Offline map

[wipfli]

What is the best way to use PMTiles for an offline map?

Ideally, I would like to have a single html file with all the javascript embedded and maybe the pmtiles file could be base64 encoded and stored as a string in javascript or so. Do you think that is possible?

[bdon]

Run a local HTTP server.

The other option is to use the file:// protocol, but this requires user interaction to access the filesystem for security reasons.

The base64 idea could also work but seems like it would be pretty ugly after a few megabytes. You'd have to write a new class implementing the Source interface that is backed by a simple ArrayBuffer loaded from the base64 string.

[wipfli]

Somehow it would be really cool if we could do stuff like this:

"sources": {
  "mytiles": {
    "type": "vector",
    "url": "pmtiles://data:application/octet-stream;base64,UE1UaWxl..."
  }
}

[wipfli]

I mean you are right @bdon that this becomes ugly past a few megabytes, but I would find it fun...

[wipfli]

Here is a demo: https://wipfli.github.io/swiss-map/base64/#18/43.733407/7.419744

[bdon]

@wipfli awesome!

I think it's really cool but adding another code path for base64-encoded PMTiles means another thing to maintain for a niche use case. If your data is small enough to fit inline in the web page I think non-tiled GeoJSON is always a better choice for that. I'm having a hard time thinking of practical examples where this would be a superior choice.

[wipfli]

You are right, GeoJSON seems better for offline maps. Thanks for the hint...