private static Expression CreateInvoke(DuplexCallback callback, Type returnType, IEnumerable <Expression> arguments = null)
{
return(Expression.Call(
Expression.Constant(callback),
returnType == typeof(void) ? DuplexCallback.serverInvokeVoidMethod : DuplexCallback.serverInvokeMethod.MakeGenericMethod(returnType),
Expression.NewArrayInit(
typeof(object),
(arguments == null ? new Expression[0] : arguments.Select(a => (Expression)Expression.Convert(a, typeof(object)))))));
}
protected override Expression TryEvaluateObservable(object value, Type type, QbservableProtocol protocol)
{
var observableType = value.GetType().GetGenericInterfaceFromDefinition(typeof(IObservable <>));
if (observableType != null)
{
return(DuplexCallback.CreateObservable(protocol, value, observableType.GetGenericArguments()[0], type));
}
return(null);
}
public override Expression Invoke(MethodCallExpression call, ExpressionVisitor visitor, QbservableProtocol protocol)
{
object instance;
if (call.Method.ReturnType == typeof(void))
{
instance = null;
}
else
{
instance = Evaluate(call.Object, visitor, Errors.ExpressionCallMissingLocalInstanceFormat, call.Method);
}
return(DuplexCallback.Create(protocol, instance, call.Method, visitor.Visit(call.Arguments)));
}
protected override Either <object, Expression> TryEvaluateEnumerable(object value, Type type, QbservableProtocol protocol)
{
Expression expression = null;
if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IEnumerable <>))
{
expression = DuplexCallback.CreateEnumerable(protocol, value, type.GetGenericArguments()[0], type);
}
else if (type == typeof(IEnumerable))
{
var enumerable = (IEnumerable)value;
expression = DuplexCallback.CreateEnumerable(protocol, enumerable.Cast <object>(), typeof(object), type);
}
return(expression == null ? null : Either.Right <object, Expression>(expression));
}
public override Expression GetValue(FieldInfo field, MemberExpression member, ExpressionVisitor visitor, QbservableProtocol protocol)
{
object instance = Evaluate(member.Expression, visitor, Errors.ExpressionMemberMissingLocalInstanceFormat, member.Member);
return(DuplexCallback.Create(protocol, instance, field));
}