DDD update sample

gistfile1.cs

public class TradeController
{
	private readonly IRepository<Trade> _Trades;

	public TradeController(IRepository<Trade> trades)
	{
		_Trades = trades;
	}

	[ValidationExceptionFilter]
	public JsonResult Update(UpdateTrade parameters)
	{
		var trade = _Trades.Get(parameters.Id);
		trade.Update(parameters);
		return Json(new {success = true});
	}
}


public class Trade
{
	public Guid Id { get; private set; }
	public decimal Quantity { get; private set; }
	public decimal Price { get; private set; }

	public void Update(UpdateTrade parameters)
	{
		// Of course I'd expect a little more complex validation logic
		if(parameters.Price <= 0)
		{
			throw new ValidationException("Price must be greater than zero.");
		}
		Price = parameters.Price;
		Quantity = parameters.Quantity;
	}
}

// input model -- usually not exactly equivalent to the domain model
public class UpdateTrade
{
	public Guid Id { get; set; }
	public decimal Quantity { get; set; }
	public decimal Price { get; set; }
}