dart-sdk/client/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.

// 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(receivePort) {
  this.receivePort = receivePort;
}

function ReceivePortSync() {
  this.id = ReceivePortSync.id++;
  ReceivePortSync.map[this.id] = this;
}

ReceivePortSync.id = 0;
ReceivePortSync.map = {};

ReceivePortSync.prototype.receive = function(callback) {
  this.callback = callback;
};

ReceivePortSync.prototype.toSendPort = function() {
  return new SendPortSync(this);
};

ReceivePortSync.prototype.close = function() {
  delete ReceivePortSync.map[this.id];
};

// TODO(kasperl): Hide these serialization methods so they
// do not clutter up the global scope.
function _serialize(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 SendPortSync) {
    return [ 'sendport', message.receivePort.id ];
  } else {
    var id = 0;
    var keys = Object.getOwnPropertyNames(message);
    var values = new Array(keys.length);
    for (var i = 0; i < keys.length; i++) {
      values[i] = message[keys[i]];
    }
    return [ 'map', id, keys, values ];
  }
}

function _deserialize(message) {
  return _deserializeHelper(message);
}

function _deserializeHelper(x) {
  if (x == null ||
      typeof(x) == 'string' ||
      typeof(x) == 'number' ||
      typeof(x) == 'boolean') {
    return x;
  }
  switch (x[0]) {
    case 'map': return _deserializeMap(x);
    default: throw 'unimplemented';
  }
}

function _deserializeMap(x) {
  var result = { };
  var id = x[1];
  var keys = x[2];
  var values = x[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 registerPort(name, port) {
  var stringified = JSON.stringify(_serialize(port));
  window.localStorage['dart-port:' + name] = stringified;
}

if (navigator.webkitStartDart) {
  window.addEventListener('js-sync-message', function(event) {
    var data = JSON.parse(event.data);
    var deserialized = _deserialize(data.message);
    var result = ReceivePortSync.map[data.id].callback(deserialized);
    var string = JSON.stringify(_serialize(result));
    var event = document.createEvent('TextEvent');
    event.initTextEvent('js-result', false, false, window, string);
    window.dispatchEvent(event);
  }, false);
}