Offline Mode

Overview

Displays a cached page when there is no network connection, and lets you control offline mode from JavaScript. Android and iOS use the same JS API.

Feature	Android	iOS
Read offline state	✓	✓
Control offline mode	✓	✓
Cache control	✓	✓

Supported Plan: Basic and above

Reading Offline State

Read whether offline mode is currently active with cache.getOfflineMode(), synchronously.

const isOffline = window.unveilyBridge.cache.getOfflineMode();  // boolean

if (isOffline) {
  showOfflineBanner();
}

The same value is also included as the isOffline field in the app.getInfo response.

window.unveilyBridge.app.getInfo("onAppInfo");

function onAppInfo(info) {
  console.log(info.isOffline);  // boolean
}

Offline state is polled

The SDK does not fire a global event for network changes. Query the state directly with getOfflineMode() or getInfo() whenever you need it (e.g. on screen entry, or when a request fails).

setOfflineMode

Explicitly enable or disable offline mode. The first argument is a boolean; you may optionally pass the name of a result callback (a string) as the second argument.

// Turn offline mode on
window.unveilyBridge.cache.setOfflineMode(true);

// Pass a callback name to receive the result
window.unveilyBridge.cache.setOfflineMode(true, "onOfflineModeResult");

function onOfflineModeResult(result) {
  console.log(result.enabled);  // boolean — the applied state
  console.log(result.success);  // boolean — whether it succeeded
  // On failure, result.error contains the reason
}

If you omit the callback name, the default onOfflineModeResult is used.

Offline Fallback Page Setup

Configure the page to show when there is no network in assets/config.json.

assets/config.json

{
  "offline": {
    "enabled": true,
    "fallbackPage": "offline.html"
  }
}

Create app/src/main/assets/offline.html. Since the SDK does not fire network-change events, use a retry button to reload the page.

app/src/main/assets/offline.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Offline</title>
</head>
<body>
  <h1>Please check your internet connection</h1>
  <p>Once your network is restored, press the button below to try again.</p>
  <button type="button" onclick="window.location.reload()">Try again</button>
</body>
</html>

Cache Control

clearCache

Clears the WebView cache. Use this when you need to force a refresh after an app update. The argument is a boolean; passing true reloads the page after clearing the cache.

window.unveilyBridge.cache.clearCache(true);   // clear then reload
window.unveilyBridge.cache.clearCache(false);  // clear only