Content Invocation protocols

This page describes the content invocation protocols supported by ADAPT²

Why Content Invocation?

A content invocation protocol allows two online learning systems to work together in supporting learners. With this protocol, a host system, such as a learning portal, a learning management system, or a personalized learning interface) can activate an independent client system while also passing a range of important parameters to it, most importantly, information about the user and group who will work with the client system, and the user target. The target might indicate a specific activity that the client system will need to launch for the user, while the information about the user and group enables the client system to customize its interaction with the user. The information about the user and the target is also important to log the information about the user interaction with the tool.

When ADAPT² was originally developed in 2002, it implemented its own content invocation protocol, since no other protocols supported personalized invocation of external learning content at that time. As other protocols gradually evolved, an increasing volume of interactive learning objects that implemented these protocols was developed. To leverage this content, ADAPT² components now support other content invocation protocols.

ADAPT² protocol for user authentication and activity invocation

ADAPT² content invocation protocol is the "native" protocol of ADAPT² infrastructure. This protocol is adopted by all ADAPT² tools developed by our teams and by many content servers developers by our collaborators. It regulates how user and resource identities is transferred from application to application via the following HTTP parameters (see ADAPT² Parameter Naming Conventions)

• usr - user identifier, usually login (mandatory)
• grp - group identifier (mandatory), just like a user identifier, but for a group of users (class, research team)
• sid - session identifier (optional), usually 5 character string each application makes a choice whether and how to come up with this parameter (e.g. truncate | Apache Tomcat session id to last 5 characters)
• act - id of the resource (mandatory), each application maintains its own vocabulary of resource ids
• sub - if a resource is a collection of multiple resources/steps, then a sub-resource id is supplied to call a specific sub-resource or step (optional)
• svc – service parameter – any character string that can be used to store system state, should not contain ? (question mark), & (ampersand), : (colon), and / (backward slash); however all those symbols can be encoded using Java URLEncoder class that maps them to %XX; service parameter (optional)
• cid - course id that defines the course in which this content is being requested (optional). This parameter is different than grp because there could be multiple groups within a single course.

ADAPT² content invocation protocol is "stackable". It could be used by a learning portal to call a specific learning object for the user to work with, but can be also used to call a specific personalized service or shell to assist the user. By receiving information about the user, the service could call a specific learning content for this user, passing down the same parameters.

Example invocation requests

Below, there is an example invocation request to access a learning content using ADAPT² content invocation protocol.

Request URL Format:

http|https://<content_url>?app=<application_id> &act=<learning_object> &sub=<learning_object_step> &usr=<user> &gpr=<group> &sid=<session_id> &svc=<service_parameters> & cid=<course_id>

Check above for more details about the URL parameters used in this request. The content URL defines where this content is being hosted and could contain content-specific parameters. ADAPT² URL parameters should be appended if there are any content-specific URL parameters.

For example, to invoke a PCRS coding activity using this protocol, the following URL can be used:

https://PCRS_URL?act=PCRS&sub=rectangle_perimeter&svc=masterygrids&grp=groupid&usr=userid&sid=sessionid&cid=courseid

Here, PCRS_URL should be replaced with an actual URL obtained from the content provider.