1 files changed, 109 insertions, 0 deletions
diff --git a/shared/utils/src/launch/launch-client.ts b/shared/utils/src/launch/launch-client.ts
new file mode 100644
index 0000000..24378d6
--- /dev/null
+++ b/shared/utils/src/launch/launch-client.ts
@@ -0,0 +1,109 @@
+import { createClientLink } from './scheme';
+import type { Platform } from '../platform';
+
+/**
+ * Navigator for older Microsoft (MS) browsers like Internet Explorer.
+ */
+type MSNavigator = Navigator & {
+    msLaunchUri: (
+        href: string | URL,
+        successCallback: () => void,
+        failureCallback: () => void,
+    ) => void;
+};
+
+/**
+ * Check if the given value is an MSNavigator.
+ */
+function isMSNavigator(value: Partial<MSNavigator>): value is MSNavigator {
+    return typeof value?.msLaunchUri === 'function';
+}
+
+/**
+ * Callback for client launches.
+ */
+export type LaunchCallback = (result: {
+    link: URL;
+    success: boolean;
+}) => void | Promise<void>;
+
+/**
+ * Attempt to launch the native client for the given Web URL.
+ */
+export function launchClient(
+    url: string | URL,
+    platform: Platform,
+    callback: LaunchCallback = () => {},
+): void {
+    const { window, browser, os } = platform;
+
+    /** URL for opening the native application */
+    const link = createClientLink(url, { platform });
+
+    // macOS Safari
+    if (os.isMacOS && browser.isSafari) {
+        launchOnMacOS(link, platform, callback);
+    }
+    // Proprietary msLaunchUri method (IE 10+ on Windows 8+)
+    else if (isMSNavigator(platform.navigator)) {
+        platform.navigator.msLaunchUri(
+            String(link),
+            () => callback({ link, success: true }),
+            () => callback({ link, success: false }),
+        );
+    }
+    // Other platforms
+    else {
+        try {
+            // on iOS, Windows and Android simply opening the href works
+            window!.top!.window.location.href = String(link);
+            callback({ link, success: true });
+        } catch (e) {
+            // we know this is NOT installed
+            callback({ link, success: false });
+        }
+    }
+}
+
+function launchOnMacOS(
+    link: URL,
+    platform: Platform,
+    callback: LaunchCallback,
+): void {
+    const { window } = platform;
+
+    if (typeof window === 'undefined') {
+        callback({ link, success: false });
+        return;
+    }
+
+    /** Timer for blur fallback */
+    let timer: number;
+
+    /** IFrame reference for opening the client link */
+    let iframe: HTMLIFrameElement | undefined;
+
+    /** Cleanup function run after the client launch has been initiated */
+    function finalize() {
+        clearTimeout(timer);
+        window!.removeEventListener('blur', finalize);
+        if (iframe !== undefined) {
+            window!.document.body.removeChild(iframe);
+        }
+
+        callback({ link, success: true });
+    }
+
+    // Add an iFrame window to the current document to open the URL
+    iframe = window.document.createElement('iframe');
+    iframe.id = 'launch-client-opener';
+    iframe.style.display = 'none';
+    window.document.body.appendChild(iframe);
+
+    // Redirect the iFrame to the client link to trigger it to open
+    iframe.contentWindow!.location.href = String(link);
+
+    // Wait a tiny amount of time for the client launch to appear
+    window.addEventListener('blur', finalize);
+    timer = setTimeout(finalize, 50) as unknown as number;
+}