Es2015 Custom Element

<!--
  说明：自定义地图元素的中文示例，数据在页面内生成，可独立运行。
  核心逻辑：customElements.define + connectedCallback 创建 Map + disconnectedCallback 释放
  依赖：OpenLayers 10.3.1 · jsDelivr CDN
-->
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta name="robots" content="noindex,follow">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>自定义地图元素</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ol@10.3.1/ol.css">
<style>
  html,body{height:100%;margin:0}
  body{display:flex;flex-direction:column;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif}
  .bar{flex:0 0 auto;padding:8px 12px;background:#f6f7f9;border-bottom:1px solid #e3e6ea;
       display:flex;gap:10px;align-items:center;flex-wrap:wrap;font-size:12px;color:#58606e}
  .bar label{display:flex;gap:5px;align-items:center;cursor:pointer}
  .bar button{font:inherit;padding:3px 9px;border:1px solid #c9ced6;background:#fff;
       border-radius:5px;cursor:pointer;color:#333}
  .bar button:hover{background:#eef2f8}
  .bar input[type=range]{width:110px;vertical-align:middle}
  .bar input[type=text]{font:inherit;padding:2px 6px;border:1px solid #c9ced6;border-radius:4px}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3;position:relative}
  .panel{flex:0 0 auto;max-height:34%;overflow:auto;padding:8px 12px;font-size:12px;
       background:#fff;border-top:1px solid #e3e6ea;color:#3d4451}
  .panel pre{margin:0;font-family:Consolas,"Courier New",monospace;font-size:11px;
       white-space:pre-wrap;word-break:break-all;line-height:1.5}
  .ol-attribution{font-size:11px}
  ol-map-view{display:block;flex:1 1 auto;min-height:0;position:relative;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
<span>地图由 &lt;ol-map-view&gt; 元素提供</span>
<span id="info">—</span>
</div>
<ol-map-view id="map"></ol-map-view>

<script src="https://cdn.jsdelivr.net/npm/ol@10.3.1/dist/ol.js"></script>
<script>
(function () {
  'use strict';

  if (typeof ol === 'undefined') {
    var errBox = document.getElementById('map');
    if (errBox) {
      errBox.innerHTML = '<div style="padding:20px;color:#b42318">OpenLayers 加载失败，请检查能否访问 cdn.jsdelivr.net</div>';
    }
    return;
  }

  var fromLonLat = ol.proj.fromLonLat;
  var info = document.getElementById('info');

  class OlMapView extends HTMLElement {
    constructor() {
      super();
      this._map = null;
    }

    connectedCallback() {
      if (this._map) { return; }
      var host = document.createElement('div');
      host.style.cssText = 'position:absolute;inset:0';
      this.appendChild(host);

      var features = [
        [116.4074, 39.9042, '北京'],
        [121.4737, 31.2304, '上海'],
        [113.2644, 23.1291, '广州']
      ].map(function (p) {
        return new ol.Feature({
          geometry: new ol.geom.Point(fromLonLat([p[0], p[1]])),
          name: p[2]
        });
      });

      this._map = new ol.Map({
        target: host,
        layers: [
          new ol.layer.Tile({source: new ol.source.XYZ({url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}', attributions: 'Tiles © Esri'})}),
          new ol.layer.Vector({
            source: new ol.source.Vector({features: features}),
            style: function (f) {
              return new ol.style.Style({
                image: new ol.style.Circle({
                  radius: 6,
                  fill: new ol.style.Fill({color: '#1f5fd0'}),
                  stroke: new ol.style.Stroke({color: '#ffffff', width: 2})
                }),
                text: new ol.style.Text({
                  text: f.get('name'),
                  offsetY: -15,
                  font: '500 12px sans-serif',
                  fill: new ol.style.Fill({color: '#16181d'}),
                  stroke: new ol.style.Stroke({color: '#ffffff', width: 3})
                })
              });
            }
          })
        ],
        view: new ol.View({center: fromLonLat([112.5, 32.5]), zoom: 4.5}),
        controls: ol.control.defaults.defaults({attribution: false, zoom: true, rotate: false})
      });

      info.textContent = '元素已挂载 · 地图实例在 connectedCallback 中创建';
    }

    disconnectedCallback() {
      if (this._map) {
        this._map.setTarget(null);
        this._map = null;
        info.textContent = '元素已卸载 · 地图实例被释放';
      }
    }
  }

  customElements.define('ol-map-view', OlMapView);
})();
</script>
</body>
</html>