public void When_DependencyProperty_FallbackValue_binding()
{
MyControl.MyPropertyProperty.ToString();
var SUT = new MyControl();
SUT.SetBinding(MyControl.MyPropertyProperty, new Binding("TargetValue")
{
FallbackValue = 42
});
Assert.AreEqual(42, SUT.MyProperty);
var source = new Target2();
source.TargetValue = 10;
SUT.DataContext = source;
Assert.AreEqual(10, SUT.MyProperty);
SUT.DataContext = null;
Assert.AreEqual(42, SUT.MyProperty);
SUT.DataContext = source;
Assert.AreEqual(10, SUT.MyProperty);
}
public void When_DependencyProperty_FallbackValue_VisibilityStringConversion_binding()
{
MyControl.MyPropertyProperty.ToString();
var SUT = new MyControl();
var source = new Target2();
Assert.AreEqual(Visibility.Visible, SUT.MyVisibilityProperty);
SUT.SetBinding(MyControl.MyVisibilityPropertyProperty, new Binding("Object")
{
FallbackValue = "Collapsed"
});
Assert.AreEqual(Visibility.Collapsed, SUT.MyVisibilityProperty);
SUT.DataContext = source;
Assert.AreEqual(Visibility.Visible, SUT.MyVisibilityProperty);
source.Object = 10;
Assert.AreEqual(Visibility.Collapsed, SUT.MyVisibilityProperty);
source.Object = Visibility.Visible;
Assert.AreEqual(Visibility.Visible, SUT.MyVisibilityProperty);
SUT.DataContext = null;
Assert.AreEqual(Visibility.Collapsed, SUT.MyVisibilityProperty);
}
public void When_DependencyProperty_TargetNullValue_binding()
{
var tomato = SolidColorBrushHelper.Tomato;
MyControl.MyPropertyProperty.ToString();
var SUT = new MyControl();
SUT.SetBinding(MyControl.MyBrushPropertyProperty, new Binding("Brush")
{
TargetNullValue = tomato
});
var source = new Target2();
SUT.DataContext = source;
source.Brush = null;
Assert.AreEqual(tomato, SUT.MyBrushProperty);
source.Brush = SolidColorBrushHelper.Olive;
Assert.AreEqual(SolidColorBrushHelper.Olive.Color, (SUT.MyBrushProperty as SolidColorBrush)?.Color);
source.Brush = null;
Assert.AreEqual(tomato, SUT.MyBrushProperty);
}
public void When_Inherited_data_Context_and_Changed()
{
var SUT = new Target1();
var child = new Target2(SUT);
child.SetBinding(Target2.DataContextProperty, new Binding("Child"));
child.SetBinding("TargetValue", new Binding("Value"));
SUT.ChildrenBinders.Add(child);
var source = new MySource();
SUT.DataContext = source;
Assert.AreEqual(42, child.TargetValue);
Assert.AreEqual(1, child.TargetValueSetCount);
Assert.AreEqual(1, SUT.DataContextChangedCount);
Assert.AreEqual(1, child.DataContextChangedCount);
source.Child = new MySource2(44);
Assert.AreEqual(44, child.TargetValue);
Assert.AreEqual(2, child.TargetValueSetCount);
Assert.AreEqual(1, SUT.DataContextChangedCount);
Assert.AreEqual(2, child.DataContextChangedCount);
}
public void When_Inherited_data_Context_And_Converter_Different_Types_Invalid_Child_Path()
{
var SUT = new Target1();
var child = new Target2(SUT);
var converter = new BoolToNumber();
child.SetBinding("DataContext", new Binding("Item.List[0]"));
child.SetBinding("TargetValue", new Binding("Details_zzz.InfoBoolean", converter: converter)
{
FallbackValue = 10
});
SUT.ChildrenBinders.Add(child);
// With the invalid path (Details_zzz instead of Details), the converter should not be called at all.
