implemented basic value conversion

SimpleMVVM.Binding.Components.pas

@@ -279,7 +279,7 @@ function TEditBinding.Initialize(const observable: IObservable): TFunc<TValue>;
   Result :=
     function: TValue
     begin
-      fComponent.Text := observable.Value.AsString;
+      fComponent.Text := observable.Value.ToString;
     end;
 end;
 

SimpleMVVM.Binding.pas

@@ -82,7 +82,7 @@ procedure ApplyBindings(const view: TComponent; const viewModel: TObject);
           viewModel);
 end;
 
-function CreateObservable(const instance: TObject;
+function CreateObservable(instance: TObject;
   const expression: string): IObservable;
 
   function CreateRootProp(const prop: TRttiProperty; const instance: TObject): IObservable;
@@ -134,6 +134,7 @@ function CreateObservable(const instance: TObject;
   begin
     prop := typ.GetProperty(expressions[i]);
     if Assigned(prop) then
+    begin
       if StartsText('IObservable<', prop.PropertyType.Name) then
       begin
         Result := prop.GetValue(instance).AsInterface as IObservable;
@@ -147,6 +148,9 @@ function CreateObservable(const instance: TObject;
           Result := CreateSubProp(prop, Result);
         typ := prop.PropertyType;
       end;
+      if i < High(expressions) then
+        instance := prop.GetValue(instance).AsObject;
+    end;
   end;
 end;
 

SimpleMVVM.Observable.pas

@@ -102,8 +102,29 @@   TDependentObservable<T> = class(TObservableBase, IObservable<T>)
     constructor Create(const getter: TFunc<T>; const setter: TAction<T>); overload;
   end;
 
+type
+  TValueHelper = record helper for TValue
+    function ToType<T>: T;
+  end;
+
 implementation
 
+uses
+  TypInfo;
+//  Spring;
+
+function TValueHelper.ToType<T>: T;
+begin
+  // hardcode some simple conversions for demo purpose - use Spring4D value converter later
+  case Kind of
+    tkUString:
+      case PTypeInfo(System.TypeInfo(T)).Kind of
+        tkInteger: PInteger(@Result)^ := StrToInt(AsString);
+      end;
+  end;
+end;
+
+
 
 {$REGION 'TObservableBase'}
 
@@ -200,7 +221,9 @@ function TDependentObservable.GetValueNonGeneric: TValue;
 
 procedure TDependentObservable.SetValueNonGeneric(const value: TValue);
 begin
-  fSetter(value);
+  if fIsNotifying then Exit;
+  if Assigned(fSetter) then
+    fSetter(value);
   inherited Changed;
 end;
 
@@ -247,8 +270,9 @@ procedure TObservable<T>.SetValue(const value: T);
 
 procedure TObservable<T>.SetValueNonGeneric(const value: TValue);
 begin
-  SetValue(value.AsType<T>);
+  SetValue(value.ToType<T>);
 end;
+
 {$ENDREGION}
 
 
@@ -305,13 +329,15 @@ function TDependentObservable<T>.GetValueNonGeneric: TValue;
 
 procedure TDependentObservable<T>.SetValue(const value: T);
 begin
-  fSetter(value);
+  if fIsNotifying then Exit;
+  if Assigned(fSetter) then
+    fSetter(value);
   inherited Changed;
 end;
 
 procedure TDependentObservable<T>.SetValueNonGeneric(const value: TValue);
 begin
-  SetValue(value.AsType<T>);
+  SetValue(value.ToType<T>);
 end;
 
 {$ENDREGION}