Add support for multiple package project

[remonh87]

Is your feature request related to a problem? Please describe.
This library really works great and generates a lot of boiler plate code. Unfortunately it works perfect for a single package app but does not support monorepo. For example:
I have a package called app_ui and my translation assets are located in: lib/app_ui/translations. In the pubspec.yaml I declare my assets like: packages/app_ui/i18n/en.json . My main is located in the app_main package.
The rosetta generator is able to find my file, can generate the code, but does not generate the proper code for loading the asset. When I start the app it crashes because rootbundle cannot load the translated file.

Describe the solution you'd like
Add support for the package name, for example:
@Stone(path: 'lib/i18n', package: "app_ui") class Translation with _$TranslationHelper { ... }

Based on this the rosetta_generator can generate the following snippet in the translationhelper:
var jsonStr = await rootBundle.loadString("packages/app_ui/i18n/${locale.languageCode}.json");

[agta1991]

This sounds like a great feature for the next version.

Can you provide a simple detailed project setup, where the described issue is reproducible? I got a bit confused when trying to declare the assets in the multi package setup.

[remonh87]

I have an example setup at my github: https://github.com/remonh87/multi-package-example-flutter

[agta1991]

So if I get it correctly, you have an app packages which uses a separate app_ui flutter package, which contains the translation json-s and the @Stone-ed class.
Did you declare and run the generator for the app or the ui package?

[remonh87]

the generator is declared and run within the ui package

[agta1991]

Awesome! I checked a few configurations to get a bigger picture about the problem.

Tomorrow, I will have some time to add the new functionality to the lib.

[agta1991]

As described, v0.1.2 release introduces the package attribute to declare the bundle package.
It's published to pub so you can try out the new API.

[remonh87]

@agta1991 thanks for picking this up quickly. I did test it with the latest package but still see a small issue in the generated code of the helper: you include the lib folder in the call to rootbundle. This should not be the case when you want to load the asset from a package.

Example
var jsonStr = await rootBundle.loadString('packages/app_ui/lib/i18n/${locale.languageCode}.json');

should become:
var jsonStr = await rootBundle.loadString('packages/app_ui/i18n/${locale.languageCode}.json');

[agta1991]

This brings back another problem. The generator should know the path of the json in the builder host's file system during the build phase, but also it must know the package path which will be bundled.
In the above case it is different. I used it in separate folders in my sandbox project, which resulted in matching host and bundled paths. Moving the i18n folder up into the parent of lib will result in this case.

As I saw in your example project setup, the i18n folder is under lib. And you declare it as

flutter:
  assets:
  - packages/app_ui/i18n/en.json

But if you put it next to lib, and declare it as:

flutter:
  assets:
  - i18n/en.json

The compiler will still bundle it as packages/app_ui/i18n/en.json but it will have a matching path "i18n/en.json" with the host system.

Is it critical to support mixing the asset files with the source files in lib?

[spkersten]

@agta1991 I don't think it's critical for us. Reading the docs it seems like putting them into the root of the package is actually the right way and putting them into lib was a misunderstanding by us.

[remonh87]

It is indeed not critical so issue can be closed.

[remonh87]

I used the suggested structure but then the rosetta generator cannot find the file and won't generate the keys: see for example https://github.com/remonh87/multi-package-example-flutter .