Hi to all,
The plugin needs to verify that the user exists in order to know if it is necessary to create or not based on the LTI parameters received. LTI states that the tool should not use email as a primary key. So, it is necessary to use a key based on the parameters received. This LTI plugin uses the combination of the LTI parameters: oauth_consumer_key + ':' + user_id as recommended by LTI.
The field Name (which is the one that is displayed) is used to store this information. Pherhaps, another option would have been to create a new column in the users table to store this secundary key (key used when accessed by LTI). In this case, the plugin should create the column in the table in its inicialization. The problem then, would be to decide which information from LTI is used to store in the Name field since username is not currently passed in the Moodle LTI consumer.
I have choosen the current option because permitted to pass, as well, the LTI certification tests.