JSFiddle - React, Tailwind, and code Playground

by Ömür Bilgili

HTML

<link rel="stylesheet" href="https://openlayers.org/en/v4.6.5/css/ol.css">
<script src="https://openlayers.org/en/v4.6.5/build/ol.js"></script>
<div id="map">

</div>
<div id="map-scale-bar" data-reactid=".0.2.0">
<div class="ol-scale-line ol-unselectable" style="display: none;">
<div class="ol-scale-line-inner">
</div></div></div>

JavaScript

var map = new ol.Map({
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    })
  ],
  target: 'map',
  view: new ol.View({
    center: [0, 0],
    zoom: 2
  })
});

var scaleLine = new ol.control.ScaleLine({
        target: document.getElementById('map-scale-bar'),
          units: "metric",
          minWidth: 100
      });
      map.addControl(scaleLine);