Process Global Config

Process Global Configuration for Android-specific WebView. WebView has some process-global configuration parameters that cannot be changed once WebView has been loaded. This class allows apps to set these parameters.

If it is used, the configuration should be set and apply should be called prior to loading WebView into the calling process. Most of the methods in android.webkit and androidx.webkit packages load WebView, so the configuration should be applied before calling any of these methods.

Basic Usage

apply can only be called once. Trying to call it more than once, will result in a PlatformException.

Only a single thread should access this class at a given time.

The configuration should be set up as early as possible during application startup, to ensure that it happens before any other thread can call a method that loads WebView.

The following code configures the data and cache directory base path and the data directory suffix that WebView uses and then applies the configuration. WebView uses this configuration when it is loaded.

Before applying the configuration, you should check if the related Android WebView startup feature is currently supported or not.

In this example, I'm also using the path_provider plugin to get the Application Documents Directory as the directory base path.

Example:

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';
import 'package:path_provider/path_provider.dart';

Future main() async {
  WidgetsFlutterBinding.ensureInitialized();

  final dataDirectorySuffix = (await WebViewFeature.isStartupFeatureSupported(
          WebViewFeature.STARTUP_FEATURE_SET_DATA_DIRECTORY_SUFFIX))
      ? 'suffix_inappwebviewexample'
      : null;

  final appDocsPath = (await getApplicationDocumentsDirectory()).absolute.path;

  final directoryBasePaths = (await WebViewFeature.isStartupFeatureSupported(
          WebViewFeature.STARTUP_FEATURE_SET_DIRECTORY_BASE_PATHS))
      ? ProcessGlobalConfigDirectoryBasePaths(
          cacheDirectoryBasePath: '$appDocsPath/inappwebviewexample/cache',
          dataDirectoryBasePath: '$appDocsPath/inappwebviewexample/data')
      : null;

  try {
    // call apply before any API related to Android WebViews
    await ProcessGlobalConfig.instance().apply(
        settings: ProcessGlobalConfigSettings(
            dataDirectorySuffix: dataDirectorySuffix,
            directoryBasePaths: directoryBasePaths));
  } catch (e) {
    // use try/catch if you are calling more than once
    // for example, when hot restarting your Flutter App.
    print(e);
  }

  if (!kIsWeb && defaultTargetPlatform == TargetPlatform.android) {
    // for example, this API is related to Android WebViews.
    // if you call this method before ProcessGlobalConfig.apply,
    // the apply method won't work
    await InAppWebViewController.setWebContentsDebuggingEnabled(kDebugMode);
  }

  runApp(const MaterialApp(home: MyApp()));
}