✨ Registration URL Hint - Show contextual hint and live URL preview for event registration link

[ssw-yakshaver]

Requested by: @PennyWalker via YakShaver.ai 🦬
cc: @0xharkirat, @PennyWalker, @wicksipedia, @adamcogan, @brookjeynes-ssw, @babakamyljanovssw

Hi Team!

  🟥  Watch the video (2 min 14 sec)

  Url from screen share: https://ssw.com.au/admin/index.html#/collections/edit/eventsCalendar/2026/May-User-Group---Talk-TBA

Pain

On the Tina Events page in the ⭐ SSW Website (Dev - Next.js), content editors are confused about what value to enter into the new Registration Link field. Add a contextual hint below the text field that explains the expected input with a simple example, and dynamically renders the resulting event URL. When the field is empty, the hint should show the default generated URL; as the user types, the hint should update in real time to reflect the overridden URL.

Acceptance Criteria

1. A hint is displayed underneath the Registration Link text field on the Tina Events page.
2. The hint is visible on initial page load before any input is entered.
3. When the Registration Link field is empty, the hint shows the default generated event URL.
4. As the user types into the Registration Link field, the hint dynamically updates to display the resulting URL.
5. The hint includes a simple example (e.g. "Sydney-May") to guide users on the expected format.
6. The hint text clearly indicates that only a short, simple value is required (not a full URL).
7. The change does not affect existing events that already have a registration link configured.

Screenshot

Figure: Missing example hint for event registration link input