Encore\Admin\Form::update PHP Method

    public function update($id)
    {
        $data = Input::all();
        if (!$this->validate($data)) {
            return back()->withInput()->withErrors($this->validator->messages());
        }
        $this->model = $this->model->with($this->getRelations())->findOrFail($id);
        $this->setFieldOriginalValue();
        $this->prepare($data, $this->saving);
        DB::transaction(function () {
            $updates = $this->prepareUpdate($this->updates);
            foreach ($updates as $column => $value) {
                $this->model->setAttribute($column, $value);
            }
            $this->model->save();
            $this->updateRelation($this->relations);
        });
        $this->complete($this->saved);
        return redirect($this->resource());
    }