Mapml vector tiles - ready to roll

[aaime]

Pull request rebased on the latest main branch. Now can skip attributes on tiled features and can cache tiles in "text/mapml" format. Documentation updated. @prushforth do you see anything else that needs to be done?

Checklist

• [ ] I have read the contribution guidelines.
• [ ] I have sent a Contribution Licence Agreement (not required for small changes, e.g., fixing typos in documentation).
• [ ] First PR targets the main branch (backports managed later; ignore for branch specific issues).
• [ ] All the build checks are green (see automated QA checks).

For core and extension modules:

• [ ] New unit tests have been added covering the changes.
• [ ] Documentation has been updated (if change is visible to end users).
• [ ] The REST API docs have been updated (when changing configuration objects or the REST controllers).
• [ ] There is an issue in the GeoServer Jira (except for changes that do not affect administrators or end users in any way).
• [ ] Commit message(s) must be in the form [GEOS-XYZWV] Title of the Jira ticket.
• [ ] Bug fixes and small new features are presented as a single commit.
• [ ] Each commit has a single objective (if there are multiple commits, each has a separate JIRA ticket describing its goal).

[prushforth]

Wow pretty impressive! Just itching to see this combined with styles. I saw this at first then realized it was user error:

Should I be able to use this request when the thing is set up to cache text/mapml tiles and expect it to filter the states?

http://localhost:8080/geoserver/topp/wms?service=WMS&version=1.1.0&request=GetMap&layers=topp%3Astates&bbox=-1.3885038382960921E7%2C2870337.130793682%2C-7455049.489182421%2C6338174.0557576185&width=768&height=414&srs=MapML%3AOSMTILE&styles=&format=text%2Fhtml%3B%20subtype%3Dmapml&cql_filter=PERSONS%3E5000000

[prushforth]

do you see anything else that needs to be done?

Forgetting about the MapML:projection value across restarts is still an issue.

Apart from that: good to go!

[prushforth]

Actually I'm seeing a bunch of html responses to what should be a text/mapml tile request:

Layer is set to cache tiles in text/mapml format, "Use Tiles" and "Use Features". All requests there are made by the viewer, i.e. each is a tile request, but what gets returned is sometimes the "front" text/html document as shown.

[prushforth]

Actually I'm seeing a bunch of html responses to what should be a text/mapml tile request:

This ~might be~ is a bug in the viewer.

[aaime]

Wow pretty impressive! Just itching to see this combined with styles. I saw this at first then realized it was user error:

Should I be able to use this request when the thing is set up to cache text/mapml tiles and expect it to filter the states?

http://localhost:8080/geoserver/topp/wms?service=WMS&version=1.1.0&request=GetMap&layers=topp%3Astates&bbox=-1.3885038382960921E7%2C2870337.130793682%2C-7455049.489182421%2C6338174.0557576185&width=768&height=414&srs=MapML%3AOSMTILE&styles=&format=text%2Fhtml%3B%20subtype%3Dmapml&cql_filter=PERSONS%3E5000000

No, you should not expect that, at least by default, because each possible CQL_FILTER value would have to generate a separate on disk cache (filter changes the content of the tiles). If that's your intent, then go and add a "filter parameter" in the tile layer configuraton for CQL_FILTER, with a regex to catch the valid values (or .* for a quick test). I don't remember if the cql_filter gets replicated on WMTS links or not, that needs to be verified.

[aaime]

Actually I'm seeing a bunch of html responses to what should be a text/mapml tile request:

This ~might be~ is a bug in the viewer.

I don't see it happening anymore with client version 0.13 though (I cherry-picked it temporarily to test it out)

[aaime]

PR updated, CQL support for cached tiles as well (as long as the filter parameter is defined), and also, geometric simplification based on the current output resolution, to reduce the size of mapml tiles. This should be it for this PR.

I'll look at the CRS issue on restart in a different PR.

[prushforth]

I'll look at the CRS issue on restart in a different PR.

Thanks!

[aaime]

I'll look at the CRS issue on restart in a different PR.

Thanks!

See https://github.com/geoserver/geoserver/pull/7486

Here is an example of setting topp:states in MapML:CBMTILE that works (for me at least) after applying the above changes:

[prushforth]

I can't run the change (at work today) right now. If it works for you, that's enough for me for now; please merge as you see fit.