[fuchsia_webview_flutter] Register objects in frame before load
TESTED=current tests continue to pass, verified on webview_example and on device.
Change-Id: I39e8fab1633ce177429f9e6d22182f686afd4cd2
diff --git a/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_web_services.dart b/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_web_services.dart
index 46e10e1..536356c 100644
--- a/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_web_services.dart
+++ b/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_web_services.dart
@@ -3,12 +3,10 @@
// found in the LICENSE file.
import 'dart:async';
-import 'dart:convert' show utf8;
import 'dart:io';
import 'package:fidl/fidl.dart';
import 'package:fidl_fuchsia_io/fidl_async.dart' as fidl_io;
-import 'package:fidl_fuchsia_mem/fidl_async.dart' as fidl_mem;
import 'package:fidl_fuchsia_web/fidl_async.dart' as fidl_web;
import 'package:fuchsia_logger/logger.dart';
import 'package:fuchsia_scenic_flutter/child_view_connection.dart';
@@ -133,15 +131,36 @@
// TODO(crbug.com/900391): Investigate if we can run the scripts in
// isolated JS worlds.
Future<String> evaluateJavascript(List<String> origins, String script) async {
- final vmo = SizedVmo.fromUint8List(utf8.encode(script));
- final buffer = fidl_mem.Buffer(vmo: vmo, size: vmo.size);
+ final buffer = utils.stringToBuffer(script);
// TODO(nkosote): add catchError and decorate the error based on the error
// code.
- // TODO(miguelfrde): replace with executeJavaScript once chromium rolls.
- await frame.executeJavaScriptNoResult(origins, buffer);
- final resultVmo = SizedVmo.fromUint8List(utf8.encode('1'));
- final resultBuffer = fidl_mem.Buffer(vmo: resultVmo, size: resultVmo.size);
- return utils.bufferToString(resultBuffer);
+ final result = await frame.executeJavaScript(origins, buffer);
+ return utils.bufferToString(result);
+ }
+
+ /// Executes a UTF-8 encoded `script` for every subsequent page load where the
+ /// [`fuchsia.web.Frame`]'s URL has an origin reflected in `origins`. The script is executed
+ /// early, prior to the execution of the document's scripts.
+ ///
+ /// Scripts are identified by a client-managed identifier `id`. Any script previously injected
+ /// using the same `id` will be replaced.
+ ///
+ /// The order in which multiple bindings are executed is the same as the order in which the
+ /// bindings were added. If a script is added which clobbers an existing script of the same
+ /// `id`, the previous script's precedence in the injection order will be preserved.
+ ///
+ /// At least one `origins` entry must be specified. If a wildcard `"*"` is specified in
+ /// `origins`, then the script will be evaluated unconditionally.
+ ///
+ /// If an error occured, the [`fuchsia.web.FrameError`] will be set to one of these values:
+ /// - `BUFFER_NOT_UTF8`: `script` is not UTF-8 encoded.
+ /// - `INVALID_ORIGIN`: `origins` is an empty vector.
+ Future<void> evaluateJavascriptBeforeLoad(
+ int id, List<String> origins, String script) async {
+ final buffer = utils.stringToBuffer(script);
+ // TODO(miguelfrde): add catchError and decorate the error based on the error
+ // code.
+ await frame.addBeforeLoadJavaScript(id, origins, buffer);
}
/// Posts a message to the [fidl_web.Frame]'s onMessage handler.
