Follow TileJSON spec for metadata table

[rubenpoppe]

In #44 a model for the metadata table was added, but vector_layers is part of the json row. Is there a specific reason for this? The 3.0 TileJSON spec defines vector_layers to be a top level field. And in none of the other versions the json field is a thing. The mbtiles tilelive seems to acknowledge this and transforms the data.

[bdon]

vector_layers as part of the json key is part of the MBTiles spec. https://github.com/mapbox/mbtiles-spec/blob/master/1.3/spec.md#vector_layers

Any program that presents TileJSON based on MBTiles needs to transform the metadata table slightly. The data structure for Tippecanoe follows MBTiles because that's what the existing MBTiles and dirtiles expect, and how the test suite is organized. Is there a specific use case where the internal data model needs to be different?

[rubenpoppe]

Oh, I see. I was just wondering why it was that way. Thanks for clearing it up!

[reyemtm]

bringing this back up - the use case is - run tippecanoe, and in the case of output to a directory - create a tilejson which has the tiles end point, bounds, min and max zoom, such that you can add the data to a map using data: "https://.../tilejson.json" instead of manually setting the tiles, bounds, min and max zoom. You might need one additional cli option to set the root url, not sure.