add io_websocket transport for switching the implementation of dart.l…

…ibrary.html and dart.library.io on #4 Flutter Port

lib/src/engine/socket.dart

@@ -12,14 +12,21 @@ import 'dart:convert';
  *
  * Copyright (C) 2017 Potix Corporation. All Rights Reserved.
  */
-import 'dart:html';
+//import 'dart:html';
 
 import 'package:logging/logging.dart';
 import 'package:socket_io_common/src/util/event_emitter.dart';
 import 'package:socket_io_client/src/engine/parseqs.dart';
 import 'package:socket_io_common/src/engine/parser/parser.dart' as parser;
 import 'package:socket_io_client/src/engine/transport/polling_transport.dart';
-import 'package:socket_io_client/src/engine/transport/transports.dart';
+import './transport/transport.dart';
+
+// ignore: uri_does_not_exist
+import './transport/transports_stub.dart'
+// ignore: uri_does_not_exist
+if (dart.library.html) './transport/transports.dart'
+// ignore: uri_does_not_exist
+if (dart.library.io) './transport/io_transports.dart';
 
 final Logger _logger = new Logger('socket_io_client:engine.Socket');
 
@@ -80,7 +87,7 @@ class Socket extends EventEmitter {
       opts['hostname'] = Uri.parse(opts['host']).host;
     }
 
-    this.secure = opts['secure'] ?? (window.location.protocol == 'https:');
+    this.secure = opts['secure'] /*?? (window.location.protocol == 'https:')*/;
 
     if (opts['hostname'] != null && !opts.containsKey('port')) {
       // if no port is specified manually, use the protocol default
@@ -89,11 +96,11 @@ class Socket extends EventEmitter {
 
     this.agent = opts['agent'] ?? false;
     this.hostname =
-        opts['hostname'] ?? (window.location.hostname ?? 'localhost');
-    this.port = opts['port'] ??
+        opts['hostname'] /*?? (window.location.hostname ?? 'localhost')*/;
+    this.port = opts['port'] /*??
         (window.location.port.isNotEmpty
             ? int.parse(window.location.port)
-            : (this.secure ? 443 : 80));
+            : (this.secure ? 443 : 80))*/;
     var query = opts['query'] ?? {};
     if (query is String)
       this.query = decode(query);

lib/src/engine/transport/io_transports.dart

@@ -0,0 +1,19 @@
+// Copyright (C) 2019 Potix Corporation. All Rights Reserved 
+// History: 2019-01-21 12:15
+// Author: jumperchen<[email protected]>
+import 'package:socket_io_client/src/engine/transport/io_websocket_transport.dart';
+import 'package:socket_io_client/src/engine/transport/transport.dart';
+
+class Transports {
+  static List<String> upgradesTo(String from) {
+    if ("polling" == from) {
+      return ["websocket"];
+    }
+    return [];
+  }
+
+  static Transport newInstance(String name, options) {
+    // only support websocket here.
+    return new IOWebSocketTransport(options);
+  }
+}

