discourse-edx-lti

This is a Discourse plugin for using Discourse as a discussion forum in EdX courses.

It adds a Discourse AuthProvider that handles LTI authentication from EdX. This allows one-click navigation from an EdX course into the discussion forum. The login dialog also allows users to bounce back to the course, and Discourse admin users can sign in directly.

Alternately, you may be interested in a similar project using WordPress as a discussion forum for EdX courses.

Where has this been used?

• MIT: Design Thinking for Leading and Learning (course report)
• MIT: Launching Innovation in Schools, also on EdX Edge for a white-labeled small private online course

Learner user experience

1. Learner signs into EdX

2. Within EdX course, learner launches Discourse with LTI

3. The learner is authenticated with their EdX username

4. The Discourse instance is private

5. Login button links back to EdX course or allows admin login

Course author user experience

1. In Studio's Advanced Settings, enable LTI and add LTI passport (see EdX docs)

2. Add a new LTI widget

3. Set the LTI URL to /auth/lti/callback always

4. Set the LTI Custom Parameters to include ["url=/page-to-link-to"]

Note that this may be handled differently on edX versus an Open edX instance. See #22 for more.

5. Set the LTI Launch Target to open in a new window

Setup

Initial setup for new course forums

• This repository assumes you've already done this. See mit-teaching-systems-lab/discourse-for-moocsters for setup instructions for how we do this in our labs at MIT.

Install and setup this plugin

• The intent is that the site is private, and learners can only gain access by signing in through EdX and launching the site through LTI. Admin users sign into Discourse directly.
• To do this, the plugin sets some admin site settings related to users and login, which you can see in config/settings.yml. You can edit these in the Discourse Admin UI, but note that the interactions between these settings in different parts of the product are complex, and we don't recommend changing these defaults.
• Install this repository as a Discourse plugin (instructions)
• Rebuild container
• Test! Logout from your admin user, and click the Login button. You should see a Login with EdX button at the top of the Login dialog box (which won't work yet).

Discourse plugin setup

• Pick an id for the forum site, generate a consumer key and secret
• In Discourse, visit Admin -> Plugins -> discourse-edx-lti
• Set the LTI consumer key and secret, and the EdX course URL that has the LTI button to the forums.

EdX course setup

• In EdX Studio, visit Settings > Advanced settings
• Add "lti" and "lti_consumer" to Advanced Module List
• Add the forum site's id, consumer key and consumer secret to LTI Passports
• In Studio, add an LTI Consumer. Set the LTI id, and set the LTI URL to /auth/lti/callback on the Discourse forum domain. We typically set the LTI Launch Target to "New Window".
• For the LTI Consumer, make sure to set "Request users' username" and "Request user's email" to true. You may need to reach out to someone at EdX to enable this for your course.

Configure your Discourse forums

• Invite any other admin users
• Configure whatever else you like or add some more plugins or features!

Local development

You can develop with Vagrant (see Discourse docs). As you develop, clear the ERB cache, copy this repository to the plugins folder and restart Rails to see changes.

Example:

rm -rf tmp/cache && \
rm -rf ./plugins/discourse-edx-lti/ && \
rsync -av --exclude .git \
  ~/github/mit-teaching-systems-lab/discourse-edx-lti \
  ./plugins/ && \
vagrant ssh -c 'cd /vagrant && bundle exec rails s -b 0.0.0.0'

The plugin-third-party.js.erb file is what ultimately injects the JavaScript needed to show the new login button in the UI. In development mode, this file will be cached and won't updated if you are rebuilding the plugin on each change. You can touch it manually or just clear the ERB cache on each change (like above). See https://meta.discourse.org/t/tmp-cache-needs-to-be-manually-cleared-when-developing-plugins/17109 or sstephenson/sprockets#563 for other alternatives.