Custom chart elements

Plugins can embed custom elements that personalize charts: color palettes and map backgrounds. In order to add a custom element, you must add the element description in a Javascript file in the plugin content.

Color palettes

See Color palettes for general information about color palettes in charts.

Color palettes can provide same graph color patterns across different charts. From the global Javascript object dkuColorPalettes, there are three different functions depending on the palette type:

  • Discrete: dkuColorPalettes.addDiscrete(palette)
  • Continuous: dkuColorPalettes.addContinuous(palette)
  • Diverging (continous but colors expand to both side from the middle value): dkuColorPalettes.addDiverging(palette)

The palette object has several properties:

  • id: unique ID across all color palettes in DSS
  • name: displayed name
  • category: category in the list
  • colors: array of the ordered colors (can be #012345 or rgb(r, g, b) styles)
  • values: array of the ordered values (a value can be null for auto matching)
dkuColorPalettes.addDiscrete({
        id: 'palette-id',
        name: 'palette-name',
        category: 'palette-category',
        colors: ['#012345', 'rbg(r, g, b)'],
        values: [1, 2]
});

Map backgrounds

Map backgrounds can be customized in order to improve map style or to enable maps on offline DSS instances. From the global Javascript object dkuMapBackgrounds, there are three different function to add a map background:

  • dkuMapBackgrounds.addMapbox(mapId, displayLabel, accessToken): add a Mapbox background, see Mapbox documentation Note that a “Mapbox” plugin for DSS already allows you to add Mapbox backgrounds.

    • mapId Mapbox identifier of the background
    • displayLabel How it will appear in DSS
    • accessToken Mapbox API token
dkuMapBackgrounds.addMapbox('mapbox.satellite', 'Satellites', 'ABCDE1234');
  • dkuMapBackgrounds.addWMS(id, name, category, wmsURL, layerId): add a generic WMS layer, see Leaflet documentation

    • id unique ID across all map backgrounds in DSS
    • name displayed name
    • category category in the list
    • wmsURL WMS service URL
    • layerId layer ID of the WMS service
dkuMapBackgrounds.addWMS('mws-map-bg', 'Map background', 'My backgrounds', 'http://mesonet.agron.iastate.edu/cgi-bin/wms/nexrad/n0r.cgi', 'nexrad-n0r-900913');
  • dkuMapBackgrounds.addCustom(background): a custom map background

    • id unique ID across all map backgrounds in DSS
    • name displayed name
    • category category in the list
    • fadeColor color of faded map object
    • getTileLayer function that returns a Leaflet TileLayer object, see Leaflet documentation
dkuMapBackgrounds.addCustom({
        id: 'map-bg',
        name: 'Map background 2',
        category: 'Custom map backgrounds',
        fadeColor: '#333',
        getTileLayer: function() {
                return new L.tileLayer('http://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png', {
                        attribution: '&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, &copy; <a href="http://cartodb.com/attributions">CartoDB</a>'
                });
        }
});