Third-party Libraries That Depend On Dart_mappable Without Exporting Mappers Break Code Generation

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Third-party libraries that depend on dart_mappable without exporting mappers break code generation

Issue

When working with third-party libraries that depend on dart_mappable for generating model classes, it's not uncommon to encounter issues with code generation. This problem arises when the third-party library exports models but hides mappers to avoid polluting the autocomplete. This is a common practice, as seen in the discussion on the dart_mappable GitHub repository (https://github.com/schultek/dart_mappable/issues/91).

Let's assume we have a third-party package, package:some_package, that depends on dart_mappable to generate model classes. This package exports the models but hides the mappers to maintain a clean and organized codebase. Now, let's move to our app, where we create a class that uses those exported models in our own dart_mappable class. Unfortunately, the current implementation fails during code generation because the third-party library doesn't export *Mapper and *CopyWith classes. This is a problem because the models are annotated with @MappableClass(), which expects these classes to be available.

The issue here is that the third-party library is not exporting the necessary classes, but the models are still annotated with @MappableClass(), which expects these classes to be available. This leads to a failure in code generation, causing issues in our app.

Related repository

Unfortunately, there isn't a related repository that directly addresses this issue. However, the discussion on the dart_mappable GitHub repository (https://github.com/schultek/dart_mappable/issues/91) provides valuable insights into the problem and potential solutions.

Possible solution

One possible solution to this issue is to use custom mappers instead of generating new ones. This can be achieved by adding custom mappers to the @MappableClass() annotation. For example, we can use the following code:

@MappableClass(includeCustomMappers: [_SomeMapper()])

This allows us to provide custom mappers for the models, which can then be used instead of generating new ones. This approach seems feasible, especially if we have custom mappers available.

However, this solution requires us to have custom mappers available, which might not always be the case. In such situations, we need to explore other possible solutions.

Alternative solutions

If we don't have custom mappers available, we can explore other possible solutions to this issue. One approach is to modify the third-party library to export the necessary classes. This might require collaboration with the library maintainers or even forking the library to make the necessary changes.

Another approach is to use a different library for code generation, one that doesn't rely on the third-party library's mappers. This might require significant changes to our codebase, but it could provide a more stable and maintainable solution.

Conclusion

In conclusion, third-party libraries that depend on dart_mappable without exporting mappers can break code generation. This issue arises when the third-party library exports models but hides mappers, causing the @MappableClass() annotation to fail during code generation. While using custom mappers seems like a feasible solution, it requires us to have custom mappers available. In the absence of custom mappers, we need to explore alternative solutions, such as modifying the third-party library or using a different library for code generation.

Best practices

To avoid this issue, it's essential to follow best practices when working with third-party libraries that depend on dart_mappable. Here are some tips:

  • Always check the library's documentation to see if it exports the necessary classes.
  • If the library doesn't export the necessary classes, consider using custom mappers or exploring alternative solutions.
  • When using custom mappers, make sure to add them to the @MappableClass() annotation to ensure they are used instead of generating new ones.
  • If you're using a third-party library that depends on dart_mappable, consider contributing to the library's development to make it more compatible with dart_mappable.

By following these best practices, you can avoid the issue of third-party libraries breaking code generation and ensure a smooth development experience with dart_mappable.
Third-party libraries that depend on dart_mappable without exporting mappers break code generation: Q&A

Q: What is the issue with third-party libraries that depend on dart_mappable without exporting mappers?

A: The issue arises when the third-party library exports models but hides mappers to avoid polluting the autocomplete. This causes the @MappableClass() annotation to fail during code generation because the models are annotated with @MappableClass(), which expects the mappers to be available.

Q: What are the consequences of this issue?

A: The consequences of this issue are that code generation fails, causing issues in the app. This can lead to errors, bugs, and a poor user experience.

Q: How can I identify if a third-party library is causing this issue?

A: You can identify if a third-party library is causing this issue by checking the library's documentation to see if it exports the necessary classes. If the library doesn't export the necessary classes, but the models are annotated with @MappableClass(), then it's likely causing this issue.

Q: What are some possible solutions to this issue?

A: Some possible solutions to this issue are:

  • Using custom mappers instead of generating new ones.
  • Modifying the third-party library to export the necessary classes.
  • Using a different library for code generation.

Q: How can I use custom mappers instead of generating new ones?

A: You can use custom mappers instead of generating new ones by adding custom mappers to the @MappableClass() annotation. For example:

@MappableClass(includeCustomMappers: [_SomeMapper()])

This allows you to provide custom mappers for the models, which can then be used instead of generating new ones.

Q: What are some best practices to avoid this issue?

A: Some best practices to avoid this issue are:

  • Always check the library's documentation to see if it exports the necessary classes.
  • If the library doesn't export the necessary classes, consider using custom mappers or exploring alternative solutions.
  • When using custom mappers, make sure to add them to the @MappableClass() annotation to ensure they are used instead of generating new ones.
  • If you're using a third-party library that depends on dart_mappable, consider contributing to the library's development to make it more compatible with dart_mappable.

Q: Can I modify the third-party library to export the necessary classes?

A: Yes, you can modify the third-party library to export the necessary classes. However, this might require collaboration with the library maintainers or even forking the library to make the necessary changes.

Q: What are some alternative libraries for code generation that I can use?

A: Some alternative libraries for code generation that you can use are:

  • build_runner
  • freezed
  • json_serializable

Q: How can I contribute to the development of a third-party library to make it more compatible with dart_mappable?

A: You can contribute to the development of a third-party library to make it more compatible with dart_mappable by:

  • Submitting pull requests with changes to the library's code.
  • Participating in the library's issue tracker to discuss potential changes.
  • Collaborating with the library maintainers to make the necessary changes.

By following these best practices and exploring alternative solutions, you can avoid the issue of third-party libraries breaking code generation and ensure a smooth development experience with dart_mappable.