Add WMTS Time Dimension Support (Discrete Times + Timeline)

[ShubhamSharmaFAO]

Add WMTS Time Dimension Support (Discrete Times + Timeline)

As part of the WMTS implementation supporting FAO infrastructure, I would like to contribute WMTS Time Dimension Support. Please review the following proposal:

Summary

Bring upstream WMTS to parity on time handling, matching the current branch:

• Parse WMTS Dimension for time, including lists and ISO ranges (start/end/period).
• Expand ranges to discrete instants (honoring maxRefreshIntervals), expose them to the timeline/animation stack.
• Select a default time (capabilities Default if present, otherwise latest discrete time).
• Pass the chosen time into WMTS requests (including REST ResourceURL templates).

Acceptance criteria

• WMTS layer with a time dimension shows a Terria timeline; stepping/animating updates time in requests.
• ISO time ranges in capabilities are expanded into discrete instants (bounded by maxRefreshIntervals).
• Default time comes from the capabilities Default value when present; otherwise the most recent discrete time is used.
• REST ResourceURL templates receive the selected time value (single timestamp).

Testing

• Unit/integration:
  • ISO range expansion to discrete times (start/end/interval) with maxRefreshIntervals cap.
  • Default time selection logic (capabilities Default vs latest).
  • Request construction: time propagated into REST template URLs and WMTS parameters.
• Manual:
  • Use a WMTS layer with time ranges; verify timeline appears, stepping updates time, and tiles load.
  • Verify a range like 2018-01-01/2020-01-01/P1M expands and animates; check that the latest date is chosen when no default is specified.

[ShubhamSharmaFAO]

@na9da Just checking in to see if this works for your team.
When you have time, it would be great to start this thread.
Once this is complete, I can open a proposal for non–time-based dimensions and legends.

[zoran995]

Hi @ShubhamSharmaFAO the proposal looks solid to me. Few notes from my side

• I assume you plan to follow the WMS approach for handling the time dimensions, and create imagery provider per time?
• Non-time dimensions (elevation) should probably a follow-up?

• Select a default time (capabilities Default if present, otherwise latest discrete time).

In WMS we use initialTimeSource should we also use the same here?