[fpc-devel] [] property overloads

[Marcus Marques da Rocha]

It is possible to do that using variant type. I have done it as below:

property DocumentElementChildNodes[Index1: Variant] : TPXMLNode read 
getChildNode; default;

function TPXMLNode.getChildNode(Index1 : Variant): TPXMLNode;
begin
   Result := nil;
   if assigned(Self) and assigned(FChildNodes) then
     if (varType(Index1) = varString) or (varType(Index1) = varUString) then
     begin
       if (IndexOf(Index1) = -1) then
         if FAutoCreateChildren then
           result := TPXmlNode(self.addchild(Index1))
         else
           result := nil
       else
         Result := TPXMLNode( FChildNodes.objects[IndexOf(Index1)]);
     end
     else
       Result := TPXMLNode(FChildNodes.objects[Index1]);
end;

Regards

Marcus Rocha.




Em 20/06/2019 14:57, Ryan Joseph escreveu:
> I just had some plans for a cool JSON class thwarted because apparently [] properties don’t allow overloading of the parameters. Can we allow multiple default properties as long as their parameters are different? I know there’s not overloading of property names but at least the parameters could be overloadable so the correct property is chosen depending on what the args are.
>
> type
>    TMyClass = class
>      function GetValueWithInt(index: integer): TValue;
>      function GetValueWithString(index: string): TValue;
>      property IndexI[index: integer]: TValue read GetValueWithInt; default;
>      property IndexS[index: string]: TValue read GetValueWithString; default;
>    end;
>
>   
> o := c[index]; // IndexI wins
> o := c[‘key’]; // IndexS wins
>
> Regards,
> 	Ryan Joseph
>
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