lib/src/engine/transport/io_websocket_transport.dart

@@ -0,0 +1,169 @@
+// Copyright (C) 2019 Potix Corporation. All Rights Reserved 
+// History: 2019-01-21 12:13
+// Author: jumperchen<[email protected]>
+
+import 'dart:async';
+import 'dart:io';
+//import 'dart:html';
+import 'package:logging/logging.dart';
+import 'package:socket_io_client/src/engine/transport/transport.dart';
+import 'package:socket_io_common/src/engine/parser/parser.dart';
+import 'package:socket_io_client/src/engine/parseqs.dart';
+
+class IOWebSocketTransport extends Transport {
+  static Logger _logger =
+  new Logger('socket_io_client:transport.IOWebSocketTransport');
+
+  String name = 'websocket';
+  var protocols;
+
+  bool supportsBinary;
+  Map perMessageDeflate;
+  WebSocket ws;
+
+  IOWebSocketTransport(Map opts) : super(opts) {
+    var forceBase64 = (opts != null && opts['forceBase64']);
+    this.supportsBinary = !forceBase64;
+    this.perMessageDeflate = opts['perMessageDeflate'];
+    this.protocols = opts['protocols'];
+  }
+
+  void doOpen() async {
+    var uri = this.uri();
+    var protocols = this.protocols;
+
+    try {
+      this.ws = await WebSocket.connect(uri, protocols: protocols);
+    } catch (err) {
+      return this.emit('error', err);
+    }
+
+//    if (this.ws.binaryType == null) {
+//      this.supportsBinary = false;
+//    }
+//
+//    this.ws.binaryType = 'arraybuffer';
+
+    this.addEventListeners();
+  }
+
+  /**
+   * Adds event listeners to the socket
+   *
+   * @api private
+   */
+  void addEventListeners() {
+    bool isOpen = false;
+    this.ws.listen((data) {
+      if (isOpen != true) {
+        onOpen();
+        isOpen = true;
+      }
+      onData(data);
+    }, onDone:  () => onClose(), onError:  (_) => onError('websocket error'));
+  }
+
+  /**
+   * Writes data to socket.
+   *
+   * @param {Array} array of packets.
+   * @api private
+   */
+  write(List packets) {
+    this.writable = false;
+
+    var done = () {
+      emit('flush');
+
+      // fake drain
+      // defer to next tick to allow Socket to clear writeBuffer
+      Timer.run(() {
+        writable = true;
+        emit('drain');
+      });
+    };
+
+    int total = packets.length;
+    // encodePacket efficient as it uses WS framing
+    // no need for encodePayload
+    packets.forEach((packet) {
+      PacketParser.encodePacket(packet,
+          supportsBinary: supportsBinary, fromClient: true, callback: (data) {
+            // Sometimes the websocket has already been closed but the browser didn't
+            // have a chance of informing us about it yet, in that case send will
+            // throw an error
+            try {
+              // TypeError is thrown when passing the second argument on Safari
+              ws.add(data);
+            } catch (e) {
+              _logger.fine('websocket closed before onclose event');
+            }
+
+            if (--total == 0) done();
+          });
+    });
+  }
+
+  /**
+   * Closes socket.
+   *
+   * @api private
+   */
+  doClose() {
+    this.ws?.close();
+  }
+
+  /**
+   * Generates uri for connection.
+   *
+   * @api private
+   */
+  uri() {
+    var query = this.query ?? {};
+    var schema = this.secure ? 'wss' : 'ws';
+    var port = '';
+
+    // avoid port if default for schema
+    if (this.port != null &&
+        (('wss' == schema && this.port != 443) ||
+            ('ws' == schema && this.port != 80))) {
+      port = ':${this.port}';
+    }
+
+    // append timestamp to URI
+    if (this.timestampRequests == true) {
+      query[this.timestampParam] =
+          new DateTime.now().millisecondsSinceEpoch.toRadixString(36);
+    }
+
+    // communicate binary support capabilities
+    if (this.supportsBinary == false) {
+      query['b64'] = 1;
+    }
+
+    var queryString = encode(query);
+
+    // prepend ? to query
+    if (queryString.isNotEmpty) {
+      queryString = '?$queryString';
+    }
+
+    var ipv6 = this.hostname.contains(':');
+    return schema +
+        '://' +
+        (ipv6 ? '[' + this.hostname + ']' : this.hostname) +
+        port +
+        this.path +
+        queryString;
+  }
+//
+//  /**
+//   * Feature detection for WebSocket.
+//   *
+//   * @return {Boolean} whether this transport is available.
+//   * @api public
+//   */
+//  check() {
+//    return !!WebSocket && !('__initialize' in WebSocket && this.name === WS.prototype.name);
+//  }
+}

lib/src/engine/transport/polling_transport.dart

@@ -11,8 +11,8 @@ import 'package:socket_io_client/src/engine/parseqs.dart';
  *
  * Copyright (C) 2017 Potix Corporation. All Rights Reserved.
  */
-import 'package:socket_io_client/src/engine/transport/transports.dart';
 import 'package:logging/logging.dart';
+import 'package:socket_io_client/src/engine/transport/transport.dart';
 import 'package:socket_io_common/src/engine/parser/parser.dart';
 
 final Logger _logger = new Logger('socket_io:transport.PollingTransport');