Support compiling templates in the browser.

extension/dart.js

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// TODO(jacobr): copy this file from the correct pub directory rather than
+// manually copying it here once it is hosted in pub.
+// Bootstrap support for Dart scripts on the page as this script.
+if (navigator.webkitStartDart) {
+  if (!navigator.webkitStartDart()) {
+    document.body.innerHTML = 'This build has expired.  Please download a new Dartium at http://www.dartlang.org/dartium/index.html';
+  }
+} else {
+  // TODO:
+  // - Support in-browser compilation.
+  // - Handle inline Dart scripts.
+  window.addEventListener("DOMContentLoaded", function (e) {
+    // Fall back to compiled JS. Run through all the scripts and
+    // replace them if they have a type that indicate that they source
+    // in Dart code.
+    //
+    //   <script type="application/dart" src="..."></script>
+    //
+    var scripts = document.getElementsByTagName("script");
+    var length = scripts.length;
+    for (var i = 0; i < length; ++i) {
+      if (scripts[i].type == "application/dart") {
+        // Remap foo.dart to foo.dart.js.
+        if (scripts[i].src && scripts[i].src != '') {
+          var script = document.createElement('script');
+          script.src = scripts[i].src + '.js';
+          var parent = scripts[i].parentNode;
+          parent.replaceChild(script, scripts[i]);
+        }
+      }
+    }
+  }, false);
+}
+
+// ---------------------------------------------------------------------------
+// Experimental support for JS interoperability
+// ---------------------------------------------------------------------------
+function SendPortSync() {
+}
+
+function ReceivePortSync() {
+  this.id = ReceivePortSync.id++;
+  ReceivePortSync.map[this.id] = this;
+}
+
+(function() {
+  // Serialize the following types as follows:
+  //  - primitives / null: unchanged
+  //  - lists: [ 'list', internal id, list of recursively serialized elements ]
+  //  - maps: [ 'map', internal id, map of keys and recursively serialized values ]
+  //  - send ports: [ 'sendport', type, isolate id, port id ]
+  //
+  // Note, internal id's are for cycle detection.
+  function serialize(message) {
+    var visited = [];
+    function checkedSerialization(obj, serializer) {
+      // Implementation detail: for now use linear search.
+      // Another option is expando, but it may prohibit
+      // VM optimizations (like putting object into slow mode
+      // on property deletion.)
+      var id = visited.indexOf(obj);
+      if (id != -1) return [ 'ref', id ];
+      var id = visited.length;
+      visited.push(obj);
+      return serializer(id);
+    }
+
+    function doSerialize(message) {
+      if (message == null) {
+        return null;  // Convert undefined to null.
+      } else if (typeof(message) == 'string' ||
+                 typeof(message) == 'number' ||
+                 typeof(message) == 'boolean') {
+        return message;
+      } else if (message instanceof Array) {
+        return checkedSerialization(message, function(id) {
+          var values = new Array(message.length);
+          for (var i = 0; i < message.length; i++) {
+            values[i] = doSerialize(message[i]);
+          }
+          return [ 'list', id, values ];
+        });
+      } else if (message instanceof LocalSendPortSync) {
+        return [ 'sendport', 'nativejs', message.receivePort.id ];
+      } else if (message instanceof DartSendPortSync) {
+        return [ 'sendport', 'dart', message.isolateId, message.portId ];
+      } else {
+        return checkedSerialization(message, function(id) {
+          var keys = Object.getOwnPropertyNames(message);
+          var values = new Array(keys.length);
+          for (var i = 0; i < keys.length; i++) {
+            values[i] = doSerialize(message[keys[i]]);
+          }
+          return [ 'map', id, keys, values ];
+        });
+      }
+    }
+    return doSerialize(message);
+  }
+
+  function deserialize(message) {
+    return deserializeHelper(message);
+  }
+
+  function deserializeHelper(message) {
+    if (message == null ||
+        typeof(message) == 'string' ||
+        typeof(message) == 'number' ||
