XDataQuery in Service Operation: Incompatible type string and TXDataQuery

[Winkel_Philipp1 (Winkel Philipp)]

Hi,
I'm trying to invoke a service operation with a query. The Documentation (Service Operations | TMS XData documentation) says I can do this with the TXDataClient and the QueryBuilder

  IMyService = interface(IInvokable)
    [HttpGet] function List(Query: TXDataQuery): TList<TCustomer>;

  Customer := Client.Service<IMyService>.List(
    CreateQuery.From(TCustomer)
      .Filter(Linq['Name'] eq 'Foo')
      .OrderBy('Name')
      .Top(10).Skip(30)
      .QueryString
  );

But the Client doesn't compile this.... Incompatible type string and TXDataQuery.
What I'm missing?

Thank you!

[wlandgraf (Wagner Landgraf)]

That's because you are calling directly using the interface, which of course requires you to pass a TXDataQuery object.

Thus that's what you can do, simply pass the XDataQuery object:

  QueryReq := TXDataQuery.Create('Name eq ''foo''', 'Name', 10, 30);
  XClient.ReturnedEntities.Add(QueryReq);
  Query := XClient.Service<IMyService>.List(QueryReq);

I agree, though, that the XData Query Builder could also return a TXDataQuery object In addition to a string, for those cases.

[Winkel_Philipp1 (Winkel Philipp)]

Thank you for your reply.

Hmm.. maybe the documentation is wrong? The code above is from the the current documentation.

[wlandgraf (Wagner Landgraf)]

Indeed, it's wrong. We will fix it.

[wlandgraf (Wagner Landgraf)]

We have now added the Build method to TXDataQueryBuilder to allow creating a TXDataQuery object from it.

The documentation has been updated accordingly, here is how to use it:

  Query := CreateQuery
    .From(TCustomer)
    .Filter(Linq['Name'] = 'Foo')
    .OrderBy('Name')
    .Top(10).Skip(30)
    .Build;
  XClient.ReturnedEntities.Add(Query);
  Customer := Client.Service<IMyService>.List(Query);

Such improvements will be available in version 5.20.