Consider adding Filer convenience methods back

[JakeWharton]

kapt compiles kt files generated from processors per comments on #93

[hotchemi]

I investigated a bit so let me share about it here.

• kapt3 actually supports .kt file generation and the destination is supposed to be generated/source/kaptKotlin/$sourceSetName(obtained by processingEnv.options["kapt.kotlin.generated"]), not generated/source/apt/$sourceSetName
  • KT-17883 Enhancement request - support annotation processing with generation of Kotlin source (rather than Java source)
  • KT-14070 Kapt3: kapt doesn't compile generated Kotlin files and doesn't use the "kapt.kotlin.generated" folder anymore
  • Kapt3: Support Kotlin sources generation (KT-14070)

[JorgeCastilloPrz]

Do you have any clue about how to write KotlinPoet generated classes to filer without using the not yet available KotlinPoet api method writeTo(filer) for it @hotchemi?

[JakeWharton]

Call toString(), write that as your file contents.

…

On Fri, Jul 21, 2017, 2:05 PM Jorge Castillo ***@***.***> wrote: Do you have any clue about how to write KotlinPoet generated classes to filer without using the not yet available KotlinPoet api method writeTo(filer) for it @hotchemi <https://github.com/hotchemi>? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#105 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAEEEYexRlYhhOkRQV43iSpSDFynv3U8ks5sQOhSgaJpZM4Nupmb> .

[hotchemi]

@JorgeCastilloPrz might be an off topic for this issue but right now we do as below and it works...the reason of replace("kaptKotlin", "kapt") is https://youtrack.jetbrains.com/issue/KT-19097. Hope it will help you.
https://github.com/hotchemi/PermissionsDispatcher/blob/master/processor/src/main/kotlin/permissions/dispatcher/processor/PermissionsProcessor.kt#L69

[JorgeCastilloPrz]

Im gonna add here another valid executable code sample. It's a repo I'm contributing to where we are also generating Kotlin files and compile time using KotlinPoet API and being able to referentiate those files from production code with no compile time errors: https://github.com/kategory/implicits-processor.

Interesting point here: I am just taking the kapt.kotlin.generated option path as it is, without replacing anything into it (related to @hotchemi's comment).

./gradlew clean :app:build to run and generate the files.

[codeprogression]

This is what worked for me (inspired by the kotlin-examples processor).

In the process method...

Get the target generated directory for kapt:

val kaptKotlinGeneratedDir = processingEnv.options["kapt.kotlin.generated"] ?:
  run {
      processingEnv.messager.printMessage(
        ERROR, 
        "Can't find the target directory for generated Kotlin files."
      )
      return false
  }

Create your file object:

val kotlinFile = KotlinFile.builder("com.example", "KotlinClass.kt")
  .addType(TypeSpec.classBuilder("KotlinClass").build())
  .build()

Write the file:

File(
  "$kaptKotlinGeneratedDir/${kotlinFile.packageName.replace(".", "/")}", 
  kotlinFile.fileName
).apply {
  parentFile.mkdirs()
  writeText(kotlinFile.toString())
}

[ZacSweers]

Definitely want this now that Kapt is adding support for gradle's incremental kapt support and using the same filer APIs

JetBrains/kotlin#2179

https://github.com/JetBrains/kotlin/pull/2179/files#diff-f5958ff916f88658e65a723fb591467dR142

I can take a swing at this this weekend

[Egorand]

Awesome, please do!