What is the best practice for readonly lists in NHibernate

Question

Domain Model I am working on has root aggregate and child entities. Something like the following code:

class Order
{
   IList Lines {get;se         


        

Answer 1

I have spent several days looking for a best approach for readonly lists in NHibernate. This discussion helped me a lot to form the one that fits our project.

There is an approach I started to use:

1. Backing fields are used to store collections
2. IEnumerable< T> is used to expose collections to force clients use AddLine() and RemoveLine() methods.
3. ReadOnlyCollection type is used in addition to IEnumerable.

Code:

public class Order
{
    private readonly IList lines = new List();

    public virtual IEnumerable Lines
    {
        get
        {
            return new ReadOnlyCollection(lines);
        }
    }

    public void AddLine(OrderLine line)
    {
        if (!lines.Contains(line))
        {
            this.lines.Add(line);
            line.Order = this;
        }
    }

    public void RemoveLine(OrderLine line)
    {
        if (lines.Contains(line))
        {
            this.lines.Remove(line);
            line.Order = null;
        }
    }
}

public class OrderLine
{
    public Order Order { get; set; }
}