A Flutter plugin that provides a webview widget is available now for Developers Preview. Here is an example:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 | // Copyright 2018 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // ignore_for_file: public_member_api_docs import 'dart:async'; import 'dart:convert'; import 'package:flutter/material.dart'; import 'package:webview_flutter/webview_flutter.dart'; void main() => runApp(MaterialApp(home: WebViewExample())); const String kNavigationExamplePage = ''' <!DOCTYPE html><html> <head><title>Navigation Delegate Example</title></head> <body> <p> The navigation delegate is set to block navigation to the youtube website. </p> <ul> <ul><a href="https://www.youtube.com/">https://www.youtube.com/</a></ul> <ul><a href="https://www.google.com/">https://www.google.com/</a></ul> </ul> </body> </html> '''; class WebViewExample extends StatefulWidget { @override _WebViewExampleState createState() => _WebViewExampleState(); } class _WebViewExampleState extends State<WebViewExample> { final Completer<WebViewController> _controller = Completer<WebViewController>(); @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: const Text('Flutter WebView example'), // This drop down menu demonstrates that Flutter widgets can be shown over the web view. actions: <Widget>[ NavigationControls(_controller.future), SampleMenu(_controller.future), ], ), // We're using a Builder here so we have a context that is below the Scaffold // to allow calling Scaffold.of(context) so we can show a snackbar. body: Builder(builder: (BuildContext context) { return WebView( initialUrl: 'https://flutter.dev', javascriptMode: JavascriptMode.unrestricted, onWebViewCreated: (WebViewController webViewController) { _controller.complete(webViewController); }, // TODO(iskakaushik): Remove this when collection literals makes it to stable. // ignore: prefer_collection_literals javascriptChannels: <JavascriptChannel>[ _toasterJavascriptChannel(context), ].toSet(), navigationDelegate: (NavigationRequest request) { if (request.url.startsWith('https://www.youtube.com/')) { print('blocking navigation to $request}'); return NavigationDecision.prevent; } print('allowing navigation to $request'); return NavigationDecision.navigate; }, onPageStarted: (String url) { print('Page started loading: $url'); }, onPageFinished: (String url) { print('Page finished loading: $url'); }, gestureNavigationEnabled: true, ); }), floatingActionButton: favoriteButton(), ); } JavascriptChannel _toasterJavascriptChannel(BuildContext context) { return JavascriptChannel( name: 'Toaster', onMessageReceived: (JavascriptMessage message) { Scaffold.of(context).showSnackBar( SnackBar(content: Text(message.message)), ); }); } Widget favoriteButton() { return FutureBuilder<WebViewController>( future: _controller.future, builder: (BuildContext context, AsyncSnapshot<WebViewController> controller) { if (controller.hasData) { return FloatingActionButton( onPressed: () async { final String url = await controller.data.currentUrl(); Scaffold.of(context).showSnackBar( SnackBar(content: Text('Favorited $url')), ); }, child: const Icon(Icons.favorite), ); } return Container(); }); } } enum MenuOptions { showUserAgent, listCookies, clearCookies, addToCache, listCache, clearCache, navigationDelegate, } class SampleMenu extends StatelessWidget { SampleMenu(this.controller); final Future<WebViewController> controller; final CookieManager cookieManager = CookieManager(); @override Widget build(BuildContext context) { return FutureBuilder<WebViewController>( future: controller, builder: (BuildContext context, AsyncSnapshot<WebViewController> controller) { return PopupMenuButton<MenuOptions>( onSelected: (MenuOptions value) { switch (value) { case MenuOptions.showUserAgent: _onShowUserAgent(controller.data, context); break; case MenuOptions.listCookies: _onListCookies(controller.data, context); break; case MenuOptions.clearCookies: _onClearCookies(context); break; case MenuOptions.addToCache: _onAddToCache(controller.data, context); break; case MenuOptions.listCache: _onListCache(controller.data, context); break; case MenuOptions.clearCache: _onClearCache(controller.data, context); break; case MenuOptions.navigationDelegate: _onNavigationDelegateExample(controller.data, context); break; } }, itemBuilder: (BuildContext context) => <PopupMenuItem<MenuOptions>>[ PopupMenuItem<MenuOptions>( value: