External Tool Link Selector

The methods outlined here use resource selection, which is deprecated.

See the Content Item documentation to design a tool that can add content to the RCE in a way that conforms with the most up to date IMS LTI standard.

An extension to standard LTI, external tools can be configured to allow selecting custom links to be added to modules or used for external tool assignments. When a tool is configured, if the user goes to add a link to a module or select a link for an external tool assignment, they'll see the tool with a special "find" icon on it. Clicking this tool will pop up a dialog and load the external tool inline. The tool should direct users to select or build a resource. The tool will then redirect the user to the LTI success URL with some additional parameters. Canvas will use these parameters to create custom URL that will be used as the link.

URLs returned in this manner will not circumvent the standard LTI URL/domain checking procedure, which is important to remember when returning URLs to add to the course. In general, it is best to make the these type of tools as domain-matching tool and only return URLs whose domain matches the tool's specified domain.

When tools are loaded as link selectors, Canvas sends an additional parameter to notify the tool of the directive, ext_content_return_types=select_link. When a tool receives this directive, it means Canvas is expecting the tool to redirect the user to the LTI success URL with some specific additional parameters. These additional parameters tell Canvas what URL to select, as listed below. Remember to URL encode parameter values such as url.

Possible Redirect Parameters

return_type=lti_launch_url (required)
url=<url> this is URL that will be used to load the external tool (required)
text=<text> this is the suggested text for the inserted link. Highlighted content will be overwritten by this value. (required)
title=<text> this is used as the 'title' attribute of the inserted external tool link (optional)

examples:

If the launch_presentation_return_url were http://www.example.com/done, possible return URLs could include:

Settings

All of these settings are configurable for the "resource_selection" placement in the tool configuration