@@ -162,9 +181,9 @@
String message, {
InterfaceRequest<fidl_web.MessagePort> outgoingMessagePortRequest,
}) {
- final vmo = SizedVmo.fromUint8List(utf8.encode(message));
+ final data = utils.stringToBuffer(message);
var msg = fidl_web.WebMessage(
- data: fidl_mem.Buffer(vmo: vmo, size: vmo.size),
+ data: data,
outgoingTransfer: outgoingMessagePortRequest != null
? [
fidl_web.OutgoingTransferable.withMessagePort(
diff --git a/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_webview_platform_controller.dart b/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_webview_platform_controller.dart
index 0f00952..f9a5f69 100644
--- a/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_webview_platform_controller.dart
+++ b/public/dart/fuchsia_webview_flutter/lib/src/fuchsia_webview_platform_controller.dart
@@ -14,19 +14,26 @@
import 'fuchsia_web_services.dart';
import 'utils.dart' as utils;
+class _ChannelSubscription {
+ StreamSubscription<String> subscription;
+ final int id;
+ _ChannelSubscription(this.id, {this.subscription});
+}
+
/// Fuchsia [WebViewPlatformController] implementation that serves as the entry
/// point for all [fuchsia_webview_flutter/webview.dart]'s apis
class FuchsiaWebViewPlatformController extends WebViewPlatformController {
/// Helper class to interact with fuchsia web services
FuchsiaWebServices _fuchsiaWebServices;
String _currentUrl;
- // Reason: sdk_version_set_literal unsupported until version 2.2
+ int _nextId = 0;
+ // Reason: not supported until v2.2 and we need to support earlier
+ // versions.
// ignore: prefer_collection_literals
- final _pendingChannels = Set<String>();
+ var _beforeLoadChannels = Set<String>();
final WebViewPlatformCallbacksHandler _platformCallbacksHandler;
- final _javascriptChannelSubscriptions =
- <String, StreamSubscription<String>>{};
+ final _javascriptChannelSubscriptions = <String, _ChannelSubscription>{};
/// Initializes [FuchsiaWebViewPlatformController]
FuchsiaWebViewPlatformController(this._platformCallbacksHandler,
@@ -36,10 +43,10 @@
fuchsiaWebServices.setNavigationEventListener(
_WebviewNavigationEventListener(_onNavigationStateChanged));
updateSettings(creationParams.webSettings);
+ _addBeforeLoadChannels(creationParams.javascriptChannelNames);
if (creationParams.initialUrl != null) {
loadUrl(creationParams.initialUrl, {});
}
- _pendingChannels.addAll(creationParams.javascriptChannelNames);
}
/// Returns [FuchsiaWebServices]
@@ -128,7 +135,9 @@
Set<String> javascriptChannelNames) async {
for (final channelName in javascriptChannelNames) {
if (_javascriptChannelSubscriptions.containsKey(channelName)) {
- await _javascriptChannelSubscriptions[channelName].cancel();
+ await _javascriptChannelSubscriptions[channelName]
+ .subscription
+ .cancel();
_javascriptChannelSubscriptions.remove(channelName);
await fuchsiaWebServices
.evaluateJavascript(['*'], 'window.$channelName = undefined;');
@@ -157,7 +166,7 @@
/// Close all remaining subscriptions and connections.
void dispose() {
for (final entry in _javascriptChannelSubscriptions.entries) {
- entry.value.cancel();
+ entry.value.subscription.cancel();
}
fuchsiaWebServices.dispose();
}
@@ -170,14 +179,19 @@
_currentUrl = state.url;
}
if (state.isMainDocumentLoaded != null && state.isMainDocumentLoaded) {
- final channelsToAdd =
- _pendingChannels.union(_javascriptChannelSubscriptions.keys.toSet());
- await _createChannelSubscriptions(channelsToAdd);
- _pendingChannels.clear();
+ await _establishCommunication(_beforeLoadChannels);
_platformCallbacksHandler.onPageFinished(_currentUrl);
}
}
+ /// Registers the javascript channels that will be loaded when the page loads.
+ /// Connection will be established when the page loads.
+ Future<void> _addBeforeLoadChannels(
+ Set<String> javascriptChannelNames) async {
+ _beforeLoadChannels = javascriptChannelNames;
+ await _createChannelSubscriptions(javascriptChannelNames, beforeLoad: true);
+ }
+
/// For each channel in [javascriptChannelNames] creates an object with the
/// channel name on window in the frame. That object will contain a
/// `postMessage` method. Messages sent through that method will be received
@@ -189,55 +203,85 @@
/// 3. The frame has a listener on window and will reply with a
/// share-port-ack and a port to which the frame will send messages.
