XyzCrudController.php

	public function update(LessonCrudRequest $request)
	{
		$this->crud->hasAccessOrFail('update');
		
		// replace empty values with NULL, so that it will work with MySQL strict mode on
		foreach ($request->input() as $key => $value) {
			if (empty($value) && $value !== '0') {
				$request->request->set($key, null);
			}
		}
		
		// update the row in the db
		$item = $this->crud->update($request->get($this->crud->model->getKeyName()),
			$request->except('redirect_after_save', '_token', '_method', 'tags'));
		
		$item->retag($request->input('tags'));
		
		$this->data['entry'] = $this->crud->entry = $item;
		
		// show a success message
		\Alert::success(trans('backpack::crud.update_success'))->flash();
		
		// save the redirect choice for next time
		$this->setSaveAction();
		
		return $this->performSaveAction();
	}