Write JSON from Lua object.

[BenOnTrack]

Hi Richard,

Is there a way, during the Lua process, to generate out-of-the-box data ?
Today I have a Lua process to generate tiles that contain all relations with the tag route=foot.
I'd like as well to generate another JSON (or anything similar) that would contain the name, id and bbox, directly in the same Lua process (or if necessary, in another run). For instance, once scanned, and used in relation_function, instead of only writing layers, would there be a way as well to write those features in another object that has basically nothing to do with TileMaker ?

If so, is there a way to access the geometry of the object being written ? and then post-process it with turf for instance ?

[systemed]

Sorry, I missed this one initially. No, there isn't at present.

We have a few Lua instances running simultaneously, so I guess building this would require a common in-memory store, Lua wrappers to write to it, and a bunch of GeoJSON serialisation code. Probably quite complex for a fairly niche case.

You could perhaps have a go at writing something in your Lua code that opened a new file on init_function, appended to it as required in way_function/node_function, and closed it in exit_function. At present you'd be limited to writing the object ID and the object centroid - the Lua scripts don't have access to any other part of the geometry. Because there are several Lua instances, you'd probably want to generate a unique filename in init_function for each time it was called.

[BenOnTrack]

Thanks for the tips!