/// <summary>
/// Initializes a new instance.
/// </summary>
/// <param name="query"></param>
internal ObservableView(ObservableQuery <TElement> query)
{
expression = query.Expression;
// establish root operation, hook up events, and load
operation = (Operation <IEnumerable <TElement> >)OperationFactory.FromExpression <IEnumerable <TElement> >(new OperationContext(), expression);
SubscribeOperation(operation);
OperationChanged(null, operation.Value);
}
/// <summary>
/// Enables or disables null protection for the given <see cref="ObservableQuery"/>.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="self"></param>
/// <returns></returns>
public static ObservableQuery <T> WithNullSafe <T>(this ObservableQuery <T> self, bool enable)
{
Contract.Requires <ArgumentNullException>(self != null);
return((ObservableQuery <T>)self.Provider.CreateQuery <T>(
Expression.Call(
WithNullSafeMethodInfo.MakeGenericMethod(typeof(T)),
Expression.Convert(self.Expression, typeof(ObservableQuery <T>)),
Expression.Constant(enable, typeof(bool)))));
}
/// <summary>
/// Enables or disables null protection for the given <see cref="ObservableQuery"/>.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="self"></param>
/// <returns></returns>
public static ObservableQuery <T> WithNullSafe <T>(this ObservableQuery <T> self, bool enable)
{
if (self == null)
{
throw new ArgumentNullException();
}
return((ObservableQuery <T>)self.Provider.CreateQuery <T>(
Expression.Call(
WithNullSafeMethodInfo.MakeGenericMethod(typeof(T)),
Expression.Convert(self.Expression, typeof(ObservableQuery <T>)),
Expression.Constant(enable, typeof(bool)))));
}
