Select delayed features

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://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>
    {{ featuresState }}
  </div>
  <vl-map ref="map" data-projection="EPSG:4326">
    <vl-view ref="view"
             :zoom.sync="zoom" 
             :center.sync="center"></vl-view>
    <vl-layer-tile>
      <vl-source-osm></vl-source-osm>
    </vl-layer-tile>
    
    <vl-layer-vector>
      <vl-source-vector :features="features"></vl-source-vector>
      <vl-style-box>
        <vl-style-icon src="https://img.icons8.com/office/50/000000/place-marker.png" :anchor="[0.5, 1]"></vl-style-icon>
      </vl-style-box>
    </vl-layer-vector>
    
    <vl-interaction-select :condition="selectCondition">
      <vl-style-box>
        <vl-style-icon src="https://img.icons8.com/ultraviolet/50/000000/place-marker.png" :anchor="[0.5, 1]"></vl-style-icon>
      </vl-style-box>
    </vl-interaction-select>
  </vl-map>  
</div>

CSS

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

#app {
  display: flex;
  flex-direction: column;
}

.vl-map {
  overflow: hidden;
}

JavaScript

new Vue({
	el: '#app',
  data () {
  	return {
    	zoom: 2,
      center: [0, 0],
      features: [],
    }
  },
  computed: {
  	layerFeatureIds () {
    	return this.features.map(f => f.id)
    },
    featuresState () {
    	if (this.features.length) {
      	return 'Loaded: ' + this.layerFeatureIds.length
      }
      
      return 'Loading....'
    },
  },
  mounted () {
  	this.loadFeatures().then(features => console.log('loaded', features))
  },
  methods: {
	  selectCondition: ol.events.condition.click,
  	loadFeatures () {
    	return new Promise(resolve => {
      	setTimeout(() => {
        	this.features = _.range(0, 100).map(i => ({
          	type: 'Feature',
            id: 'point-' + (i + 1),
            properties: {},
            geometry: {
            	type: 'Point',
              coordinates: [
              	_.random(-50, 50),
                _.random(-50, 50),
              ],
            },
          }))
          
          resolve(this.features)
        }, 3000)
      })
    },
  }
})