Kotlin support for target / source in @Mapping and @ValueMapping

[aRusenov]

Currently the plugin only works in .java @Mapper classes (though it offers completions for source and target when referencing Kotlin classes as well!). It seems as if the plugin is simply not triggered in .kt mappers, but it works otherwise fine with Kotlin.

Kotlin Mapper interface:

Java Mapper interface:

In both cases the DTO and model are Kotlin classes.

Versions used:

• Kotlin 1.1.51
• mapstruct 1.2.0.final
• IntelliJ Community Edition 2017.2.3

[filiphr]

The plugin uses the default way of accessing the annotations in elements. I have to dig in to understand how it works within kotlin. If someone has some idea or knows what exactly needs to be done I am looking forward to your help 😄

[lppedd]

@filiphr I can have a look at it, I want to keep using Kotlin and completion is always helpful. Could you maybe point to a starting class?

[filiphr]

One starting point would be Handling code from the IntelliJ SDK documentation.

As for the plugin some starting classes that you would need to look are:

<psi.referenceContributor language="JAVA" implementation="org.mapstruct.intellij.codeinsight.references.MapstructReferenceContributor" />
<methodReferencesSearch implementation="org.mapstruct.intellij.search.MappingMethodUsagesSearcher" />
<renameHandler implementation="org.mapstruct.intellij.rename.MapstructSourceTargetParameterRenameHandler"/>

The way the completion works is by providing references through a reference contributor. The MapstructReferenceContributor is the one that registers the contributors. I think that you can actually use the same implementation, but you would need to provide different MapstructElementUtils that would be able to get the PsiElement from the kotlin plugin.

The MappingMethodUsagesSearcher is something I needed to add for find usages to work. Maybe it would work ootb with Kotlin, as I don't see anything specific to Java in there.

The MapstructSourceTargetParameterRenameHandler is something I needed to add for renaming to work properly, I think that we can reuse that as well, but we would need to find a neat way to pass MAPPING_SOURCE_OR_TARGET as the Kotlin plugin dependency should be optional.

There are some tests, that might guide you and that you might be able to utilise for debugging

[greenarr0w]

Are there any news on this issue? It would be very nice to have kotlin support.

[filiphr]

@greenarr0w I haven't had a lot of time to look into this. If someone from the community would like to step up and help with this it would be much appreciated.

[filiphr]

Done in 41dd190 and 1119db7

thanks @ifrankwang for your work on this.