mapnik

node-mapnik

Bindings to Mapnik for node.

Usage

Render a map from a stylesheet:

var mapnik = require('mapnik');
var fs = require('fs');

// register fonts and datasource plugins
mapnik.register_default_fonts();
mapnik.register_default_input_plugins();

var map = new mapnik.Map(256, 256);
map.load('./test/stylesheet.xml', function(err,map) {
    if (err) throw err;
    map.zoomAll();
    var im = new mapnik.Image(256, 256);
    map.render(im, function(err,im) {
      if (err) throw err;
      im.encode('png', function(err,buffer) {
          if (err) throw err;
          fs.writeFile('map.png',buffer, function(err) {
              if (err) throw err;
              console.log('saved map image to map.png');
          });
      });
    });
});

Convert a jpeg image to a png:

var mapnik = require('mapnik');
new mapnik.Image.open('input.jpg').save('output.png');

Convert a shapefile to GeoJSON:

var mapnik = require('mapnik');
mapnik.register_datasource(path.join(mapnik.settings.paths.input_plugins,'shape.input'));
var ds = new mapnik.Datasource({type:'shape',file:'test/data/world_merc.shp'});
var featureset = ds.featureset()
var geojson = {
  "type": "FeatureCollection",
  "features": [
  ]
}
var feat = featureset.next();
while (feat) {
    geojson.features.push(JSON.parse(feat.toJSON()));
    feat = featureset.next();
}
fs.writeFileSync("output.geojson",JSON.stringify(geojson,null,2));

For more sample code see the tests and sample code.

Requirements

Starting from v4.5.0, node-mapnik module is published as "universal" binaries using node-addon-api All Node.js versions >= 10 are known to work, consult N-API documentation for more details: https://nodejs.org/dist/latest/docs/api/n-api.html#n_api_node_api_version_matrix

An installation error like below indicates your system does not have a modern enough libstdc++/gcc-base toolchain:

Error: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version GLIBCXX_3.4.21 not found (required by /node_modules/mapnik/lib/binding/mapnik.node)

If you are running Ubuntu older than 16.04 you can easily upgrade your libstdc++ version like:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update -y
sudo apt-get install -y libstdc++-6-dev

To upgrade libstdc++ on travis (without sudo) you can do:

language: cpp

sudo: false

addons:
  apt:
    sources:
     - ubuntu-toolchain-r-test
    packages:
     - libstdc++-6-dev # upgrade libstdc++

Installing

With npm

Just do:

npm install mapnik

Note: This will install the latest node-mapnik 4.5.x series, which is recommended.

Source Build

There are two ways to build from source. These work on both OS X and Linux:

• A) Against a binary package from Mapnik from mason
• B) Against an existing version of Mapnik on your system

Using A) is recommended. You do not need to have Mapnik installed already, so this is the easiest and most predictable approach. When you use the route a binary package of Mapnik is downloaded dynamically from mason.

You can invoke this method simply by running:

make release

Or, for debug builds:

make debug

If you want to do a full rebuild do:

make distclean

And then re-run the build:

make release

Using B) is also possible, if you would like to build node-mapnik against an external, already installed Mapnik version.

In this case you need to have a Mapnik version installed that is at least as recent as the mapnik_version property in the package.json for the branch of node-mapnik you want to build.

And you need to have the mapnik-config program is available and on your ${PATH}.

Then run (within the cloned node-mapnik directory:

make release_base

or

make debug_base

for release and debug builds, respectively.

Note on SSE:

By default node mapnik is built with SSE support. If you are building on a platform that is not x86_64 you will need to disable feature by setting the environment variable SSE_MATH=false.

SSE_MATH=false make

Building against Mapnik 3.0.x

The master branch of node-mapnik is not compatible with 3.0.x series of Mapnik. To build against Mapnik 3.0.x, use v3.0.x branch.

Using node-mapnik from your node app

To require node-mapnik as a dependency of another package put in your package.json:

"dependencies"  : { "mapnik":"*" } // replace * with a given semver version string

Tests

To run the tests do:

npm test

License

BSD, see LICENSE.txt

Changelog

4.5.9

• Image - fix object lifetimes/scopes in relevant async methods (#978)
• Add persistent Buffer reference to Image to ensure underlying buffer stays in scope (in situations when Image doesn't own underlyling data)
• Image - update ctor and remove ad-hoc _buffer field
• Use Napi::EscapableHandleScope in Image::buffer and Image::data