+        typeof(message) == 'boolean') {
+      return message;
+    }
+    switch (message[0]) {
+      case 'map': return deserializeMap(message);
+      case 'sendport': return deserializeSendPort(message);
+      case 'list': return deserializeList(message);
+      default: throw 'unimplemented';
+    }
+  }
+
+  function deserializeMap(message) {
+    var result = { };
+    var id = message[1];
+    var keys = message[2];
+    var values = message[3];
+    for (var i = 0, length = keys.length; i < length; i++) {
+      var key = deserializeHelper(keys[i]);
+      var value = deserializeHelper(values[i]);
+      result[key] = value;
+    }
+    return result;
+  }
+
+  function deserializeSendPort(message) {
+    var tag = message[1];
+    switch (tag) {
+      case 'nativejs':
+        var id = message[2];
+        return new LocalSendPortSync(ReceivePortSync.map[id]);
+      case 'dart':
+        var isolateId = message[2];
+        var portId = message[3];
+        return new DartSendPortSync(isolateId, portId);
+      default:
+        throw 'Illegal SendPortSync type: $tag';
+    }
+  }
+
+  function deserializeList(message) {
+    var values = message[2];
+    var length = values.length;
+    var result = new Array(length);
+    for (var i = 0; i < length; i++) {
+      result[i] = deserializeHelper(values[i]);
+    }
+    return result;
+  }
+
+  window.registerPort = function(name, port) {
+    var stringified = JSON.stringify(serialize(port));
+    window.localStorage['dart-port:' + name] = stringified;
+  };
+
+  window.lookupPort = function(name) {
+    var stringified = window.localStorage['dart-port:' + name];
+    return deserialize(JSON.parse(stringified));
+  };
+
+  ReceivePortSync.id = 0;
+  ReceivePortSync.map = {};
+
+  ReceivePortSync.dispatchCall = function(id, message) {
+    // TODO(vsm): Handle and propagate exceptions.
+    var deserialized = deserialize(message);
+    var result = ReceivePortSync.map[id].callback(deserialized);
+    return serialize(result);
+  };
+
+  ReceivePortSync.prototype.receive = function(callback) {
+    this.callback = callback;
+  };
+
+  ReceivePortSync.prototype.toSendPort = function() {
+    return new LocalSendPortSync(this);
+  };
+
+  ReceivePortSync.prototype.close = function() {
+    delete ReceivePortSync.map[this.id];
+  };
+
+  if (navigator.webkitStartDart) {
+    window.addEventListener('js-sync-message', function(event) {
+      var data = JSON.parse(getPortSyncEventData(event));
+      var deserialized = deserialize(data.message);
+      var result = ReceivePortSync.map[data.id].callback(deserialized);
+      // TODO(vsm): Handle and propagate exceptions.
+      dispatchEvent('js-result', serialize(result));
+    }, false);
+  }
+
+  function LocalSendPortSync(receivePort) {
+    this.receivePort = receivePort;
+  }
+
+  LocalSendPortSync.prototype = new SendPortSync();
+
+  LocalSendPortSync.prototype.callSync = function(message) {
+    // TODO(vsm): Do a direct deepcopy.
+    message = deserialize(serialize(message));
+    return this.receivePort.callback(message);
+  }
+
+  function DartSendPortSync(isolateId, portId) {
+    this.isolateId = isolateId;
+    this.portId = portId;
+  }
+
+  DartSendPortSync.prototype = new SendPortSync();
+
+  function dispatchEvent(receiver, message) {
+    var string = JSON.stringify(message);
+    var event = document.createEvent('CustomEvent');
+    event.initCustomEvent(receiver, false, false, string);
+    window.dispatchEvent(event);
+  }
+
+  function getPortSyncEventData(event) {
+    return event.detail;
+  }
+
+  DartSendPortSync.prototype.callSync = function(message) {
+    var serialized = serialize(message);
+    var target = 'dart-port-' + this.isolateId + '-' + this.portId;
+    // TODO(vsm): Make this re-entrant.
+    // TODO(vsm): Set this up set once, on the first call.
+    var source = target + '-result';
+    var result = null;
+    var listener = function (e) {
+      result = JSON.parse(getPortSyncEventData(e));
+    };
+    window.addEventListener(source, listener, false);
+    dispatchEvent(target, [source, serialized]);
+    window.removeEventListener(source, listener, false);
+    return deserialize(result);
+  }
+})();