MenuOptions.showUserAgent, child: const Text('Show user agent'), enabled: controller.hasData, ), const PopupMenuItem<MenuOptions>( value: MenuOptions.listCookies, child: Text('List cookies'), ), const PopupMenuItem<MenuOptions>( value: MenuOptions.clearCookies, child: Text('Clear cookies'), ), const PopupMenuItem<MenuOptions>( value: MenuOptions.addToCache, child: Text('Add to cache'), ), const PopupMenuItem<MenuOptions>( value: MenuOptions.listCache, child: Text('List cache'), ), const PopupMenuItem<MenuOptions>( value: MenuOptions.clearCache, child: Text('Clear cache'), ), const PopupMenuItem<MenuOptions>( value: MenuOptions.navigationDelegate, child: Text('Navigation Delegate example'), ), ], ); }, ); } void _onShowUserAgent( WebViewController controller, BuildContext context) async { // Send a message with the user agent string to the Toaster JavaScript channel we registered // with the WebView. await controller.evaluateJavascript( 'Toaster.postMessage("User Agent: " + navigator.userAgent);'); } void _onListCookies( WebViewController controller, BuildContext context) async { final String cookies = await controller.evaluateJavascript('document.cookie'); Scaffold.of(context).showSnackBar(SnackBar( content: Column( mainAxisAlignment: MainAxisAlignment.end, mainAxisSize: MainAxisSize.min, children: <Widget>[ const Text('Cookies:'), _getCookieList(cookies), ], ), )); } void _onAddToCache(WebViewController controller, BuildContext context) async { await controller.evaluateJavascript( 'caches.open("test_caches_entry"); localStorage["test_localStorage"] = "dummy_entry";'); Scaffold.of(context).showSnackBar(const SnackBar( content: Text('Added a test entry to cache.'), )); } void _onListCache(WebViewController controller, BuildContext context) async { await controller.evaluateJavascript('caches.keys()' '.then((cacheKeys) => JSON.stringify({"cacheKeys" : cacheKeys, "localStorage" : localStorage}))' '.then((caches) => Toaster.postMessage(caches))'); } void _onClearCache(WebViewController controller, BuildContext context) async { await controller.clearCache(); Scaffold.of(context).showSnackBar(const SnackBar( content: Text("Cache cleared."), )); } void _onClearCookies(BuildContext context) async { final bool hadCookies = await cookieManager.clearCookies(); String message = 'There were cookies. Now, they are gone!'; if (!hadCookies) { message = 'There are no cookies.'; } Scaffold.of(context).showSnackBar(SnackBar( content: Text(message), )); } void _onNavigationDelegateExample( WebViewController controller, BuildContext context) async { final String contentBase64 = base64Encode(const Utf8Encoder().convert(kNavigationExamplePage)); await controller.loadUrl('data:text/html;base64,$contentBase64'); } Widget _getCookieList(String cookies) { if (cookies == null || cookies == '""') { return Container(); } final List<String> cookieList = cookies.split(';'); final Iterable<Text> cookieWidgets = cookieList.map((String cookie) => Text(cookie)); return Column( mainAxisAlignment: MainAxisAlignment.end, mainAxisSize: MainAxisSize.min, children: cookieWidgets.toList(), ); } } class NavigationControls extends StatelessWidget { const NavigationControls(this._webViewControllerFuture) : assert(_webViewControllerFuture != null); final Future<WebViewController> _webViewControllerFuture; @override Widget build(BuildContext context) { return FutureBuilder<WebViewController>( future: _webViewControllerFuture, builder: (BuildContext context, AsyncSnapshot<WebViewController> snapshot) { final bool webViewReady = snapshot.connectionState == ConnectionState.done; final WebViewController controller = snapshot.data; return Row( children: <Widget>[ IconButton( icon: const Icon(Icons.arrow_back_ios), onPressed: !webViewReady ? null : () async { if (await controller.canGoBack()) { await controller.goBack(); } else { Scaffold.of(context).showSnackBar( const SnackBar(content: Text("No back history item")), ); return; } }, ), IconButton( icon: const Icon(Icons.arrow_forward_ios), onPressed: !webViewReady ? null : () async { if (await controller.canGoForward()) { await controller.goForward(); } else { Scaffold.of(context).showSnackBar( const SnackBar( content: Text("No forward history item")), ); return; } }, ), IconButton( icon: const Icon(Icons.replay), onPressed: !webViewReady ? null : () { controller.reload(); }, ), ], ); }, ); } } |
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