// FallbackValue should be used
SUT.DataContext = new SourceLevel0()
{
Item = new SourceLevel1()
{
List = new SourceLevel2[] { new SourceLevel2() }
}
};
Assert.AreEqual(10, child.TargetValue);
Assert.AreEqual(0, converter.ConversionCount);
Assert.AreEqual(null, converter.LastValue);
}
public void When_DependencyProperty_OneWay_binding()
{
var SUT = new MyControl();
SUT.SetBinding(MyControl.MyPropertyProperty, new Binding("TargetValue"));
var source = new Target2();
source.TargetValue = 42;
SUT.DataContext = source;
Assert.AreEqual(42, SUT.MyProperty);
SUT.MyProperty = 43;
Assert.AreEqual(42, source.TargetValue);
}
public void When_DataContext_Changed_With_TwoWay_Binding()
{
// Tests both Value and Reference types
var targetA = new Target2()
{
TargetValue = 10, Brush = SolidColorBrushHelper.Tomato
};
var targetB = new Target2()
{
TargetValue = 20, Brush = SolidColorBrushHelper.Olive
};
var control = new MyControl();
control.SetBinding("MyProperty", new Binding {
Path = "TargetValue", Mode = BindingMode.TwoWay
});
control.SetBinding("MyBrushProperty", new Binding {
Path = "Brush", Mode = BindingMode.TwoWay
});
control.DataContext = targetA;
Assert.AreEqual(10, targetA.TargetValue);
Assert.AreEqual(SolidColorBrushHelper.Tomato.Color, (targetA.Brush as SolidColorBrush).Color);
// This test used to fail because changing the DataContext would dispose the previous PropertyChanged subscription,
// which would clear the value and RaisePropertyChanged with null,
// which would propagate that value up to the new DataContext (with TwoWay binding enabled).
control.DataContext = targetB;
Assert.AreEqual(20, targetB.TargetValue);
Assert.AreEqual(SolidColorBrushHelper.Olive.Color, (targetB.Brush as SolidColorBrush).Color);
// Making sure tat setting DataContext to null doesn't affect previous DataContexts
control.DataContext = null;
Assert.AreEqual(10, targetA.TargetValue);
Assert.AreEqual(20, targetB.TargetValue);
Assert.AreEqual(SolidColorBrushHelper.Tomato.Color, (targetA.Brush as SolidColorBrush).Color);
Assert.AreEqual(SolidColorBrushHelper.Olive.Color, (targetB.Brush as SolidColorBrush).Color);
// Making sure that TargetValue is only set once (object initializer)
// There used to be issues where changing the DataContext would cause TwoWay binding to propagate invalid changes to the source.
Assert.AreEqual(1, targetA.TargetValueSetCount);
Assert.AreEqual(1, targetA.TargetValueSetCount);
Assert.AreEqual(1, targetA.BrushSetCount);
Assert.AreEqual(1, targetA.BrushSetCount);
}
public void When_Object_AttachedProperty_binding()
{
var SUT = new Target1();
SUT.SetBinding(Attachable.MyValueProperty, new Binding("TargetValue"));
var source = new Target2();
source.TargetValue = 42;
SUT.DataContext = source;
Assert.AreEqual(42, Attachable.GetMyValue(SUT));
Attachable.SetMyValue(SUT, 43);
Assert.AreEqual(42, source.TargetValue);
}
public void When_Direct_data_Context_binding()
{
var SUT = new Target1();
var child = new Target2();
// Bypass the inheritance
child.SetBinding(Target1.DataContextProperty, new Binding("Child"));
child.SetBinding(Target2.TargetValueProperty, new Binding("Value"));
SUT.ChildrenBinders.Add(child);
var source = new MySource();
SUT.DataContext = source;
Assert.AreEqual(42, child.TargetValue);
