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