Elm Client Overview

For pretty much any operation this plugin you support you need an elm client connection. An elm client connection

is a small node process that the plugin typically will spawn automatically for any action that requires a elm client.

When the elm-client starts it;

• Opens an elm-repl
• Starts (and listens) to elm-reactor
• Downloads packages if necessary and parses all relevant Elm code to AST representations
• Starts a listener process for changes to Elm files and packages
• Listens for commands from light table (eval, docs, autocompletions etc)

You may also manually connect to an elm project using the connect bar in Light Table

• Invoke the command: Connect: Add Connection

• Select Elm from the list of client types

• If all goes well you will get a confirmation in the status bar that the project is connected

• To disconnect

  • Invoke the command Connect: Show connect bar

  • Find the project in the list and click disconnect

The client connections are named after the the directory containing the elm-package.json

Elm Project

In the future the plugin might add support for geting started with just a simple .elm file, but you very quickly

end up having to add some config especially a elm-package.json. So as mentioned in the preconditions, you will need one.

How does elm-light determine the project ?

Say you have a project with the following structure

/home/myuser/projects/hello-elm/elm-package.json````/home/myuser/projects/hello-elm/hello.elm````/home/myuser/projects/hello-elm/src/util.elm

• If you start of with evaluating hello.elm, the plugin will start looking for a elm-package.json in the same directory

  as the hello.elm file resides. So the elm client will use `\/home\/myuser\/projects\/hello-elm` as root path and the project assumed to be `hello-elm`

• If you start of with evaluating util.elm, it will start looking for a `elm-package.json` in the `src` folder, since not finding one it will try the parent directory (and recurse until one found or none can be found).

• Hence the root path and project name will be the same

• If you (with the elm-client still running) later add a .elm file anywhere below `\/home\/myuser\/projects\/hello-elm` and eval or lint (or whatever) on it, the plugin will assume it belongs to the same elm-client and use that.