package bridge
{
import flash.external.ExternalInterface;
import flash.util.*;
import flash.events.*;
import flash.display.*;
import mx.controls.Alert;
import mx.core.IMXMLObject;
public class FABridge implements IMXMLObject
{
public function FABridge()
{
initializeCallbacks();
}
/** stores a cache of descriptions of AS types suitable for sending to JS */
private var localTypeMap:Object = {};
/** stores an id-referenced dictionary of objects exported to JS */
private var localInstanceMap:Object = {};
/** stores an id-referenced dictionary of functions exported to JS */
private var localFunctionMap:Object = {};
/** stores an id-referenced dictionary of proxy functions imported from JS */
private var remoteFunctionCache:Object = {}
/** a local counter for generating unique IDs */
private var nextID:Number = 0;
/** values that can't be serialized natively across the bridge are packed and identified by type.
* These constants represent different serialization types */
private static const TYPE_ASINSTANCE:uint = 1;
private static const TYPE_ASFUNCTION:uint = 2;
private static const TYPE_JSFUNCTION:uint = 3;
private static const TYPE_ANONYMOUS:uint = 4;
private var _initChecked:Boolean = false;
public function get rootObject():DisplayObject {return _rootObject;}
public function set rootObject(value:DisplayObject):void
{
_rootObject = value;
checkInitialized();
}
public var bridgeName:String;
private var _registerComplete:Boolean = false;
/** attaches the callbacks to external interface */
public function initializeCallbacks():void
{
if (ExternalInterface.available == false)
return;
ExternalInterface.addCallback("getRoot",js_getRoot);
ExternalInterface.addCallback("getPropFromAS",js_getPropFromAS);
ExternalInterface.addCallback("setPropInAS",js_setPropertyInAS);
ExternalInterface.addCallback("invokeASMethod",js_invokeMethod);
ExternalInterface.addCallback("invokeASFunction",js_invokeFunction);
ExternalInterface.addCallback("releaseASObjects",js_releaseASObjects);
ExternalInterface.addCallback("create",js_create);
}
private var _rootObject:DisplayObject;
private var _document:DisplayObject;
public function initialized(document:Object, id:String):void
{
_document = (document as DisplayObject);
if(_document != null)
checkInitialized();
}
private function get baseObject():DisplayObject
{
return (rootObject == null)? _document:rootObject;
}
private function checkInitialized()
{
if(_initChecked== true)
return;
_initChecked = true;
var t:Timer = new Timer(200,1);
t.addEventListener(TimerEvent.TIMER,auxCheckInitialized);
t.start();
}
private function auxCheckInitialized(e:Event) {
var bCanGetParams:Boolean = true;
try {
var params:Object = baseObject.root.loaderInfo.parameters;
}
catch(e:Error) {
bCanGetParams = false;
}
if(bCanGetParams == false)
{
var t:Timer = new Timer(100);
var timerFunc:Function = function(e:TimerEvent)
{
if(baseObject.root != null) {
try {
var params:Object = baseObject.root.loaderInfo.parameters;
}
catch(e:Error) {
bCanGetParams = false;
}
if(bCanGetParams)
{
t.removeEventListener(TimerEvent.TIMER,timerFunc);
t.stop();
dispatchInit();
}
}
}
t.addEventListener(TimerEvent.TIMER,timerFunc);
t.start();
}
else
{
dispatchInit();
}
}
private function dispatchInit(e:Event = null)
{
if(_registerComplete == true)
return;
if (ExternalInterface.available == false)
return;
if( bridgeName == null)
{
bridgeName = baseObject.root.loaderInfo.parameters["bridgeName"];
if(bridgeName == null)
{
bridgeName = "flash";
}
}
_registerComplete = ExternalInterface.call("FABridge__bridgeInitialized",[bridgeName]);
}
/** serializes a value for transfer across the bridge. primitive types are left as is. Arrays are left as arrays, but individual
* values in the array are serialized according to their type. Functions and class instances are inserted into a hash table and sent
* across as keys into the table.
*
* For class instances, if the instance has been sent before, only its id is passed. If This is the first time the instance has been sent,
* a ref descriptor is sent associating the id with a type string. If this is the first time any instance of that type has been sent
* across, a descriptor indicating methods, properties, and variables of the type is also sent across
*/
public function serialize(value:*):*
{
var result:* = {};
result.newTypes = [];
result.newRefs = {};
if(value is Number || value is Boolean || value is String || value == null || value == undefined || value is int || value is uint) {
result = value;
}
else if (value is Array)
{
result = [];
for(var i:int=0;i<value.length;i++) {
result[i] = serialize(value[i]);
}
}
else if (value is Function)
{
result.type = TYPE_ASFUNCTION;
result.value = getFunctionID(value,true);
}
else if (getQualifiedClassName(value) == "Object")
{
result.type = TYPE_ANONYMOUS;
result.value = value;
}
else
{
result.type = TYPE_ASINSTANCE;
var className:String = getQualifiedClassName(value);
if(retrieveCachedTypeDescription(className,false) == null) {
result.newTypes.push(retrieveCachedTypeDescription(className,true));
}
var objRef:Number = getRef(value,false);
if(isNaN(objRef)) {
objRef = getRef(value,true);
result.newRefs[objRef] = className;
}
result.value = objRef;
}
return result;
}
/** deserializes a value passed in from javascript. See serialize for details on how values are packed and
* unpacked for transfer across the bridge.
