Modify feature events

by Vladimir Vershinin

HTML

<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">
  <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-source-osm>
    </vl-layer-tile>
    
    
    <vl-layer-vector id="polygons">
      <vl-source-vector ref="polygonsSource"  :features="polygons"></vl-source-vector>
    </vl-layer-vector>
    
    <vl-interaction-select ident="modify-target"></vl-interaction-select>
    
    <vl-interaction-modify source="modify-target" @modifystart="onModifyStart" @modifyend="onModifyEnd"></vl-interaction-modify>
  </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],
      polygons: [
      	{
        	type: 'Feature',
          id: 'one',
          properties: {},
          geometry: {
          	type: 'Polygon',
            coordinates: [[
            	[0, 0],
              [0, 20],
              [20, 20],
              [20, 0],
              [0, 0],
            ]],
          },
        },
        {
        	type: 'Feature',
          id: 'two',
          properties: {},
          geometry: {
          	type: 'Polygon',
            coordinates: [[
            	[-20, -20],
              [-10, -20],
              [-10, -10],
              [-20, -20],
            ]],
          },
        },
      ],
      modifyingFeatures: {},
      modifiedFeatures: [],
    }
  },
  methods: {
  	onModifyStart (evt) {
    	this.modifyingFeatures = {}
      this.modifiedFeatures = []
    	evt.features.forEach(feature => {
      	this.modifyingFeatures[feature.getId()] = feature.getRevision()
      })
    	console.log('start modify', this.modifyingFeatures)
    },
    onModifyEnd (evt) {
    	this.modifiedFeatures = evt.features.getArray().reduce((modified, feature) => {
      	if (this.modifyingFeatures[feature.getId()] !== feature.getRevision()) {
        	modified.push(feature.getId())
        }
        return modified
      }, [])
    	console.log('end modify', this.modifiedFeatures)
    },
  },
})