// A test of maplibre-gl in a custom element class MapLibreTest extends HTMLElement { constructor() { super(); // Create a shadow DOM this.attachShadow({ mode: "open" }); // Initial render this.render(); this._map = null; // markers shown on the map this._markers = []; } // Lifecycle: when element is added to the DOM connectedCallback() { // Initialize the map when the element is added to the DOM setTimeout(() => this._initializeMap(), 0); } disconnectedCallback() { if (this._map) { this._map.remove(); } } // Lifecycle: watch these attributes for changes static get observedAttributes() { return ["latitude", "longitude", "zoom"]; } // Lifecycle: respond to attribute changes attributeChangedCallback(name, oldValue, newValue) { // Only handle if map exists and values actually changed if (!this._map || oldValue === newValue) return; if (name === "latitude" || name === "longitude") { if (this.hasAttribute("latitude") && this.hasAttribute("longitude")) { const lat = Number(this.getAttribute("latitude")); const lng = Number(this.getAttribute("longitude")); this._map.setCenter([lat, lng]); } } if (name === "zoom") { this._map.setZoom(Number(newValue)); } } _initializeMap() { const apiKey = this.getAttribute("api-key"); const lat = Number(this.getAttribute("latitude") || 36.2); const lng = Number(this.getAttribute("longitude") || -119.2); const mapElement = this.shadowRoot.querySelector("#map"); const tegola = this.getAttribute("tegola"); const zoom = Number(this.getAttribute("zoom") || 15); this._map = new maplibregl.Map({ container: mapElement, center: { lat: lat, lng: lng, }, style: "https://tiles.stadiamaps.com/styles/alidade_smooth.json", // Style URL; see our documentation for more options zoom: zoom, }); this._map.on("load", () => { this.dispatchEvent(new CustomEvent("load"), { bubbles: true, composed: true, // Allows event to cross shadow DOM boundary detail: { map: this, }, }); }); } // Initial render of component render() { this.shadowRoot.innerHTML = `