preview view model

src/Link.js

@@ -24,7 +24,7 @@ const EVENT_WITH_ROOMALIAS_PATTERN = /^[#]([^:]*):(.+)\/\$([^:]+):(.+)$/;
 const USERID_PATTERN = /^@([^:]+):(.+)$/;
 const GROUPID_PATTERN = /^\+([^:]+):(.+)$/;
 
-export const IdentifierKind = createEnum(
+const IdentifierKind = createEnum(
 	"RoomId",
 	"RoomAlias",
 	"UserId",
@@ -60,6 +60,9 @@ function orderedUnique(array) {
 
 export class Link {
 	static parseFragment(fragment) {
+		if (!fragment) {
+			return null;
+		}
 		let [identifier, queryParams] = fragment.split("?");
 
 		let viaServers = [];
@@ -117,7 +120,7 @@ export class Link {
 			const localPart = matches[1];
 			return new Link(viaServers, IdentifierKind.GroupId, localPart, server);
 		}
-		return;
+		return null;
 	}
 
 	constructor(viaServers, identifierKind, localPart, server, messageLocalPart = null, messageServer = null) {

src/RootViewModel.js

@@ -0,0 +1,36 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {Link} from "./Link.js";
+import {ViewModel} from "./ViewModel.js";
+import {PreviewViewModel} from "./preview/PreviewViewModel.js";
+
+export class RootViewModel extends ViewModel {
+	constructor(request, hash) {
+		super();
+		this._request = request;
+		this.link = Link.parseFragment(hash);
+		this.previewViewModel = null;
+	}
+
+	load() {
+		if (this.link) {
+			this.previewViewModel = new PreviewViewModel(this._request, this.link);
+			this.emitChange();
+			this.previewViewModel.load();
+		}
+	}
+}

src/main.js

@@ -1,16 +1,10 @@
 import {xhrRequest} from "./utils/xhr.js";
-import {validateHomeServer} from "./matrix/HomeServer.js";
-import {Link, LinkKind} from "./Link.js";
+import {RootViewModel} from "./RootViewModel.js";
 
-export async function main() {
-	const link = Link.parseFragment(location.hash);
-	if (!link) {
-		throw new Error("bad link");
-	}
-	const hs = await validateHomeServer(xhrRequest, link.servers[0]);
-	if (link.kind === LinkKind.User) {
-		const profile = await hs.getUserProfile(link.identifier);
-		const imageURL = hs.mxcUrlThumbnail(profile.avatar_url, 64, 64, "crop");
-		console.log(imageURL);
-	}
+export async function main(container) {
+	const vm = new RootViewModel(xhrRequest, location.hash);
+	vm.load();
+	window.__rootvm = vm;
+	// const view = new RootView(vm);
+	// container.appendChild(view.mount());
 }

src/preview/HomeServer.js

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-export async function validateHomeServer(request, baseURL) {
+export async function resolveServer(request, baseURL) {
 	if (!baseURL.startsWith("http://") && !baseURL.startsWith("https://")) {
 		baseURL = `https://${baseURL}`;
 	}

src/preview/PreviewViewModel.js

@@ -0,0 +1,58 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {LinkKind} from "../Link.js";
+import {ViewModel} from "../ViewModel.js";
+import {resolveServer} from "./HomeServer.js";
+
+export class PreviewViewModel extends ViewModel {
+	constructor(request, link) {
+		super();
+		this._link = link;
+		this._request = request;
+		this.loading = false;
+		this.name = null;
+		this.avatarURL = null;
+	}
+
+	async load() {
+		this.loading = true;
+		this.emitChange();
+		for (const server of this._link.servers) {
+			try {
+				const homeserver = await resolveServer(this._request, server);
+				switch (this._link.kind) {
+					case LinkKind.User:
+						await this._loadUserPreview(homeserver, this._link.identifier);
+				}
+				// assume we're done if nothing threw
+				break;
+			} catch (err) {
+				continue;
+			}
+		}
+		this.loading = false;
+		this.emitChange();
+	}
+
+	async _loadUserPreview(homeserver, userId) {
+		const profile = await homeserver.getUserProfile(userId);
+		this.name = profile.displayname || userId;
+		this.avatarURL = profile.avatar_url ?
+			homeserver.mxcUrlThumbnail(profile.avatar_url, 64, 64, "crop") :
+			null;
+	}
+}