/// 4. Bind that port and start listening on it.
- /// 5. When a message arrives on that port it is sent to the client through
+ /// 5. Notify the frame that we are ready to receive messages.
+ /// 6. When a message arrives on that port it is sent to the client through
/// the platform callback.
- Future<void> _createChannelSubscriptions(
- Set<String> javascriptChannelNames) async {
+ Future<void> _createChannelSubscriptions(Set<String> javascriptChannelNames,
+ {bool beforeLoad}) async {
for (final channelName in javascriptChannelNames) {
// Close any connections to that object (if any existed)
if (_javascriptChannelSubscriptions.containsKey(channelName)) {
- await _javascriptChannelSubscriptions[channelName].cancel();
+ await _javascriptChannelSubscriptions[channelName]
+ .subscription
+ .cancel();
+ } else {
+ _javascriptChannelSubscriptions[channelName] =
+ _ChannelSubscription(_nextId);
+ _nextId += 1;
}
+ }
- // Create a JavaScript object with one postMessage method. This object
- // will be exposed on window.$channelName when the FIDL communication is
- // established. Any window.$channelName already set will be removed.
- final script = _scriptForChannel(channelName);
- await evaluateJavascript(script);
+ // Create a JavaScript object with one postMessage method. This object
+ // will be exposed on window.$channelName when the FIDL communication is
+ // established. Any window.$channelName already set will be removed.
+ // If before load, the connection will happen once the page loads.
+ if (beforeLoad) {
+ await Future.wait(javascriptChannelNames.map((channel) {
+ // Reason: not supported until v2.2 and we need to support earlier
+ // versions.
+ // ignore: prefer_collection_literals
+ final script = _scriptForChannels(Set.from([channel]));
+ return fuchsiaWebServices.evaluateJavascriptBeforeLoad(
+ _javascriptChannelSubscriptions[channel].id, ['*'], script);
+ }));
+ return;
+ }
+ final script = _scriptForChannels(javascriptChannelNames);
+ await evaluateJavascript(script);
+
+ await _establishCommunication(javascriptChannelNames);
+ }
+
+ Future<void> _establishCommunication(Set<String> javascriptChannelNames) {
+ return Future.wait(javascriptChannelNames.map((channelName) async {
// Creates the message channel connection.
fidl_web.MessagePortProxy incomingPort;
try {
- incomingPort = await _bindIncomingPort();
+ incomingPort = await _bindIncomingPort(channelName);
} on Exception catch (e) {
log.warning('Failed to bind incoming port for $channelName: $e');
- continue;
+ return;
}
// Subscribe for incoming messages.
final incomingMessagesStream = _startReceivingMessages(incomingPort);
- _javascriptChannelSubscriptions[channelName] =
+ _javascriptChannelSubscriptions[channelName].subscription =
incomingMessagesStream.listen(
(message) async {
_platformCallbacksHandler.onJavaScriptChannelMessage(
channelName, message);
},
);
- }
+
+ // Notify of readiness
+ await fuchsiaWebServices.postMessage(
+ '*', 'share-port-$channelName-ready');
+ }));
}
- /// Communicates with the script injected by `_scriptForChannel` to get a port
+ /// Communicates with the script injected by `_scriptForChannels` to get a port
/// from the web page with which to communicate with the page. See comments on
/// `_createChannelSubscriptions` for details on the process.
