cordova-plugin-android-cookieflush

A Cordova plugin that forces the Android WebView's CookieManager to flush cookies to disk immediately, so cookies (e.g. login/session cookies) are not lost when the app process is killed shortly after they are set or cleared.

Platform: Android only Minimum SDK: Android 5.0 (API 21) npm: https://www.npmjs.com/package/cordova-plugin-android-cookieflush

Why

Android's WebView (Chromium) batches cookie writes and only persists them to disk periodically (roughly every 30 seconds). If the app process is killed before that flush happens — for example when the user exits via the hardware back button, or the OS reclaims the process — any cookie written or deleted in that window is lost. On the next launch the WebView reads the stale cookie jar from disk, so a fresh login can appear logged out, or a logout can appear still logged in.

android.webkit.CookieManager.flush() forces the in-memory cookie jar to be written to disk. This plugin exposes that call to JavaScript and also runs it automatically when the app is paused or destroyed.

Installation

cordova plugin add cordova-plugin-android-cookieflush

What it does

Provides one method on cordova.plugins.cookieFlush:

| Method | Description | |--------|-------------| | flush(success, error) | Forces the WebView cookie jar to be written to disk. Both callbacks are optional. |

In addition, the plugin flushes automatically (no JS required) on the Android lifecycle events onPause and onDestroy, covering Home-button, task-switch, and swipe-away closes.

Usage

Call flush right before exiting the app, or after a login/logout, so the cookie change reaches disk before the process can be killed:

cordova.plugins.cookieFlush.flush(
    function () {
        // cookies persisted — safe to exit
        navigator.app.exitApp();
    },
    function (err) {
        console.error('Cookie flush failed:', err);
        navigator.app.exitApp();
    }
);

flush is safe to call fire-and-forget (both callbacks are optional):

cordova.plugins.cookieFlush.flush();

Notes

• Android only. iOS WKWebView has no equivalent flush API; cookies there are persisted by WKWebsiteDataStore automatically. The plugin is not installed on other platforms, so a guarded call is a safe no-op.
• The flush() JS call runs CookieManager.flush() on a background thread; the automatic onPause/onDestroy flushes run synchronously so they complete before the process is torn down.

License

ISC