GeoStyler is about styling maps. Maybe you are a developer looking for a set of UI components to build custom and flexible styling widgets for your geospatial application. Maybe you are a cartographer trying to get the style you worked so hard on in your favorite (Q)GIS into the web. Or maybe you are a project lead worrying about migrating all your styles to that new fancy rendering engine everyone (and in particular your boss) is talking about. The GeoStyler ecosystem is here to help.

React Library

One key project of the ecosystem is the React Library providing developers with widgets and tools to build powerful and flexible UIs to style geodata over the web. To get an idea of its features and capabilities you can have a look at the Demo Application or dive into the Source Code. If you want to learn how to build your own custom map styling applications be sure to look into the tutorials and the documentation.

Style Parsers and Transformations

GeoStyler supports multiple style formats used in the open source geospatial ecosystem: QML from QGIS, Mapbox JSON used in MapLibre, OpenLayers Styling Format and the OGC-standardized SLD format used by Geoserver. Each of those can be transformed into one of the others. Each style parser is provided as seperate Github repository and NPM package. You can get an overview of the available style parsers and links here. Be aware that not every styling capability of a particular style is supported. Luckily, GeoStyler is open source and it is easy to contribute and get involved in the community. Styles can either be transformed using JavaScript in your application or with the GeoStyler command-line interface (CLI).

Batch Conversion with the GeoStyler CLI

The GeoStyler command-line interface let’s you convert single style files or entire directories from one of the supported formats into another. Assuming you have node installed on your system, installation is as easy as typing npm install -g geostyler-cli. Once you have the CLI installed you can transform a style, e.g. from QGIS QML format to SLD directly from the command-line:

geostyler -s qgis -t sld -o output.sld input.qml

Make sure to have a look at the repository for further instructions and examples.

Conversion over the Web

Maybe a conversion over the web via HTTP requests is the way to go for your setup and workflow. If so, make sure to have a look at the GeoStyler REST API. Using GET and POST requests you can transform your style over the web. The REST API is built on top of the popular Node.js framework express. Check out the documentation and the repository. Similar to the example above, the following cURL call will transform a simple Mapbox (JSON-Format) style to SLD (XML):

curl -X 'POST' \
  'https://services.meggsimum.de/geostyler-rest/api/rpc/transform?sourceFormat=Mapbox&targetFormat=SLD' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "version": 8,
  "name": "Demo Style",
  "layers": [
    {
      "id": "Rule 1",
      "type": "circle",
      "paint": {
        "circle-radius": 16,
        "circle-color": "#4b33c8"
      }
    }
  ]
}'

Invitation

We hope that GeoStyler can help you building open geospatial tools and maps. If it does, we invite you to get involved: Whether you are a developer providing bug fixes and features, or a user improving the documentation or writing tutorials. We wish you happy and stylish mapping.