In T179426: Identify typical time to first user interaction, we used the current Page Previews EventLogging instrumentation to try to determine the typical time to first user link interaction (see T179426#3741809 and T179426#3741859). Unfortunately, the use of the server-side timestamp, which is only accurate to the second, was too high granularity in order to move forward with T179426: Identify typical time to first user interaction.
Per T180036#374696, we'll add a high-precision timestamp to the existing EventLogging instrumentation. So, we'll:
- Add an event_timestamp field to the Popups schema.
- In the client, set the field to performance.now for every event we send.
- The field could/should be added in [the src/reducers/eventLogging.js#createEvent function](https://github.com/wikimedia/mediawiki-extensions-Popups/blob/e1be05d73f308fcdc7723bcd8792b61fd6a69f77/src/reducers/eventLogging.js#L35-L59).
- All events have event_timestamp values added to them (in case of link interaction events, referring to the end of the interaction rather than its start). The timestamps should only be retrieved using performance.now when it's available.
- This is mostly a point of principle: the reducers should only be combining data with existing state.
- Per T180036#3749812, if performance.now is unavailable for some reason, send undefined or null.
- Whenever possible, high-precision timestamps are sent with all Popups events.
- EventLogging for popups is disabled on production so we will need to test this on the beta cluster
- On the beta cluster bucket yourself by passing the debug=true parameter
- Every event should include a timestamp field. To verify this open the developer console and inspect the network tab (you can filter by event). Check all possible event types to see if this is true and the number is always increasing.
- We should check for a variety of browsers that we care about.
Sign off steps
- Given EventLogging is disabled on production (per T178500: Stop sending data for Page Previews enwiki and dewiki A/B test (again)), what is the plan/card to re-enable it to actually collect the information we need...? Please create a card.