Assert.AreEqual(1, child.TargetValueSetCount);
}
public void When_Inherited_data_Context_And_Converter()
{
var SUT = new Target1();
var child = new Target2(SUT);
child.SetBinding(Target2.DataContextProperty, new Binding("Child"));
child.SetBinding("TargetValue", new Binding("Value", converter: new OppositeConverter()));
SUT.ChildrenBinders.Add(child);
var source = new MySource();
SUT.DataContext = source;
Assert.AreEqual(-42, child.TargetValue);
Assert.AreEqual(1, child.TargetValueSetCount);
source.Child = new MySource2(43);
Assert.AreEqual(-43, child.TargetValue);
Assert.AreEqual(2, child.TargetValueSetCount);
}
public void When_DependencyProperty_TWoWay_binding()
{
MyControl.MyPropertyProperty.ToString();
var SUT = new MyControl();
SUT.SetBinding(MyControl.MyPropertyProperty, new Binding("TargetValue")
{
Mode = BindingMode.TwoWay
});
var source = new Target2();
source.TargetValue = 42;
SUT.DataContext = source;
Assert.AreEqual(42, SUT.MyProperty);
SUT.MyProperty = 43;
Assert.AreEqual(43, source.TargetValue);
}
public void When_Inherited_data_Context_Sequence_And_Converter()
{
var SUT = new Target1();
var child = new Target2(SUT);
var converter = new OppositeConverter();
child.SetBinding(Target2.DataContextProperty, new Binding("Item.List[0]"));
child.SetBinding("TargetValue", new Binding("Details.Info", converter: converter)
{
FallbackValue = 10
});
SUT.ChildrenBinders.Add(child);
SUT.DataContext = new SourceLevel0();
Assert.AreEqual(10, child.TargetValue);
Assert.AreEqual(0, converter.ConversionCount);
Assert.AreEqual(null, converter.LastValue);
SUT.DataContext = null;
Assert.AreEqual(10, child.TargetValue);
Assert.AreEqual(0, converter.ConversionCount);
Assert.AreEqual(null, converter.LastValue);
SUT.DataContext = new SourceLevel0();
Assert.AreEqual(10, child.TargetValue);
Assert.AreEqual(0, converter.ConversionCount);
Assert.AreEqual(null, converter.LastValue);
SUT.DataContext = null;
Assert.AreEqual(10, child.TargetValue);
Assert.AreEqual(0, converter.ConversionCount);
Assert.AreEqual(null, converter.LastValue);
SUT.DataContext = new SourceLevel0()
{
Item = new SourceLevel1()
{
List = new SourceLevel2[] { new SourceLevel2() }
}
};
Assert.AreEqual(-1000, child.TargetValue);
Assert.AreEqual(1, converter.ConversionCount);
Assert.AreEqual(1000, converter.LastValue);
// It breaks here, when a broken binding would replace a fully functional one.
SUT.DataContext = new SourceLevel0();
Assert.AreEqual(10, child.TargetValue);
Assert.AreEqual(2, converter.ConversionCount);
Assert.AreEqual(null, converter.LastValue);
SUT.DataContext = new SourceLevel0()
{
Item = new SourceLevel1()
{
List = new SourceLevel2[] { new SourceLevel2() }
}
};
Assert.AreEqual(-1000, child.TargetValue);
Assert.AreEqual(3, converter.ConversionCount);
Assert.AreEqual(1000, converter.LastValue);
SUT.DataContext = null;
Assert.AreEqual(10, child.TargetValue);
Assert.AreEqual(4, converter.ConversionCount);
Assert.AreEqual(null, converter.LastValue);
SUT.DataContext = new SourceLevel0()
{
Item = new SourceLevel1()
{
List = new SourceLevel2[] { new SourceLevel2() }
}
};
Assert.AreEqual(-1000, child.TargetValue);
Assert.AreEqual(5, converter.ConversionCount);
Assert.AreEqual(1000, converter.LastValue);
}
