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tilelive-mapnik-cartodb

tilelive-mapnik

Renderer backend for tilelive.js that uses node-mapnik to render tiles and grids from a Mapnik XML file. tilelive-mapnik implements the Tilesource API.

Installation

npm install tilelive-mapnik

Though tilelive is not a dependency of tilelive-mapnik you will want to install it to actually make use of tilelive-mapnik through a reasonable API.

Usage

var tilelive = require('tilelive');
require('tilelive-mapnik').registerProtocols(tilelive);
 
tilelive.load('mapnik:///path/to/file.xml', function(err, source) {
    if (err) throw err;
 
    // Interface is in XYZ/Google coordinates. 
    // Use `y = (1 << z) - 1 - y` to flip TMS coordinates. 
    source.getTile(0, 0, 0, function(err, tile, headers) {
        // `err` is an error object when generation failed, otherwise null. 
        // `tile` contains the compressed image file as a Buffer 
        // `headers` is a hash with HTTP headers for the image. 
    });
 
    // The `.getGrid` is implemented accordingly. 
});

Note that grid generation will only work when there's a .mml file with the same basename as the XML file in that directory that contains information about how interactivity should be rendered.

Alternatively you may pass data to tilelive-mapnik directly using an XML string and MML object.

var uri = {
    protocol: 'mapnik:',
    slashes: true,
    xml: '<?xml version="1.0" encoding="utf-8"?>\n<Map srs="+proj=merc ... ',
    mml: {
        interactivity: {
            layer: 'world',
            fields: ['NAME']
        },
        format: 'png'
    }
};
tilelive.load(uri, function(err, source) {
    // ... 
});