django-lti

A Django reusable app providing support for LTI Advantage.

Installation

Install using pip.

pip install django-lti

Setup

Start by adding lti_tool to your project's INSTALLED_APPS.

INSTALLED_APPS = [
    ...
    "lti_tool",
]

Then, add lti_tool.middleware.LtiLaunchMiddleware to the MIDDLEWARE setting. It's important to list the LtiLaunchMiddleware after SessionMiddleware.

MIDDLEWARE = [
    ...
    'django.contrib.sessions.middleware.SessionMiddleware',
    'lti_tool.middleware.LtiLaunchMiddleware',
]

Finally, run migrations to initialize the needed database tables.

python manage.py migrate lti_tool

Usage

Adding JWKS and OIDC initiation URLs

To allow LTI platforms to retrieve a JWKS and initiate a launch, add paths for lti_tool.views.jwks and lti_tool.views.OIDCLoginInitView to urls.py

...

from lti_tool.views import jwks, OIDCLoginInitView

urlpatterns = [
    path(".well-known/jwks.json", jwks, name="jwks"),
    path("init/<uuid:registration_uuid>/", OIDCLoginInitView.as_view(), name="init"),
]

Generating and rotating keys

Keys for the JWKS can be generated using the rotate_keys management command.

python manage.py rotate_keys

Registering an LTI platform

An LTI platform can be registered through the Django admin, or using a custom interface.

Handling an LTI launch

To handle the LTI launch, inherit from LtiLaunchBaseView and implement the handler methods for the types of LTI message types that the application supports.

class ApplicationLaunchView(LtiLaunchBaseView):

    def handle_resource_launch(self, request, lti_launch):
        ...  # Required. Typically redirects the users to the appropriate page.

    def handle_deep_linking_launch(self, request, lti_launch):
        ...  # Optional.

    def handle_submission_review_launch(self, request, lti_launch):
        ...  # Optional.

    def handle_data_privacy_launch(self, request, lti_launch):
        ...  # Optional.

Each handler method receives the request, as well as a LtiLaunch object.

When a session is initiated by an LTI launch, data about the launch is available from the request at request.lti_launch as an LtiLaunch object. During a non-LTI session request.lti_launch will refer to an AbsentLtiLaunch object.

It is possible to distinguish between LtiLaunch and AbsentLtiLaunch objects using the .is_present and .is_absent properties.