- Future<fidl_web.MessagePortProxy> _bindIncomingPort() async {
+ Future<fidl_web.MessagePortProxy> _bindIncomingPort(String channel) async {
final messagePort = fidl_web.MessagePortProxy();
- await fuchsiaWebServices.postMessage('*', 'share-port',
+ await fuchsiaWebServices.postMessage('*', 'share-port-$channel',
outgoingMessagePortRequest: messagePort.ctrl.request());
final msg = await messagePort.receiveMessage();
final ackMsg = utils.bufferToString(msg.data);
- if (ackMsg != 'share-port-ack') {
- throw Exception('Expected "share-port-ack", got: "$ackMsg"');
+ if (ackMsg != 'share-port-ack-$channel') {
+ throw Exception('Expected "share-port-ack-$channel", got: "$ackMsg"');
}
if (msg.incomingTransfer == null || msg.incomingTransfer.isEmpty) {
throw Exception('failed to provide an incoming message port');
@@ -250,34 +294,57 @@
/// Script injected to the frame to create an object with the given name on
/// window. See comments on `_createChannelSubscriptions` for details on the
/// process.
- String _scriptForChannel(String channelName) {
- return """
+ String _scriptForChannels(Set<String> channelNames) {
+ return channelNames.map((channel) => '''
(function() {
- function init$channelName(event) {
- if (event.data == 'share-port' && event.ports && event.ports.length > 0) {
- console.log("Registering channel $channelName");
- const messageChannel = new MessageChannel();
- event.ports[0].postMessage('share-port-ack', [messageChannel.port2]);
- window.$channelName = new $channelName(messageChannel);
- window.removeEventListener('message', init$channelName, true);
- }
- }
-
- window.addEventListener('message', init$channelName, true);
-
- class $channelName {
- constructor(messageChannel) {
- this._messageChannel = messageChannel;
+ class $channel {
+ constructor() {
+ this._messageChannel = null;
+ this._pendingMessages = [];
+ this._isReady = false;
}
postMessage(message) {
- this._messageChannel.port1.postMessage(message);
+ if (this._isReady) {
+ this._messageChannel.port1.postMessage(message);
+ } else {
+ this._pendingMessages.push(message);
+ }
+ }
+
+ _ready() {
+ for (const pendingMessage of this._pendingMessages) {
+ this._messageChannel.port1.postMessage(pendingMessage);
+ }
+ this._isReady = true;
+ this._pendingMessages = [];
+ }
+
+ _setMessageChannel(channel) {
+ this._messageChannel = channel;
}
}
- window.$channelName = undefined;
+ window.$channel = new $channel();
+
+ function initializer$channel(event) {
+ if (event.data) {
+ if (event.data == 'share-port-$channel' && event.ports && event.ports.length > 0) {
+ console.log('Registering channel $channel');
+ const messageChannel = new MessageChannel();
+ window.$channel._setMessageChannel(messageChannel);
+ event.ports[0].postMessage('share-port-ack-$channel', [messageChannel.port2]);
+ }
+ if (event.data == 'share-port-$channel-ready') {
+ console.log('Channel $channel ready');
+ window.$channel._ready();
+ window.removeEventListener('message', initializer$channel, true);
+ }
+ }
+ }
+ window.addEventListener('message', initializer$channel, true);
})();
- """;
+ ''').join('\n');
}
/// Listens for messages on the incoming port and streams them.
diff --git a/public/dart/fuchsia_webview_flutter/lib/src/utils.dart b/public/dart/fuchsia_webview_flutter/lib/src/utils.dart
index e0d18ea..72d7027 100644
--- a/public/dart/fuchsia_webview_flutter/lib/src/utils.dart
+++ b/public/dart/fuchsia_webview_flutter/lib/src/utils.dart
@@ -13,3 +13,9 @@
dataVmo.close();
return utf8.decode(data.bytesAsUint8List());
}
+
+/// Writes a string into a VMO and a FIDL transport buffer.
+fidl_mem.Buffer stringToBuffer(String string) {
+ final vmo = SizedVmo.fromUint8List(utf8.encode(string));
+ return fidl_mem.Buffer(vmo: vmo, size: vmo.size);
+}
