Gradle 插件中的嵌套扩展

Question

我正在尝试在我的 gradle 插件中实现以下配置

music {
    artist {
        artistName = "artist1"
        album {
            albumName = "album1"
        }
    }
    artist {
        artistName = "artist2"
        album {
            albumName = "album1"
        }
        album {
            albumName = "album1"
        }
    }
}

这就是我目前所拥有的

open class MusicPlugin : Plugin<Project> {
    override fun apply(project: Project) {
        project.extensions.create("music", MusicPluginExtension::class.java)
    }
}

open class MusicPluginExtension @Inject constructor(val objectFactory: ObjectFactory) {
    val artists = objectFactory.domainObjectSet(Artist::class.java)

    fun artist(action: Action<in Artist>) {
        val artist = Artist(objectFactory)
        action.execute(artist)
        artists.add(artist)
    }
}

open class Artist @Inject constructor(objectFactory: ObjectFactory) {
    var artistName: String? = null
    val albums = objectFactory.domainObjectSet(Album::class.java)

    fun album(action: Action<in Album>) {
        val album = Album()
        action.execute(album)
        albums.add(album)
    }
}

open class Album() {
    var albumName: String? = null
}

当我将插件应用到项目时，我能够创建闭包，但是当我尝试为 Album 设置属性时失败（例如设置专辑名称）。这是我得到的错误：

FAILURE: Build failed with an exception.

* Where:
Build file '/Users/user/git/pluginTest/build.gradle' line: 19

* What went wrong:
A problem occurred evaluating root project 'pluginTest'.
> Could not set unknown property 'albumName' for object of type com.plugin.Artist.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

CONFIGURE FAILED in 84ms

我们将不胜感激。

Answer 1

或许你可以使用 Gradle 的NamedDomainObjectContainer。

interface MusicPluginExtension {
    // https://docs.gradle.org/current/userguide/custom_gradle_types.html#nameddomainobjectcontainer
    NamedDomainObjectContainer<Artist> getArtists()

    interface Artist {
        String getName()
        NamedDomainObjectContainer<Album> getAlbums()
        interface Album {
            String getName()
        }
    }
}

music {
    artists {
        register("artist1") {
            albums {
                register("album1"){}
                register("album2"){}
            }
        }
        register("artist2") {
            // ...
        }
    }
}

它适用于 1 级嵌套列表，也许它也适用于 2 级列表。