Extension adder, return type of add method

[geofjamg]

• Do you want to request a feature or report a bug? bug

• What is the current behavior?

  @Override
  public SubstationPosition read(Substation substation, XmlReaderContext context) throws XMLStreamException {
  Coordinate[] coordinate = new Coordinate[1];
  XmlUtil.readUntilEndElement(getExtensionName(), context.getReader(), () -> {
      double longitude = XmlUtil.readDoubleAttribute(context.getReader(), "longitude");
      double latitude = XmlUtil.readDoubleAttribute(context.getReader(), "latitude");
      coordinate[0] = new Coordinate(latitude, longitude);
  });
  substation.newExtension(SubstationPositionAdder.class)
          .withCoordinate(coordinate[0])
          .add();
  return substation.getExtension(SubstationPosition.class);
  }

• What is the expected behavior? substation.newExtension should return the extension and not the adder to avoid re-getting the extension with substation.getExtension(SubstationPosition.class)

• What is the motivation / use case for changing the behavior? API usability

• Please tell us about your environment:

  • PowSyBl Version: ...
  • OS Version: ...

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, spectrum, etc)

(if a question doesn't apply, you can delete it)

[geofjamg]

I report yesterday discussions:

• it is not the classical design of builder pattern to return the builder instead of the built object
• the original reason for doing this seems to be the chaining of multiple extension creation BUT:
  • there is very few need for that (never seen one example of code for this usage)
  • most of the time we want to get the extension it self (see all XML deserializer)