CRDGenerator: Change format in @PrinterColumn to enum

[baloo42]

Is your task related to a problem? Please describe

To align with the upcoming @AdditionalPrinterColumn annotation and to make this typesafe, the type of format in @PrinterColumn should be changed to an enum.

Describe the solution you'd like

enum PrinterColumnFormat {
    NONE(null),
    INT32("int32"),
    INT64("int64"),
    FLOAT("float"),
    DOUBLE("double"),
    BYTE("byte"),
    DATE("date"),
    DATE_TIME("date-time"),
    PASSWORD("password");

    public final String value;

    Format(String value) {
      this.value = value;
    }

    public String getValue() {
      return value;
    }
  }

This enum should be shared between @AdditionalPrinterColumn and @PrinterColumn.

Describe alternatives you've considered

Phase it out:

1. Add additional enum param formatStrict, deprecate format (with 7.0)
2. Replace format with enum param, deprecate formatStrict (with 8.0)
3. Remove formatStrict (with 9.0)

Additional context

First discussed here:

• fix: adds an additional printer column annotation #6390 (comment)
• fix: adds an additional printer column annotation #6390 (comment)

Note that this would be a breaking change.

[baloo42]

I have already worked on this and discovered a blocker at least for me.

If we change the annotation param format to an enum, we also have to update the old implementation.
The problem is, I don't know how to get the enum value here:

https://github.com/fabric8io/kubernetes-client/blob/main/crd-generator/api/src/main/java/io/fabric8/crd/generator/AbstractCustomResourceHandler.java#L94

If I run the unit tests, I can cast it to the enum. But if I run this via the annotation processor, I'm not able to cast it.
I guess casting is the wrong way. Can someone point me into the right direction?

How can I get the value of an enum from an annotation if sundrio's AptContext is used?

[manusa]

Can someone point me into the right direction?

I don't know about the right direction or the right approach when dealing with APT.

The only thing I can suggest is to do a hacky .from(Object value) in the enum and then deal with the two cases there (i.e. if it's instanceof the enum return it, if not parse it).

[baloo42]

Thanks, you got me somehow into the right direction. com.sun.tools.javac.code.Symbol$VarSymbol implements toString() which is in case of an enum value the name. The following method works:

  // o is in case of running as annotation processor an instance of com.sun.tools.javac.code.Symbol$VarSymbol
  private static Optional<PrinterColumnFormat> findPrinterColumnFormat(Object o) {
    if (o == null) {
      return Optional.empty();
    }

    if (o instanceof PrinterColumnFormat) {
      return Optional.of((PrinterColumnFormat) o);
    }

    String symbol = o.toString();
    return Arrays.stream(PrinterColumnFormat.values())
        .filter(f -> f.name().equals(symbol))
        .findFirst();
  }

Will polish the MR further in the next days.