Convert-DbValue to enum using projections

BIZ TMS Aurelius
1

Is there a way to convert projected enum-values to its enumeration?

I've found TMappingExplorer.DbValueToEnum, that would do this for me, but it's private...

this is the find I'm using:

[Enumeration(TEnumMappingType.emString, 'one,two')]
TEntityEnum = (teOne, teTwo);

TEntity = class
private
  FEnum: TEntityEnum;
public
  property Enum: TEntityEnum read FEnum write FEnum;
end;

// shortened Find:
hResult := ObjectManager.Find<TEntity>.
  Select(TProjections.ProjectionList.Add(EntDic.Entity.Enum)).
  Take(1).UniqueValue;

 hResult.Values[0] = 'one' //or two, but I'd like to use teOne or teTwo...
2

It is private indeed, but you can workaround it using a hack:

type
  TInternalConverter = class(TLegacyDBValueConverter)
  public
    procedure DBToValue(const DBValue: Variant; var Value: TValue); reintroduce;
  end;

{ TInternalConverter }

procedure TInternalConverter.DBToValue(const DBValue: Variant; var Value: TValue);
begin
  inherited DBToValue(DBValue, Value);
end;

{ some code}

procedure TForm2.Button1Click(Sender: TObject);
var
  Conv: TLegacyDBValueConverter;
  Value: TValue;
  Enum: TEntityEnum;
begin
  Conv := Manager.Explorer.FindEntityTypeFromClass(TEntity).AllColumns.Find('Enum').Wrapper as TLegacyDBValueConverter;
  TInternalConverter(Conv).DBToValue('two', Value);
  Enum := Value.AsType<TEntityEnum>;
end;
3

This hack works, but could you just make TMappingExplorer.DbValueToEnum public?
Would be easier ;)

1 Like
4

For now we are rather avoiding publishing too many methods in the explorer. We have a major refactor in sight.

5

Ok, maybe that's why there is no update since february?

6

No, there is no relation.

7

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