Points styling

by Vladimir Vershinin

HTML

<script src="https://unpkg.com/[email protected]/lodash.js"></script>
<script src="https://unpkg.com/vue@latest/dist/vue.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io/en/v5.3.0/build/ol.js"></script>
<script src="https://npmcdn.com/@turf/turf/turf.min.js"></script>
<script src="https://unpkg.com/[email protected]/lib/index.umd.js"></script>
<link rel="stylesheet" href="https://unpkg.com/[email protected]/lib/style.css">
<div id="app">
  <div>Current zoom {{ zoom }}</div>
  <vl-map ref="map" data-projection="EPSG:4326">
    <vl-view ref="mapView" :zoom.sync="zoom" :center.sync="center"></vl-view>
    
    <vl-layer-tile>
      <vl-source-osm />
    </vl-layer-tile>
    
    <vl-layer-vector id="points" render-mode="image">
      <vl-source-vector :features="points" />
      <vl-style-func :factory="pointsStyleFunc" />
    </vl-layer-vector>
    
  </vl-map>  
</div>

CSS

html, body, #app {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}

JavaScript

new Vue({
	el: '#app',
  data () {
  	return {
    	zoom: 2,
      center: [0, 0],
      points: _.range(0, 100).map(i => {
      	let coordinate = [
        	_.random(-50, 50),
          _.random(-50, 50),
        ]
        return {
          type: 'Feature',
          id: 'point-' + i,
          geometry: {
            type: 'Point',
            coordinates: coordinate,
          },
          properties: {
	          number: i + 1,
          	address: '1234567, Russia, Moscow, ...',
          },
        }
      }),
    }
  },
  methods: {
    pointsStyleFunc () {
      // style function and styles using OpenLayers API
      // https://openlayers.org/en/latest/apidoc/module-ol_style_Style.html
      return feature => {
        let baseStyle = new ol.style.Style({
          image: new ol.style.Circle({
            radius: 10,
            fill: new ol.style.Fill({
            	color: '#fff',
            }),
            stroke: new ol.style.Stroke({
              color: '#F44336',
            }),
          }),
          text: new ol.style.Text({
          	text: String(feature.get('number')), // get feature property
          }),
        })
      	return [
        	baseStyle,
        ]
      }
    },
  },
})