node-mapnik

Bindings to Mapnik for node.



Usage

Render a map from a stylesheet:

``js
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:

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

Convert a shapefile to GeoJSON:

`js
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:

`yaml
language: cpp

sudo: false

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

Installing

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
`

$3

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