JteModel.kt

package common

import gg.jte.TemplateEngine
import gg.jte.TemplateOutput

// you need to define this interface yourself. It needs to have the render method,
// and you can add other methods if you want
interface JteModel {
	fun render(engine: TemplateEngine, output: TemplateOutput)
}

// JteModelPlugin then generates code that looks like this
class main(
	val title: String,
	val description: String,
	val content: gg.jte.Content,
	) : common.JteModel {

	override fun render(engine: TemplateEngine, output: TemplateOutput) {
		engine.render("pages/main.jte", mapOf(
			"title" to title,
			"description" to description,
			"content" to content,
		), output)
	}
}

class aboutUs(
	) : common.JteModel {

	override fun render(engine: TemplateEngine, output: TemplateOutput) {
		engine.render("pages/Marketing/aboutUs.jte", mapOf(
		), output)
	}
}

// to pass data into the templates without arguments, you can use thread locals like this
object JteCtx {
	class Module : Jooby.Module {
		override fun configure(env: Env, conf: Config, binder: Binder) {
			Multibinder.newSetBinder(binder, org.jooby.Renderer::class.java)
					.addBinding()
					.toInstance(Jte())
		}
	}

	class Jte : org.jooby.Renderer {
		override fun render(value: Any, ctx: org.jooby.Renderer.Context) {
			if (value is JteModel) {
				locals.set(ctx.locals())

				val output = Utf8ByteOutput()
				val codeResolver = DirectoryCodeResolver(Paths.get("src/main/jte"))
				val templateEngine = TemplateEngine.create(codeResolver, ContentType.Html)
				value.render(templateEngine, output)

				val buffer = ByteArrayOutputStream()
				output.writeTo { bytes, offset, length -> buffer.write(bytes, offset, length) }
				ctx.type(MediaType.html).length(output.contentLength.toLong()).send(buffer.toByteArray())
			}
		}
	}

	val locals = ThreadLocal.withInitial { mapOf<String, Any>() }

	@JvmStatic
	fun fp(input: String): String {
		val fingerprinted = locals.get().get(CustomAssets._PERMANENT) as Map<String, String>?
		return if (fingerprinted == null) {
			CustomAssets.ASSETS_FINGERPRINT_RAW + input
		} else {
			val fp = fingerprinted[input] ?: throw NoSuchElementException("No such fingerprinted $input")
			CustomAssets.ASSETS + "/permanent/" + fp
		}
	}

	@JvmStatic
	fun style(fileset: String): RockerRaw {
		var threadLocals = locals.get()
		val linkTags =
				(threadLocals.get(fileset + CustomAssets._STYLES)
						?: throw NoSuchElementException(
								"No such styles $fileset, available: $threadLocals.keys"))
						as String
		return RockerRaw.raw(linkTags)
	}

	@JvmStatic
	fun script(fileset: String): RockerRaw {
		var threadLocals = locals.get()
		val linkTags =
				(threadLocals.get(fileset + CustomAssets._SCRIPTS)
						?: throw NoSuchElementException(
								"No such scripts $fileset, available: ${threadLocals.keys}"))
						as String
		return RockerRaw.raw(linkTags)
	}
}

This is example output from JteModelPlugin which is listed at this gist.

casid/jte#205 for further context.