protected void UpdateChildBinding()
{
if (_currentChildBinding != null)
{
_currentChildBinding.Changed -= ChildSourceBindingChanged;
_currentChildBinding.Dispose();
_currentChildBinding = null;
}
if (PropertyInfo == null)
{
return;
}
var currentValue = PropertyInfo.GetValue(Source, PropertyIndexParameters());
if (currentValue == null)
{
// value will be missing... so end consumer will need to use fallback values
}
else
{
_currentChildBinding = SourceBindingFactory.CreateBinding(currentValue, _childTokens);
_currentChildBinding.Changed += ChildSourceBindingChanged;
}
}
private void ClearPathSourceBinding()
{
if (_sourceBinding != null)
{
_sourceBinding.Changed -= SourceBindingOnChanged;
_sourceBinding.Dispose();
_sourceBinding = null;
}
}
//TODO: optim: dont recreate the source binding on each datacontext change, as SourcePropertyPath does not change.
//TODO: optim: don't subscribe to the Changed event if the binding mode does not need it.
protected override void OnDataContextChanged()
{
ClearPathSourceBinding();
_sourceBinding = SourceBindingFactory.CreateBinding(DataContext, Description.SourcePropertyPath);
if (_sourceBinding != null)
{
_sourceBinding.Changed += SourceBindingOnChanged;
}
base.OnDataContextChanged();
}
protected override void Dispose(bool isDisposing)
{
if (isDisposing)
{
if (_currentChildBinding != null)
{
_currentChildBinding.Changed -= ChildSourceBindingChanged;
_currentChildBinding.Dispose();
_currentChildBinding = null;
}
}
base.Dispose(isDisposing);
}
public bool TryCreateBinding(object source, PropertyToken currentToken, List <PropertyToken> remainingTokens, out ISourceBinding result)
{
if (source == null)
{
result = null;
return(false);
}
result = remainingTokens.Count == 0 ? CreateLeafBinding(source, currentToken) : CreateChainedBinding(source, currentToken, remainingTokens);
return(result != null);
}
protected bool TryCreateBindingFromExtensions(object source, PropertyToken propertyToken,
List <PropertyToken> remainingTokens, out ISourceBinding result)
{
foreach (var extension in _extensions)
{
if (extension.TryCreateBinding(source, propertyToken, remainingTokens, out result))
{
return(true);
}
}
result = null;
return(false);
}