*/
public function deserialize(valuePackage:*):*
{
var result:*;
if(valuePackage is Number || valuePackage is Boolean || valuePackage is String || valuePackage == null || valuePackage == undefined || valuePackage is int || valuePackage is uint)
{
result = valuePackage;
}
else if(valuePackage is Array)
{
result = [];
for(var i:int = 0;i<valuePackage.length;i++)
{
result[i] = deserialize(valuePackage[i]);
}
}
else if (valuePackage.type == FABridge.TYPE_JSFUNCTION)
{
result = getRemoteFunctionProxy(valuePackage.value,true);
}
else if (valuePackage.type == FABridge.TYPE_ASFUNCTION)
{
throw new Error("as functions can't be passed back to as yet");
}
else if (valuePackage.type == FABridge.TYPE_ASINSTANCE)
{
result = resolveRef(valuePackage.value);
}
else if (valuePackage.type == FABridge.TYPE_ANONYMOUS)
{
result = valuePackage.value;
}
return result;
}
/** retrieves a type description for the type indicated by className, building one and caching it if necessary */
public function retrieveCachedTypeDescription(className:String,createifNecessary:Boolean):Object
{
if(localTypeMap[className] == null && createifNecessary == true)
{
localTypeMap[className] = buildTypeDescription(className);
}
return localTypeMap[className];
}
/** builds a type description for the type indiciated by className */
public function buildTypeDescription(className:String):Object
{
var desc:Object = {};
className = className.replace(/::/,".");
var objClass:Class = getClassByName(className);
var xData:XML = describeType(objClass);
desc.name = xData.@name.toString();
var methods:Array = [];
var xMethods:XMLList = xData.factory.method;
for(var i:int = 0;i < xMethods.length();i++) {
methods.push(xMethods[i].@name.toString());
}
desc.methods = methods;
var accessors:Array = [];
var xAcc:XMLList = xData.factory.accessor;
for(var i:int = 0;i < xAcc.length();i++) {
accessors.push(xAcc[i].@name.toString());
}
xAcc = xData.factory.variable;
for(var i:int = 0;i < xAcc.length();i++) {
accessors.push(xAcc[i].@name.toString());
}
desc.accessors = accessors;
return desc;
}
/** resolves an instance id passed from JS to an instance previously cached for representing in JS*/
private function resolveRef(objRef:Number):Object
{
return (objRef == -1)? baseObject:localInstanceMap[objRef];
}
/** returns an id associated with the object provided for passing across the bridge to JS */
private function getRef(obj:Object,createIfNecessary:Boolean):Number
{
var ref:Number;
if(createIfNecessary)
{
var newRef:Number = nextID++;
localInstanceMap[newRef] = obj;
ref = newRef;
}
return ref;
}
/** resolves a function ID passed from JS to a local function previously cached for representation in JS */
private function resolveFunctionID(funcID:Number):Function
{
return localFunctionMap[funcID];
}
/** associates a unique ID with a local function suitable for passing across the bridge to proxy in Javascript */
public function getFunctionID(f:Function,createIfNecessary:Boolean):Number
{
var ref:Number;
if(createIfNecessary)
{
var newID:Number = nextID++;
localFunctionMap[newID] = f;
ref = newID;
}
return ref;
}
/** returns a proxy function that represents a function defined in javascript. This function can be called syncrhonously, and will
* return any values returned by the JS function */
public function getRemoteFunctionProxy(functionID:Number,createIfNecessary:Boolean):Function
{
if (remoteFunctionCache[functionID] == null)
{
remoteFunctionCache[functionID] = function(...args):*
{
var externalArgs:Array = args.concat();
externalArgs.unshift(functionID);
ExternalInterface.call("FABridge__invokeJSFunction",serialize(externalArgs));
}
}
return remoteFunctionCache[functionID];
}
/** called to fetch a named property off the instanced assicated with objID */
public function js_getPropFromAS(objID:Number,propName:String):*
{
var obj:Object = resolveRef(objID);
return serialize(obj[propName]);
}
/** called to set a named property on the instance associated with objID */
private function js_setPropertyInAS(objID:Number,propRef:String,value:*):void
{
var obj:Object = resolveRef(objID);
obj[propRef] = deserialize(value);
}
/** accessor for retrieveing a proxy to the root object from JS */
private function js_getRoot():*
{
return serialize(baseObject);
}
/** called to invoke a function or closure associated with funcID */
private function js_invokeFunction(funcID:Number,args:Object):*
{
var result:*;
var func:Function = resolveFunctionID(funcID);
if(func != null)
result = func.apply(null,deserialize(args));
return serialize(result);
}
/** called ot invoke a named method on the object associated with objID */
private function js_invokeMethod(objID:Number,methodName:String,args:Object):*
{
var obj:Object = resolveRef(objID);
var result:*;
return serialize( obj[methodName].apply(null,deserialize(args)) );
}
private function js_releaseASObjects()
{
localTypeMap = {};
localInstanceMap = {};
localFunctionMap = {};
}
private function js_create(className:String):*
{
var c:Class = getClassByName(className);
var instance:Object = new c();
return serialize(instance);
}
}
}