LTI Configuration & Post Messaging

Community Member

In the LTI configuration page, the section on launching without cookies ( it says the following:

In Step 2, instead of storing the state parameter in a cookie the tool should store it in Canvas's LTI Platform Storage using the lti.put_data postMessage. It's recommended that the key include the value (eg key: "state-1234", value: "1234") to avoid any collisions during multiple launches, and to make recovering the value easy.


However since we need to use the key to access the value in the first place, how are we supposed to have "the key include the value"? It seems that would defeat the whole need for this system in the first place, since we would already have the value that the postMessage is supposed to provide.