Vector Tile Transformer

Vector Tile Transformer lets you change Vector Tiles in a stream.

API

stream = vtt(function(data, fn){ /* ... */ })

A transform stream passing the unpacked vector tile data to a function for modification.

Example

const fs = require("fs");

const src = fs.createReadStream("tile-in.pbf");
const dest = fs.createWriteStream("tile-out.pbf");

const vtt = require("vtt");

src.pipe(vtt(function(layers, done){

    // filter layers by name
    layers = layers.filter(function(layer){
        return (layer.name !== "keepme");
    });

    // add a property to all features in a layer
    layers[0] = layers[0].map(function(feature){
        feature.properties.modified = true;
        return feature;
    });

    done(null, layers); // err, data

})).pipe(dest);

data

[{
    version: 2,
    name: "name",
    extent: 4096,
    features: [{
        id: 1,
        type: 1,
        properties: {
            key: "value",
        },
        geometry: (...geometry),
    }],
}]

data = vtt.unpack(buffer);

Sync convenience method to turn an uncompressed vector tile into an object

buffer = vtt.pack(data);

Sync convenience method to turn an object back into an uncompressed vector tile

License

UNLICENSE