Kotlin Coroutines Support

[cortinico]

This is an initial PR for supporting another template to generate Kotlin-coroutines code.
I'd love to get some early feedback from @macisamuele before I continue working on this to decide how we want to setup the project.

I'm not a big fan of copying all the .mustache files over, so we should probably re-organize them in subfolders?

What's missing:

• Tests
• Updated the readme
• Add a kotlin-coroutines to the samples

[macisamuele]

@cortinico we already discussed about the PR in person, but it would be better to keep a trace over here as well.

I do like the idea of having a new "template" that allows generation of coroutine based code.
Duplicating code and templates as provided in this PR could be a possibility but I do expect higher maintenance costs.

What if we do have a generic KotlinGenerator that will be extended by two independent generators (ie: KotlinRxJavaGenerator and KotlinCoroutineGenerator)?
By doing so we can ensure that all the kotlin specific details are defined once and reused.

The needed additions would be:

• having a method that given the output type generates the appropriate string (ie. Type -> Single<Type>|Completable|Defer<Type>|Type according to the case)
• templating the method modifiers to allow injection of suspend keyword in the API methods generation

NOTE: Doing something like this will then require a major release as the original currently existing template would not be usable anymore

[cortinico]

After some discussion with @macisamuele we feel more comfortable pushing this to a future release

[chathudan]

@cortinico are you planning to release this sooner?

[cortinico]

@cortinico are you planning to release this sooner?

I'm currently looking for feedback on this. I would be interested in understanding if you're planning to use this modified template.
Adding coroutines support is quite straightforward, but it's yet another template that we have to maintain. Having active users that are the template is a valid reason to spend effort on it.

Regarding the timeline, ideally we can manage to have this merged and have a new release by the end of November.

[StepanMynarik]

I would love to use this, but I need it ASAP. Currently I'm using Swagger Codegen which has Kotlin coroutine support already.
I can't, however, force it to use ThreeTenABP LocalDate type instead of string for date fields. And it seems it will not be resolved in the foreseeable future :(

Is there a way to generate code with this pull request? I don't know how to download entire repository, patched with a specific PR out of GitHub. Also this codegen is used through Gradle I noticed. That makes it even more difficult for me then. At least a believe so. I'm new to Android Studio, Gradle and all, sorry.

Thanks

[cortinico]

Hi all, please find a production-ready version of the coroutines support. Other than @macisamuele 's feedback I'd love to get an ack from either @redwarp or @filipemp.

I've took a different approach from the first commit. We now don't need to clone the entire .mustache file hierarchy.

@cortinico are you planning to release this sooner?

This will be in the upcoming release @chathudan, unless we find a major blocker during the review.

I would love to use this, but I need it ASAP.

@StevenKek apologize for the delay but I took a 2 months sabbatical and I haven't really checked my Github notifications :/ Ideally we're going to ship this soon and you'll have it bundled in the upcoming release.

Is there a way to generate code with this pull request?

You could checkout the fork and install the gradle plugin inside your maven local. It's doable but a bit complicated to setup. If you're not in a hurry, I advice you wait for the upcoming release.

[macisamuele]

Very nice approach to the problem.
Reduce template duplication while preserving consistency and expandability!

🚢

[cortinico]

Very nice approach to the problem.
Reduce template duplication while preserving consistency and expandability!

Awesome! Thanks for the approval.
Let's wait for an ack from either @redwarp or @filipemp