Build rich text editors in Elm

elm-package install rupertlssmith/rte-toolkit-patch 1.0.0


Clone of mweiss/elm-rte-toolkit to work around Elm 0.19.1 restriction.

This is a published clone of mweiss/elm-rte-toolkit to work around Elm 0.19.1 restriction in its elm.json. This version will build on Elm 0.19.0.

Prefer the original where possible.

Rich Text Editor Toolkit

Create rich text editors in Elm.

Rich Text Editor Toolkit is an open source project to make cross platform editors on the web. This package treats contenteditable as an I/O device, and uses browser events and mutation observers to detect changes and update itself. The editor's model is defined and validated by a programmable specification that allows you to create a custom tailored editor that fits your needs.

This package was heavily inspired by other rich text editor frameworks like ProseMirror, Trix, and DraftJS.


Getting started

This package requires some webcomponents to get started.

If you can support ES6, you can include js/elmEditor.js in your project and import it along with your favorite webcomponent polyfill.

import '@webcomponents/webcomponentsjs/webcomponents-bundle.js'
import 'elmEditor.js'

The demo in this repository does it that way.

However, if you want to use a bundler and polyfill, you can import your favorite polyfill and import the npm package that has this repository's js compiled to es5 with npm, e.g:

npm install --save @webcomponents/webcomponentsjs
npm install --save elm-rte-toolkit

And in your javascript, you can import it like so:

import '@webcomponents/webcomponentsjs/webcomponents-bundle.js'
import '@webcomponents/webcomponentsjs/custom-elements-es5-adapter.js'
import 'elm-rte-toolkit';

Starting CSS

You can use whatever styles you want for the editor, but you may want to use the following as a jumping off point. Most importantly, you'll probably want white-space: pre-wrap; to distinguish between multiple spaces:

.rte-main {
    text-align: left;
    outline: none;
    user-select: text;
    -webkit-user-select: text;
    white-space: pre-wrap;
    word-wrap: break-word;

.rte-hide-caret {
    caret-color: transparent;


This package is open-source software, freely distributable under the terms of an BSD-3-Clause license. The source code is hosted on GitHub.

Contributions in the form of bug reports, pull requests, or thoughtful discussions in the GitHub issue tracker are welcome. Please see the Code of Conduct for our pledge to contributors.

Running the demo

The demo was bootstrapped with create-elm-app. See that repository for instructions of how to install the elm-app command.

To debug the demo locally, run the following from the repository's root directory:

cd demo
elm-app start

To build the demo, run the following from the repository's root directory:

cd demo

The demo is hosted with gh-pages, so to update the demo, please update the gh-pages branch with the latest build.

Running tests

For now, because of mysterious package issues with elm-test I don't want to debug, tests for the package are in the demo app folder. To run tests:

cd demo