We have created abstract class \core\event\content_viewed which would be extended by various modules and triggered to record a content viewed action.

The content that is viewed is identified by the field $other['content'] in the event.

Issues:-

1. Just having an identifier doesn't really describe in detail the content that was viewed.
2. There is no guidelines for what value should be used for identifiers.

Suggestion:-

1. content_viewed classes should define a constant for each of different content which uses this event.
2. Identifier should not have spaces and have all letters in lower case. Underscores can be allowed.
3. $event->get_description() should pass on a more appropriate description based on $other['content'] identifier.