ApiCanvas

API hooks for canvas

The following API hooks are supported for Canvas instances:

• User ID
• Course Groups service
• Membership service (including group information)
  • Resource link level
  • Context level

The implementation of the Membership service is more equivalent to the unofficial Memberships service extension which includes support for passing group membership data as well as enrolments.

The hooks should be registered as follows:

use ceLTIc\LTI\ApiHook\ApiHook;
use ceLTIc\LTI\Tool;
use ceLTIc\LTI\Context;
use ceLTIc\LTI\ResourceLink;

Tool::registerApiHook(ApiHook::$USER_ID_HOOK, 'canvas', 'ceLTIc\LTI\ApiHook\canvas\CanvasApiTool');
Context::registerApiHook(ApiHook::$GROUPS_SERVICE_HOOK, 'canvas', 'ceLTIc\LTI\ApiHook\canvas\CanvasApiContext');
Context::registerApiHook(ApiHook::$MEMBERSHIPS_SERVICE_HOOK, 'canvas', 'ceLTIc\LTI\ApiHook\canvas\CanvasApiContext');
ResourceLink::registerApiHook(ApiHook::$MEMBERSHIPS_SERVICE_HOOK, 'canvas', 'ceLTIc\LTI\ApiHook\canvas\CanvasApiResourceLink');

Configuration options

The following configuration options are supported:

Name	Required?	Description	Example
canvas.domain	Yes	The domain for the Canvas instance	myinst.instructure.com
canvas.token	Yes	The web service access token authorising API requests	12345~jhFJ9ao9GSBQDt5JIrGw3tfOEKzM1x8FQDI4k0SfTVrUzEQzCTUtoRwsH6XHgRZr
canvas.group_set_prefix	No	A prefix which a grouping name must match before it is considered to be included in the results	Group
canvas.per_page	No	Maximum number of records to be requested per message. The default is 50; use a value of 0 to remove the limit.	100

These configuration options should be saved in the settings area of the platform record; for example:

$platform->setSetting('canvas.per_page', '75');

The options must be specified for each Canvas instance defined within the tool; at least the domain and access token will be different for each.

When using LTI 1.3, the Canvas course ID must also be explicitly passed as a custom parameter:

canvas_course_id=$Canvas.course.id

(This parameter is automatically included by Canvas for connections using earlier releases of LTI.)

Prerequisites

The API hook uses the Canvas web services which are documented on the /doc/api/live page of each site. The Canvas instance must be configured to authorise the access from the tool. This involves generating an access token for a user with sufficient privileges to access the enrolments for each course (see the Settings page for the user).

Limitations

The current implementation has the following limitations:

1. The roles returned for each user do not include any administrator roles which may apply to the user and would be included in an LTI message.
2. The value of the lis_result_sourcedid parameter is not included.