Silverlight 3 RIA services and properties being "flattened" ?

Question

I have a model that looks roughly like this:

private bool IsProduct {get; set;}
private decimal ProductPrice {get; set;}
private decimal TimedRate {get; set;}

    public decimal SingularAmount {
        get {
            if (this.IsProduct) {
                return ProductPrice;
            }
            else {
                return TimedRate;
            }
        }
        set {
            if (this.IsProduct) {
                this.ProductPrice = value;
            }
            else {
                this.TimedRate = value;
            }
        }
    }

I'm binding to this SingularAmount property via RIA Services to Silverlight 3 DataGrid. What I'm finding is that, when I change the property - the respective properties on the model do not get updated. When I step through the code, I can see on the client side, that SingularAmount is set to say 5 for example, the other properties do not get updated.

Seems like when RIA makes the client side version of the classes, this sort of functionality isn't ported over. Any ideas on how to tackle this?

---

Update

Here is the RIA generated code for that property:

    [DataMember()]
    public decimal SingularAmount
    {
        get
        {
            return this._singularAmount;
        }
        set
        {
            if ((this._singularAmount != value))
            {
                this.ValidateProperty("SingularAmount", value);
                this.OnSingularAmountChanging(value);
                this.RaiseDataMemberChanging("SingularAmount");
                this._singularAmount = value;
                this.RaiseDataMemberChanged("SingularAmount");
                this.OnSingularAmountChanged();
            }
        }
    }

Obviously, that doesn't look much like the original server side property.

Answer 1

I'm just learning RIA Services myself, and am wondering if you can override the default constructor in this case? Although, I believe the recommended solution for this scenario is to have a Setter method (as in {obj}.SetPrice(decimal price); instead of doing what you are doing... Just my $0.02

Answer 2

When you're doing any data binding in Silverlight on to standard CLR properties (as opposed to Dependency Properties) then the binding object looks to see if the object implements INotifyPropertyChanged and listens for PropertyChanged events.

Implementing this on your model will cause the binding properties to update in the UI correctly.

There is one caveat though, due to the way your property SingularAmount is implemented (calculated from other values) you'll need to notify the UI about changes to that property as well.

So in the setter of ProductPrice you'll need to raise the PropertyChanged event for ProductPrice as well as Singular Amount.

This http://msdn.microsoft.com/en-us/library/cc278072(VS.95).aspx discusses data binding in Silverlight and how notifications work.