private static LambdaExpression GetExpression(IQueryable source, Func <dynamic, dynamic> expressionBuilder)
{
ParameterExpression parameterExpression = Expression.Parameter(GetElementType(source), expressionBuilder.Method.GetParameters()[0].Name);
DynamicExpressionBuilder dynamicExpression = expressionBuilder(new DynamicExpressionBuilder(parameterExpression));
Expression body = dynamicExpression.Expression;
return(Expression.Lambda(body, parameterExpression));
}
public override bool TryUnaryOperation(UnaryOperationBinder binder, out object result)
{
if (binder.Operation == ExpressionType.IsFalse || binder.Operation == ExpressionType.IsTrue)
{
result = false;
return(true);
}
result = new DynamicExpressionBuilder(Expression.MakeUnary(binder.Operation, Expression, binder.ReturnType));
return(true);
}
public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
{
// TODO: As a first attempt we can use the member names of the parameters to try and resolve the overload
MethodInfo methodInfo = null;
if (args.Any(a => a == null))
{
methodInfo = Expression.Type.GetMethod(binder.Name);
}
else
{
var types = args.Select(arg => arg.GetType()).ToArray();
methodInfo = Expression.Type.GetMethod(binder.Name, types);
}
if (methodInfo != null)
{
var expression = Expression.Call(Expression, methodInfo, args.Select(Expression.Constant));
result = new DynamicExpressionBuilder(expression);
return(true);
}
return(base.TryInvokeMember(binder, args, out result));
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
result = new DynamicExpressionBuilder(Expression.Property(Expression, binder.Name));
return(true);
}