}

		$item = Item::where('sef', $item)->first();
		$previous = Item::where('id', '<', $item->id)->orderBy('id', 'desc')->first();
		$next = Item::where('id', '>', $item->id)->orderBy('id', 'asc')->first();

		return view('catalog.item')->withCategory($category)
							   		 ->withItem($item)
							   		 ->withPrevious($previous)
							   		 ->withNext($next);
	}



}