CODEWITHSUNDEEP
kotlinkaptkotlinpoet
Mark Dappollone
Mark Dappollone

Reputation: 1530

How to use KotlinPoet to get correct TypeName for PropertySpec

Using KotlinPoet, in order to generate a PropertySpec for adding properties to classes and constructors, you need a TypeName object.

The TypeMirror.asTypeName() KotlinPoet function is deprecated, because it won't always work correctly for Kotlin types.

But I can't find a single example of how to get a correct TypeName for a Kotlin class (e.g. kotlin.String) using the kotlinpoet-metadata APIs, the way the deprecation message says.

The docs for kotlinpoet-metadata APIs also seem completely broken (go to https://square.github.io/kotlinpoet/interop-kotlinx-metadata/#interop-with-kotlinx-metadata and click anything under the APIs section)

Does anyone have an example of how to replace TypeMirror.asTypeName() with some kotlinpoet-metadata code to get a TypeName, so that I can create a PropertySpec?

Upvotes: 8

Views: 1754

Answers (2)

hlidka
hlidka

Reputation: 2365

I have found a way to get the TypeName of a TypeElement in my AbstractProcessor, thanks to having access to its processingEnv:

val kmClass = (typeElement.kotlinClassMetadata() as KotlinClassMetadata.Class).toKmClass()
val elementName: TypeName = ClassName(processingEnv.elementUtils.getPackageOf(typeElement).toString(), kmClass.name.substringAfterLast("/"))

It should also be doable without processingEnv by splitting the kmClass.name manually.

Upvotes: 0

Boon
Boon

Reputation: 2151

Not very sure if this aligns with the intention of the deprecation message, but this is what I got it to work.

I first had to add kotlinpoet-metadata-specs.

implementation("com.squareup:kotlinpoet:1.7.1")
implementation("com.squareup:kotlinpoet-metadata:1.7.1")
implementation("com.squareup:kotlinpoet-metadata-specs:1.7.1")

Then use a util method from com.squareup.kotlinpoet.metadata.specs.internal.ClassInspectorUtil to create className.

val packageName = getPackage(element).qualifiedName.toString()
val typeMetadata = element.getAnnotation(Metadata::class.java)
val kmClass = typeMetadata.toImmutableKmClass()
val className = ClassInspectorUtil.createClassName(kmClass.name)

then use

val funSpec = FunSpec.builder("allNullableSet")
                     .receiver(className)
                     .returns(Boolean::class.java)
                     .addStatement(statement)
                     .build()

Upvotes: 3

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