As we are going to add a search tab in T185927, we want to make some changes to eventlogging SearchFunnel on iOS app to figure out the usage of it. Specifically, we'd like to:
- Add a `invoke_Rename the schema to `MobileWikiAppiOSSearch`. After discussing with @mpopov, we agree that it would be less confusing and easier to maintain when iOS and Android using different schemas.
- Add a `source` field to identify the source from which the search interface was invoked: the top of feed, the search tab, or from the article view
- Add a `langswitch` action when users tap on a different language on the search interface
- Add a `position` field to log the position of the search result that was clicked, from the list that was presented to the user
- Add `is_anon`, `primary_language`, `session_id` fields to standardize it with other iOS eventlogging schemas
- Rename field `appInstallID` to `app_install_id`, `ts` to `event_dt`other fields from camelCase to snake_case because our database are case insensitive
- We'd like to send an `results` action not only when new search results are retrieved by API, to standardize it with other iOS eventlogging schemasbut also when cached results are shown.
Schema: https://meta.wikimedia.org/w/index.php?title=iki/Schema:MobileWikiAppiOSSearch&oldid=18126493
Revision number: 1812649332115
We'd also like to add a `search_tab` field to [MobileWikiAppiOSUserHistory](https://meta.wikimedia.org/wiki/Schema:MobileWikiAppiOSUserHistory) to log whether the app opens to the new search tab.
**This task depends on T185927. If there is any design change in T185927, the spec may need to be changed accordingly.**