Mobx.dart: mobx_codegen: allow generating toString method for Store class

[atsu85]

[pavanpodila]

Curious what would be the implementation of the toString() method ?

[atsu85]

smth simple like built_value (based on core state fields) would be good enough for me

[rrousselGit]

Interesting idea.
Flutter likes to have custom toString to make debugging easier.

For example, instead of MyClass, some widgets have a toString that looks like MyClass(foo: 42, bar: 'hello world')

See DiagnosticNode for more info

[atsu85]

that format would be ok as well, even tough personally i'd prefer built_value format (for development-time logging), because built_value formats properties on separate lines and excluded nulls :).
Ideally the format could be customized based on annotation parameter :)

[pavanpodila]

If you need a custom toString(), you can always add that to the concrete Store class:

class CustomStore extends _CustomStore with _$CustomStore {
  @override
  toString() { /* ... */ }
}

That said, we can add this to the backlog for generating a toString() implementation with the observables and computeds. Would that work ?

[atsu85]

@pavanpodila,

If you need a custom toString(), you can always add that to the concrete Store class:

yes, that's the manual approach I've used so far :)

we can add this to the backlog for generating a toString() implementation with the observables and computeds. Would that work ?

Yes, absolutely. I'd probably prefer just observables (core state) to be included in generated toString, but I see that some might prefer to include computeds as well. Ideally inclusion of computeds could be determined based on annotation parameter.

[pavanpodila]

@atsu85, do you want to take a stab at it? All changes are in the mobx_codegen package. I can help you tackle it and you will get to add your name to the esteemed list of contributors 🚀

[shyndman]

We could go even further, and make the generated class Diagnosticable (docs) if the store is marked with a @forFlutter annotation or something.

That way we'd get all sorts of debugging goodness in debuggers.

More significant project though.

[hawkbee1]

Wanted to try this "good first issue" but.. is this enhancement still needed ?
I see code has changed a lot since May and it looks like dispose method (#177) has been removed from Store (#334) .

[pavanpodila]

I think it's still worth having a useful toString(), so go all for it 👍. Yes, a few things have changed, but you can certainly add the toString() to the mixin.

[shyndman]

Maybe as an opt-in via the annotation?

@Store(generateToString: true)

[pavanpodila]

Ya let's make that a config object with that as the optional member, defaulting to false

[hawkbee1]

With no prior experience of mobx and its dependencies I have some questions :)
1/ Is it the right way to implement this ?
I've done a basic case on observables without annotation so far in order to figure how to do things:
Created a "ToStrings" template

import 'package:mobx_codegen/src/template/store.dart';

class ToStringTemplate {
  StoreTemplate storeTemplate;
  String name;

  @override
  String toString() => '_toString += \'$name: \${$name.toString()}, \';';
}

in store.dart I added a new Rows and added it to the storeBody

  final Rows<ObservableStreamTemplate> observableStreams = Rows();
  final Rows<ToStringTemplate> toStrings = Rows();

  String _actionControllerName;

  $actionControllerField

  $actions

  @override
  String toString() {
    var _toString = '';
    $toStrings
    return '{\$_toString}';
  }''';

In store_class_visitor.dart I add the new row during visitFieldElement

    _storeTemplate.observables.add(template);

    final toString = ToStringTemplate()
      ..storeTemplate = _storeTemplate
      ..name = element.name;

    _storeTemplate.toStrings.add(toString);

2/ What is the correct way to regenerate the _test.g.dart files because
flutter packages pub run build_runner build
messed-up something when dealing with the content of test/data

3/ which annotation ?
should we use a global annotation like
@Store(generateToString: true)
or let dev subscribe for the individual observables and computed he wants
@observable(generateToString: true) @computed(generateToString: true)

[pavanpodila]

Hello @hawkbee1, good try on your first attempt 👍

You won't need to use a generator for this part of the code. It will sit as part of the Store template that writes out the fields in a convenient way. You will have to generate the code for the toString method within this template

[pavanpodila]

Closing as its now merged with PR #414