Feature style

by Vladimir Vershinin

HTML

<script src="https://unpkg.com/[email protected]/dist/vue.js"></script>
<script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/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">
<script src="https://cdn.jsdelivr.net/npm/[email protected]/lodash.min.js"></script>
<div id="app">
  <div>
    <span v-if="message">
      {{ message }}
    </span>
    <div v-if="features.length > 0">
      <label v-for="feature in features" :key="feature.id">
        <input type="checkbox" v-model="feature.properties.active">
        Feature {{ feature.id }}
      </label>
    </div>
  </div>

  <vl-map ref="map" data-projection="EPSG:4326">
    <vl-view ref="mapView" :zoom.sync="zoom" :center.sync="center"></vl-view>

    <vl-layer-tile id="osm">
      <vl-source-osm></vl-source-osm>
    </vl-layer-tile>

    <vl-layer-vector>
      <vl-source-vector ref="geojsonSource" url="https://gist.githubusercontent.com/ghettovoice/37ef37dd571ed39b0985c16560b157d3/raw/3499326b779d6c2c2e28ec49c9e492be3bbf8f0f/map.geojson" :features.sync="features"></vl-source-vector>
      <vl-style-func :factory="styleFuncFactory"></vl-style-func>
    </vl-layer-vector>
  </vl-map>
</div>

CSS

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

.layers {
  position: absolute;
  top: 10px;
  left: 50px;
  z-index: 1;
}

JavaScript

new Vue({
  el: '#app',
  data() {
    return {
      zoom: 2,
      center: [0, 0],
      sourceFeatures: [],
      message: 'Loading...',
    }
  },
  computed: {
  	features: {
    	get () {
      	return this.sourceFeatures
      },
      set (features) {
      	this.sourceFeatures = features.map(f => JSON.parse(JSON.stringify(f)))
      },
    },
  },
  watch: {
    features: _.debounce(function() {
      this.message = `Loaded ${this.features.length}`

      this.$refs.mapView.$view.fit(
        this.$refs.geojsonSource.$source.getExtent(), {
          duration: 1000,
        },
      )
    }, 100),
  },
  methods: {
    styleFuncFactory() {
      const defaultFill = new ol.style.Fill({
        color: [255, 255, 255, 0.5]
      })
      const defaultStroke = new ol.style.Stroke({
        color: 'blue',
        width: 1.25,
      })
      const defaultStyle = new ol.style.Style({
        fill: defaultFill,
        stroke: defaultStroke,
        image: new ol.style.Circle({
        	radius: 5,
          fill: defaultFill,
          stroke: defaultStroke,
        }),
      })

      const activeStroke = new ol.style.Stroke({
        color: 'green',
        width: 2
      })
      const activestyle = new ol.style.Style({
        fill: defaultFill,
        stroke: activeStroke,
        image: new ol.style.Circle({
        	radius: 10,
          fill: defaultFill,
          stroke: activeStroke,
        }),
      })

      return feature => {
        if (feature.get('active')) {
          return activestyle
        }
        return defaultStyle
      }
    }
  },
})