sbt-elm

A plugin for integrating the Elm compiler with Scala Build Tool and Play Framework. It is based on sbt-web and com.typesafe.sbt:js-engine.

Inspired from sbt-stylus, following this video.

Requirements

For this plugin to work you need to have the Elm compiler installed:

npm install -g elm

Usage in Play/Sbt

To use the plugin in Play, add this line to your project's plugins.sbt:

lazy val root = project.in(file(".")).dependsOn(sbtElm)
lazy val sbtElm = uri("https://github.com/sutiialex/sbt-elm.git")

Your build.sbt should also enable sbt-web plugins, i.e., it should contain the following line:

lazy val root = (project in file(".")).enablePlugins(SbtWeb)

You have to place your .elm files in src/main/assets/elm or in any of its subdirectories. If you have an elm project (as described by elm-make) with an elm-package.json, place it in src/main/assets/elm. The Elm compiler will run in that directory and will take that into consideration. The plugin will look for Main.elm in src/main/assets/elm or src/main/assets/elm/<path_to_subdir> and compile it. It will generate Main.js in target/web/public/main/elm or target/web/public/main/elm/<path_to_subdir>. The Elm compiler recursively builds all the modules imported by Main.elm.

Limitations

This plugin is presently only working with an engineType set to Node, e.g.:

set JsEngineKeys.engineType := JsEngineKeys.EngineType.Node

Building and Running Tests

Note that this step is not needed unless you want to tweak with the plugin.

If you have Elm installed, simply run:

sbt scripted

If you want to also install the Elm compiler, run in the root of the repository:

sh build.sh