Offline vector maps in Cordova using Mapbox GL JS

A mapbox-gl-js build capable of reading local mbtiles in cordova. Tested on Android, and (to a lesser extent) on iOS.

Run example application

npm install
cordova platform add android
cordova run android

The Android emulator browser won't display WebGL content, please run on a physical Android device

npm install
cordova platform add ios
cordova run ios

Will use www/data/2017-07-03_spain_barcelona.mbtiles as sample data source, and www/styles/osm-bright/style-offline.json as style, both coming from the OpenMapTiles project: https://openmaptiles.org/

Integrate in your application

Use the bundled library from www/mapbox-gl-cordova-offline.js which is based in mapbox-gl-js v.0.53.1, or install it as npm dependency (npm install oscarfonts/mapbox-gl-cordova-offline).

Add the following cordova plugins via "cordova plugin add" command:

* "cordova-plugin-device"
* "cordova-plugin-file"
* "cordova-sqlite-ext"

Use the OfflineMap constructor. It returns a promise instead of a map, as the offline map creation process is asynchronous:

       new mapboxgl.OfflineMap({
            container: 'map',
            style: 'styles/osm-bright/style-offline.json'
       }).then(function(map) {
           map.addControl(new mapboxgl.NavigationControl());
       });

See www/index.html in this repo for a working example.

Offline data sources (mbtiles)

In your style, you can specify offline tile sources specifying mbtiles as the source type, and the location to the mbtiles file as a relative path:

"sources": {
    "openmaptiles": {
        "type": "mbtiles",
        "path": "data/2017-07-03_spain_barcelona.mbtiles"
    }
}

Additional styles can be found in OpenMapTiles repos (see gh-pages branches): https://github.com/openmaptiles Vector tiles for other regions can be downloaded here: https://openmaptiles.com/downloads/planet/

Raster tiles

You can add raster tiles in offline mode. In the style you have to add a new source with type rasteroffline with the relative path:

"sources": {
    "hillshading": {
        "type": "rasteroffline",
        "path": "data/2016-11-28-hillshade-spain_barcelona.mbtiles"
    }
}

The style related to this source will be the same that a common Mapbox raster layer. You have to relate the layer with the source using the source name, and the type of the layer have to be raster as a common raster Mapbox layer.

{
      "id": "hillshading",
      "type": "raster",
      "source": "hillshading",
      "layout": {
        "visibility": "visible"
      },
      "paint": {
        "raster-opacity": {
          "base": 0.5,
          "stops": [
            [
              3,
              0
            ],
            [
              5,
              0.5
            ],
            [
              12,
              0.5
            ]
          ]
        },
        "raster-fade-duration": 300,
        "raster-contrast": 0
      }
    }

Offline sprites (icon set)

Copy the files sprite.json, sprite.png, sprite@2x.json and sprite@2x.png as local resources and reference them as a relative path in your style:

"sprite": "styles/osm-bright/sprite"

Offline glyphs (fonts)

Search "text-font" attributes in your style. Download the needed fonts from https://github.com/openmaptiles/fonts (see gh-pages branch) and copy them locally. Set the relative path in the "glyphs" property of the style:

"glyphs": "fonts/{fontstack}/{range}.pbf"

Enable live reload for development

1. Get the your development computer's IP address (ifconfig).
2. Edit www/index.html and put your IP address in the script tag that loads the mapbox-gl-cordova-offline.js resource: <script src='http://xxx.xxx.xxx.xxx:8080/www/mapbox-gl-cordova-offline.js'></script>. For live reload to work, change also the IP_ADDRESS_AND_PORT var, and uncomment the code block at the end of the document.
3. Run npm start.

Every time the contents in src/ are changed, the file www/mapbox-gl-cordova-offline.js will be rebuilt, and the web view will be reloaded.