public void Update(ShopItem valueItem)
{
ShopItem repositoryItem = Get(valueItem.ArticleNumber);
if (repositoryItem == null)
{
throw new Exception(String.Format("Trying to update an item that does not exist yet: ({0})", valueItem.ToString()));
}
if (!repositoryItem.Equals(valueItem))
{
repositoryItem.Assign(valueItem);
}
if (!SaveOnClose)
{
context.Put(repositoryItem);
}
}