mapnik-reference

mapnik-reference is a spec of what Mapnik styling and datasource properties are supported for each version.

It is useful for building parsers, tests, compilers, and syntax highlighting/checking for languages.

Default branch is gh-pages which is displayed at http://mapnik.org/mapnik-reference

Versioning

The version of this repository indicates the schema of the reference.json file. Schema changes of any type are expected to change the implementation requirements of a parser, so they will increment the major version of this repository in semver style.

The directories in this repository directly correspond to released versions of Mapnik and the next targeted release of Mapnik.

Meaning

The structure of the file is as such:

• version: the version of Mapnik targeted. Same as the containing directory.
• style: properties of the Style XML element
• layer: properties of the Layer XML element
• symbolizers/*: properties that apply to all symbolizers
• symbolizers/symbolizer: properties that apply to each type of symbolizer
• colors: named colors supported by Mapnik. see include/mapnik/css_color_grammar.hpp

Property stability

The status key may be used to define the stability of a property. When the key is not specified, then the status is stable. Possible values are:

• stable: property is here to stay and its behavior is not anticipated to change
• unstable: property is here to stay but its behavior/meaning of property may change
• deprecated: property should not be used and will be removed in upcoming major version of Mapnik
• experimental: property should not be used and may change, be re-named, or disappear at any time

Using

This is a valid npm module and therefore can easily be used with node.js.

npm install mapnik-reference

Install it as a dependency of your application. Then use that API to get a reference instance for a specific version of Mapnik:

var mapnik_reference = require('mapnik-reference');
var ref = mapnik_reference.load('3.0.0');

You can also get access to an array of all known versions:

var mapnik_reference = require('mapnik-reference');
mapnik_reference.versions;
[ '2.0.0',
  '2.0.1',
  '2.0.2',
  '2.1.0',
  '2.1.1',
  '2.2.0',
  '2.3.0',
  '3.0.0' ]

Other implementations will want to simply copy the JSON file from the desired implementation, like 2.0.1/reference.json.

The file can then be parsed with any of the many json parsers.

Testing

Tests require python and node.js:

make test

Users

• carto.js
• Mapnik itself (the util/validate-mapnik-instance.py is used to check binding consistency like in #1427)