JarCastingmbtiles
Node.js utilities and tilelive integration for the MBTiles format.
Installation
npm install @mapbox/mbtiles
var MBTiles = require('@mapbox/mbtiles');
API
Constructor
All MBTiles instances need to be constructed before any of the methods become available. NOTE: All methods described below assume you've taken this step.
new MBTiles('./path/to/file.mbtiles?mode={ro, rw, rwc}', function(err, mbtiles) {
console.log(mbtiles) // mbtiles object with methods listed below
});
The mode query parameter is a opening flag of mbtiles. It is optional, default as rwc. Available flags are:
ro: readonly mode, will throw error if the mbtiles does not exist.rw: read and write mode, will throw error if the mbtiles does not exist.rwc: read, write and create mode, will create a new mbtiles if the mbtiles does not exist.
Reading
getTile(z, x, y, callback)
Get an individual tile from the MBTiles table. This can be a raster or gzipped vector tile. Also returns headers that are important for serving over HTTP.
mbtiles.getTile(z, x, y, function(err, data, headers) {
// `data` is your gzipped buffer - use zlib to gunzip or inflate
});
getInfo(callback)
Get info of an MBTiles file, which is stored in the metadata table. Includes information like zoom levels, bounds, vector_layers, that were created during generation. This performs fallback queries if certain keys like bounds, minzoom, or maxzoom have not been provided.
mbtiles.getInfo(function(err, info) {
console.log(info); // info
});
getGrid(z, x, y, callback)
Get a UTFGrid tile from the MBTiles table.
mbtiles.getGrid(z, x, y, function(err, data) {
// continue onwards
});
Writing
startWriting AND stopWriting
In order to write a new (or currently existing) MBTiles file you need to "start" and "stop" writing. First, construct the MBTiles object.
mbtiles.startWriting(function(err) {
// start writing with mbtiles methods (putTile, putInfo, etc)
mbtiles.stopWriting(function(err) {
// stop writing to your mbtiles object
});
});
putTile(z, x, y, buffer, callback)
Add a new tile buffer to a specific ZXY. This can be a raster tile or a gzipped vector tile (we suggest using require('zlib') to gzip your tiles).
var zlib = require('zlib');
zlib.gzip(fs.readFileSync('./path/to/file.mvt'), function(err, buffer) {
mbtiles.putTile(0, 0, 0, buffer, function(err) {
// continue onward
});
});
putInfo(data, callback)
Put an information object into the metadata table. Any nested JSON will be stringified and stored in the "json" row of the metadata table. This will replace any matching key/value fields in the table.
var exampleInfo = {
"name": "hello-world",
"description":"the world in vector tiles",
"format":"pbf",
"version": 2,
"minzoom": 0,
"maxzoom": 4,
"center": "0,0,1",
"bounds": "-180.000000,-85.051129,180.000000,85.051129",
"type": "overlay",
"json": `{"vector_layers": [ { "id": "${layername}", "description": "", "minzoom": 0, "maxzoom": 4, "fields": {} } ] }`
};
mbtiles.putInfo(exampleInfo, function(err) {
// continue onward
});
putGrid(z, x, y, grid, callback)
Inserts a UTFGrid tile into the MBTiles store. Grids are in JSON format.
var fs = require('fs');
var grid = JSON.parse(fs.readFileSync('./path/to/grid.json', 'utf8'));
mbtiles.putGrid(0, 0, 0, grid, function(err) {
// continue onward
});
Hook up to tilelive
When working at scale, node-mbtiles is meant to be used within a Tilelive ecosystem. For example, you could set up an MBTiles file as a "source" and an S3 destination as a "sink" (using tilelive-s3). Assuming you have a system set up with an mbtiles:// protocol that points to a specific file and authorized to write to the s3 bucket:
var tilelive = require('@mapbox/tilelive');
var MBTiles = require('@mapbox/mbtiles');
var s3 = require('@mapbox/tilelive-s3');
s3.registerProtocols(tilelive);
MBTiles.registerProtocols(tilelive);
var sourceUri = 'mbtiles:///User/hello/path/to/file.mbtiles';
var sinkUri = 's3://my-bucket/tiles/{z}/{x}/{y}';
// load the mbtiles source
tilelive.load(sourceUri, function(err, src) {
// load the s3 sink
tilelive.load(sinkUri, function(err, dest) {
var options = {}; // prepare options for tilelive copy
options.listScheme = src.createZXYStream(); // create ZXY stream from mbtiles
// now copy all tiles to the destination
tilelive.copy(src, dst, options, function(err) {
console.log('tiles are now on s3!');
});
});
});
Test
npm test
