Integration with mobx

[k-paxian]

Integration with mobx

[1N50MN14]

Hi @k-paxian thanks for supporting mobx!

Bumping mobx from ^0.3.9 to latest ^0.4.0+1 I'm now getting the following error:

Because dart_json_mapper_mobx 1.0.0 depends on mobx ^0.3.10 and no versions of dart_json_mapper_mobx match >1.0.0 <2.0.0, dart_json_mapper_mobx ^1.0.0 requires mobx ^0.3.10.

Would it be possible to update pubspec mobx version?

Thank you ;)

[k-paxian]

@felipeleon73 Thank you for letting me know about this.
Don't worry we'll make it happen, as soon as I'll reproduce this.

[felipeleon73]

A great ⭐️!

[felipeleon73]

The proposed solution, however, presents a problem.
The ObservableList is not serialized as a standard list, and this creates problems with any webapi:

{
 "mailingList": "[\"[email protected]\",\"[email protected]\",\"[email protected]\"]"
}

A better solution is to recognize the ObservableList as Iterable, modifying the file json_mapper.dart at lines 662-664 as follows:

bool get isIterable {
  return isList || isSet || typeName.indexOf ("ObservableList <") == 0;
}

In this way it is enough to use a valueDecorator:
JsonMapper.registerValueDecorator <ObservableList <String>> ((value) => ObservableList <String> .of (value.cast <String> ()));

   "mailingList": [
    "[email protected]",
    "[email protected]",
    "[email protected]"
   ]

Would it be possible to implement a way (perhaps a JSonProperty) to indicate that an object is Iterable without relying on the name?
Or better yet indicate that the object is a List, Set or Map?

[k-paxian]

@felipeleon73 Indeed, haven't noticed it myself. Thank you for vanishing it out.

Although, Thanks to your hint above I've got even better approach ironed out in my mind.

I'm gonna decouple typeInfo related code out of this library, this will opens the door for a range of specific "adapter" libraries one per each popular use case.

• MobX, https://github.com/k-paxian/dart-json-mapper-mobx
• Fixnum, https://pub.dev/packages/fixnum
• etc.

Each adapter library will contain a bundle of pre-configured:

• custom converters
• custom typeInfo decorators
• custom value decorators

So, in essence, you'll have to throw in another library dependency + 1 line of code,
and you are ready to jet 🚀

dependencies:
  dart_json_mapper: any
  dart_json_mapper_mobx: any

Thank you for Ideas!

[k-paxian]

@felipeleon73, It has nothing to do with MobX, it was an inheritance issue.

[felipeleon73]

Ok. Thanx!
Now it works with Lists ... how can I make mobx ObservableList work?
If I replace the line
List<String> mailingList = List<String>();
with the line
ObservableList<String> mailingList = ObservableList<String>();
serialization works correctly, but deserialization gives me an error:

Exception has occurred.
FormatException (FormatException: Unexpected character (at character 1)
[email protected]
^
)

I tried to register both a registerValueDecorator and a registerConverter but without success.

The question could also be: how to manage a custom implementation of a collection?

[k-paxian]

Quick answer is a custom converter for everything custom.
I'll try to put up an example for your case during the day

[k-paxian]

@felipeleon73
Ok, here is the code

import 'dart:convert' show JsonDecoder, JsonEncoder;
import 'package:mobx/mobx.dart';
import 'package:dart_json_mapper/annotations.dart';
import 'package:dart_json_mapper/converters.dart';
import 'package:dart_json_mapper/json_mapper.dart';

class ObservableListStringConverter implements ICustomConverter<dynamic> {
  const ObservableListStringConverter() : super();

  static JsonDecoder jsonDecoder = JsonDecoder();
  static JsonEncoder jsonEncoder = JsonEncoder();

  @override
  ObservableList<String> fromJSON(dynamic jsonValue,
          [JsonProperty jsonProperty]) =>
      ObservableList<String>.of((jsonValue is String)
          ? jsonDecoder.convert(jsonValue).cast<String>()
          : jsonValue);

  @override
  dynamic toJSON(dynamic object, [JsonProperty jsonProperty]) {
    final ObservableList<String> ols = object;
    return jsonEncoder.convert(ols.toList());
  }
}

@jsonSerializable
class MobX {
  ObservableList<String> mailingList = ObservableList<String>();

  MobX(this.mailingList);
}

    test("Custom ObservableList<String> converter", () {
      // given
      final String json =
          '''{"mailingList":"[\\"[email protected]\\",\\"[email protected]\\",\\"[email protected]\\"]"}''';
      MobX m = MobX(ObservableList<String>.of(
          ['[email protected]', '[email protected]', '[email protected]']));
      // when
      JsonMapper.registerConverter<ObservableList<String>>(
          ObservableListStringConverter());
      final String targetJson = JsonMapper.serialize(m, '');
      final MobX instance = JsonMapper.deserialize(targetJson);
      // then
      expect(targetJson, json);
      expect(instance, TypeMatcher<MobX>());
      expect(instance.mailingList, TypeMatcher<ObservableList<String>>());

      JsonMapper.registerConverter<ObservableList<String>>(defaultConverter);
    });

BTW, now you owe me a ⭐️

[felipeleon73]

Wow!!!
Great great approach!
And thanks to you for the great job!

[k-paxian]

@felipeleon73

Here you are https://github.com/k-paxian/dart-json-mapper-mobx, please check it out,
contributions are highly welcomed 👍

[k-paxian]

@1N50MN14 done.

[1N50MN14]

@k-paxian thank you!