Add CesiumIonAuthPlugin (#638)

* Add ion auth plugin

* Add Cesium ion auth plugin

* Provide option for url or passing into the cesium ion plugin

* Updates

src/base/TilesRendererBase.js

@@ -78,7 +78,7 @@ export class TilesRendererBase {
 
 	}
 
-	constructor( url ) {
+	constructor( url = null ) {
 
 		// state
 		this.tileSets = {};
@@ -167,7 +167,7 @@ export class TilesRendererBase {
 		const rootTileSet = tileSets[ this.rootURL ];
 		if ( ! ( this.rootURL in tileSets ) ) {
 
-			this.loadRootTileSet( this.rootURL );
+			this.invokeOnePlugin( plugin => plugin.loadRootTileSet && plugin.loadRootTileSet( this.rootURL ) );
 			return;
 
 		} else if ( ! rootTileSet || ! rootTileSet.root ) {

src/three/plugins/CesiumIonAuthPlugin.js

@@ -0,0 +1,99 @@
+const UNLOADED = 0;
+const LOADING = 1;
+const LOADED = 2;
+const FAILED = 3;
+
+export class CesiumIonAuthPlugin {
+
+	constructor( { apiToken, assetId = null } ) {
+
+		this.name = 'CESIUM_ION_AUTH_PLUGIN';
+		this.apiToken = apiToken;
+		this.assetId = assetId;
+		this.tiles = null;
+		this._tileSetVersion = - 1;
+		this._tokenState = UNLOADED;
+		this._loadPromise = null;
+
+	}
+
+	init( tiles ) {
+
+		this.tiles = tiles;
+
+	}
+
+	loadRootTileSet( rootUrl ) {
+
+		if ( this._tokenState === UNLOADED ) {
+
+			this._tokenState = LOADING;
+
+			// construct the url to fetch the endpoint
+			let url;
+			if ( this.assetId === null ) {
+
+				url = new URL( rootUrl );
+
+			} else {
+
+				url = new URL( `https://api.cesium.com/v1/assets/${ this.assetId }/endpoint` );
+
+			}
+
+			url.searchParams.append( 'access_token', this.apiToken );
+
+			// load the ion asset information
+			this._loadPromise = fetch( url, { mode: 'cors' } )
+				.then( res => {
+
+					if ( res.ok ) {
+
+						return res.json();
+
+					} else {
+
+						return Promise.reject( new Error( `${ res.status } : ${ res.statusText }` ) );
+
+					}
+
+				} ).then( json => {
+
+					this._tokenState = LOADED;
+
+					// retrieve the url version
+					const tiles = this.tiles;
+					const url = new URL( json.url );
+					this._tileSetVersion = url.searchParams.get( 'v' );
+					tiles.rootURL = url;
+					tiles.fetchOptions.headers = tiles.fetchOptions.headers || {};
+					tiles.fetchOptions.headers.Authorization = `Bearer ${ json.accessToken }`;
+
+					return tiles.loadRootTileSet( tiles.rootURL );
+
+				} ).catch( err => {
+
+					this._tokenState = FAILED;
+					return Promise.reject( err );
+
+				} );
+
+		}
+
+		return this._loadPromise;
+
+	}
+
+	preprocessURL( uri ) {
+
+		uri = new URL( uri );
+		if ( /^http/.test( uri.protocol ) && this._tileSetVersion != - 1 ) {
+
+			uri.searchParams.append( 'v', this._tileSetVersion );
+
+		}
+		return uri.toString();
+
+	}
+
+}

src/three/renderers/CesiumIonTilesRenderer.js

@@ -1,79 +1,14 @@
 import { TilesRenderer } from '../TilesRenderer.js';
 import { DebugTilesRenderer } from '../DebugTilesRenderer.js';
+import { CesiumIonAuthPlugin } from '../plugins/CesiumIonAuthPlugin.js';
 
-const UNLOADED = 0;
-const LOADING = 1;
-const LOADED = 2;
-const FAILED = 3;
 const CesiumIonTilesRendererMixin = base => class extends base {
 
 	constructor( ionAssetId, ionAccessToken ) {
 
 		super();
-		this._tokenState = UNLOADED;
-		this._ionAccessToken = ionAccessToken;
-		this._ionAssetId = ionAssetId;
-		this._tileSetVersion = - 1;
-		this.preprocessURL = uri => {
 
-			uri = new URL( uri );
-			if ( /^http/.test( uri.protocol ) && this._tileSetVersion != - 1 ) {
-
-				uri.searchParams.append( 'v', this._tileSetVersion );
-
-			}
-			return uri.toString();
-
-		};
-
-	}
-
-	update() {
-
-		const state = this._tokenState;
-		if ( state === UNLOADED ) {
-
-			this._tokenState = LOADING;
-
-			const url = new URL( `https://api.cesium.com/v1/assets/${ this._ionAssetId }/endpoint` );
-			url.searchParams.append( 'access_token', this._ionAccessToken );
-
-			fetch( url, { mode: 'cors' } ).then( res => {
-
-				if ( res.ok ) {
-
-					return res.json();
-
-				} else {
-
-					return Promise.reject( `${ res.status } : ${ res.statusText }` );
-
-				}
-
-			} ).then( json => {
-
-				this._tokenState = LOADED;
-
-				// retrieve the url version
-				const url = new URL( json.url );
-				this._tileSetVersion = url.searchParams.get( 'v' );
-				this.rootURL = url;
-				this.fetchOptions.headers = this.fetchOptions.headers || {};
-				this.fetchOptions.headers.Authorization = `Bearer ${ json.accessToken }`;
-				// Actually load the tileset now that we got its url from the cesium ion server
-				super.update();
-
-			} ).catch( () => {
-
-				this._tokenState = FAILED;
-
-			} );
-
-		} else if ( state === LOADED ) {
-
-			super.update();
-
-		}
+		this.registerPlugin( new CesiumIonAuthPlugin( { apiToken: ionAccessToken, assetId: ionAssetId } ) );
 
 	}