tatumizer / pigeon_map Goto Github PK

I use this ISSUE simply as a draft copy of posts I'm going to send elsewhere.

Alex, thanks for this extremely useful package, it is working very well right out of the box. I wanted to echo Andrés Viedma's comments from the Dart-Misc mailing list and ask if it would be easy for you to add support for missing fields in Pigeon Structs.

I'm not sure about Andrés but I would be alright with these fields deserializing into uninitialized null values. I took a quick try at hacking it in but I was unable to cope with all the downstream effects of my edits. During serialization, it would be preferable for me to have null struct fields disappear entirely, although your package may be doing this already, I have not tested.

The use case for me is with wrapper messages that can hold a number of different content types. My current workaround is to use a list for each field but If I need to store a large number of these structs as JSON, having all of these fields with no values will get expensive. However, if null fields disappear when serialized and non-existent fields are set as null during deserialization then my storage and transfer costs can be minimized.

The other workaround that comes to mind is using the standard dart library to deserialize the JSON into a map, check for existence, and then convert fields into PigeonStructs if they exist but then I'm paying for two parses.

Please let me know if that makes sense, I can provide an example, or if there's some easier approach you know of that I'm not seeing. Thanks again!

This is a notebook on dart mirrors

    print("location ${declaration.location} isClass=${declaration is ClassMirror}");
    if (declaration is ClassMirror) {
    
      if (declaration.simpleName.name == "X") {
        declaration.invoke(#staticMethod, []);
      }
    } else if (declaration is MethodMirror) { // for top-level functions
       if (declaration.simpleName == Symbol("foo")) {
         library.invoke(Symbol("foo"), []);
      }
    } 

extension SymbolNameExt on Symbol {
  String get name {
    var str = this.toString();
    if (!str.startsWith('Symbol("')) throw 'Weird symbol $str - BUG!';
    return str.substring(str.indexOf('"') + 1, str.lastIndexOf('"'));
  }
}

reading annotations

for (var meta in declaration.metadata) {
      if (meta.type == reflectClass(ExampleAnnotation)) {
        //print("simple name: ${declaration.simpleName.name}");
        //print(meta.getField(#value));
      }
    }
}

computing effective file name with a default directory

extension on Options {
  String get effectiveFileName {
    if (this.destinationFilePath != null) return this.destinationFilePath!;
    String scriptPath = Platform.script.toFilePath();
    String dirname = path.dirname(scriptPath);
    String mainFileName = path.basenameWithoutExtension(scriptPath);
    return '$dirname/$mainFileName.g.dart';
  }
}