A sbt-plugin and mill-plugin to generate scala code for web-components (custom-elements.json).

Heavily inspired by laminar-shoelace-components. We aim to provide a more generic way to generate scala code for any web framework in scala.

custom-elements.json + template => generate scala code

The plugin can be configured to parse a list of custom-elements.json files defining web-components. You can provide a custom scalate template to generate scala code out of this information (webcodegen.Template.File(file)). Or you can chose an existing template that is included with the plugin (webcodegen.Template.Outwatch).

In project/plugins.sbt:

addSbtPlugin("com.github.cornerman" % "sbt-web-components-codegen" % "0.1.3")

In build.sbt:

lazy val web = project
  .enablePlugins(webcodegen.plugin.WebComponentsCodegenPlugin)
  .settings(
    // The custom-element.json files to be processed
    webcodegenCustomElementsJson := Map(
      "some-library" -> file("some/custom-elements.json"),
    )
    // The templates to be used in the code generator
    webcodegenTemplates := Seq(
      webcodegen.Template.Outwatch,
      webcodegen.Template.File(file("path/to/file.ssp")),
      webcodegen.Template.File(file("path/to/file.mustache")),
    )
  )

In build.sc:

import mill._, scalalib._
import $ivy.`com.github.cornerman::mill-web-components-codegen:0.1.3`, webcodegen.plugin.WebComponentsCodegenModule

object backend extends ScalaModule with WebComponentsCodegenModule {
  // The custom-element.json files to be processed
  def webcodegenCustomElementsJson = Map(
      "some-library" -> os.pwd / "custom-elements.json",
  )
  // The templates to be used in the code generator
  def webcodegenTemplates = Seq(
      webcodegen.Template.Outwatch,
      webcodegen.Template.File(os.pwd / "file.ssp"),
      webcodegen.Template.File(os.pwd / "file.mustache"),
  )
}

Use coursier to launch the CLI for generating code:

cs launch com.github.cornerman:scala-web-components-codegen-cli_2.13:0.1.3 -- --custom-elements-name shoelace --custom-elements-json "node_modules/@shoelace-style/shoelace/dist/custom-elements.json" --out-dir generated-code --template-outwatch --scala-version "3.0.0"

Templates can be configured by setting webcodegenTemplates.

We are using scalate for templates, so you can use anything that is supported there (e.g. mustache or ssp) - the converter will be picked according to the file extension of the provided template file. Check the scalate user guide for more details.

A template is called for each web-component found, and is passed an instance of webcodegen.WebComponent.Element (variable name element) which contains all the extracted information. You can see the declaration in the first line of each ssp template.

See existing templates for details.