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LinkedData

function LinkedData: TdaQueryDataView;

Example​

procedure ScriptEvent(var Value: variant);
var
  View: TdaQueryDataView;
begin
  View := LinkedData;
  Value := Assigned(View);
end;

Usage​

LinkedData returns the current linked query data view for the active field or view map context.

Parameters

None.

Returns

  • For a TvxFieldMap context: MapItem.ViewMap.GetCurrentLinkedView.
  • For a TvxViewMap context: MapItem.GetCurrentLinkedView.
  • For no map item or another map-item type: nil.

The returned view is a live context-owned object. Ownership never transfers to the script.

Additional Technical Info​

LinkedData returns the current linked query data view associated with the scripter's active field-map or view-map context. It can legitimately return nil outside those contexts.

The example checks availability before use. It is source-reviewed and was not executed.

Implementation and availability quirk

The method initializes Result := nil, tests MapItem, then performs the two runtime type branches above. It does not create, copy or rebind a view.

Velox deliberately does not register this no-argument function in the special LinkedData-event scripter. That event already has a parameter named LinkedData; omitting the helper avoids a compiler-name collision. Within that event, use the supplied parameter instead.

State, lifetime and side effects

Calling the helper itself does not move a cursor, but the returned object represents mutable current linked state. Other mapping work can advance, re-evaluate or replace that state. Do not free it, retain it after the event, or assume it is a snapshot.

Errors and concurrency

Unsupported context returns nil rather than raising. Errors inside the context's GetCurrentLinkedView are not caught here. The object follows active map execution and is not safe for cross-thread or cross-execution retention.

Remarks

This function is semantically different from GetLinkedData, which accepts a dataset and aliases LinkDataView. Always test the returned object with Assigned unless the event contract guarantees linked data.

Related entries

Created 2026-07-15