I'm working on a Flash game that needs to call some Javascript on the page and get data back from it. Calling Javascript from Flash works. Calling the Flash functions from Javascript (often) doesn't.
I'm using the Gaia framework.
What happens:
ExternalInterface.call()
to call a Javascript function. This works.
ExternalInterface.addCallback()
.TypeError: myFlash.testCallback is not a function
.addCallback()
. Gaia and some of its included libraries use addCallback()
, and calling those functions from Javascript also produces the TypeError.addCallback()
periodically doesn't solve the errorExternalInterface.available = true
and ExternalInterface.objectID
contains the correct name for the Flash embed object.document.getElementById('myflashcontent')
correctly returns the Flash embed object.Edited to add:
ExternalInterface.addCallback()
are wrapped in a try...catch
block. When the JS error occurs, the catch
block is not triggered. It's a silent failure.allowScriptAccess = always
.flash.system.Security.allowDomain("mydomain")
doesn't fix the error.From my Page class:
public class MyPage extends AbstractPage
{
// declarations of stage instances and class variables
// other functions
override public function transitionIn():void
{
send_button.addEventListener(MouseEvent.MOUSE_UP, callJS);
exposeCallbacks();
super.transitionIn();
}
private function exposeCallbacks():void
{
trace("exposeCallbacks()");
if (ExternalInterface.available) {
trace("ExternalInterface.objectID: " + ExternalInterface.objectID);
try {
ExternalInterface.addCallback("testCallback", simpleTestCallback);
trace("called ExternalInterface.addCallback");
}
catch (error:SecurityError) {
trace("A SecurityError occurred: " + error.message + "\n");
}
catch (error:Error) {
trace("An Error occurred: " + error.message + "\n");
}
}
else {
trace("exposeCallbacks() - ExternalInterface not available");
}
}
private function simpleTestCallback(str:String):void
{
trace("simpleTestCallback(str=\"" + str + "\")");
}
private function callJS(e:Event):void
{
if (ExternalInterface.available) {
ExternalInterface.call("sendTest", "name", "url");
}
else {
trace("callJS() - ExternalInterface not available");
}
}
}
My Javascript:
function sendTest(text, url) {
var myFlash = document.getElementById("myflashcontent");
var callbackStatus = "";
callbackStatus += '\nmyFlash[testCallback]: ' + myFlash['testCallback'];
//console.log(callbackStatus);
var errors = false;
try {
myFlash.testCallback("test string");
}
catch (err) {
alert("Error: " + err.toString());
error = true;
}
if (!error) {
alert("Success");
}
}
var params = {
quality: "high",
scale: "noscale",
wmode: "transparent",
allowscriptaccess: "always",
bgcolor: "#000000"
};
var flashVars = {
siteXML: "xml/site.xml"
};
var attributes = {
id: "myflashcontent",
name: "myflashcontent"
};
// load the flash movie.
swfobject.embedSWF("http://myurl.com/main.swf?v2", "myflashcontent",
"728", "676", "10.0.0", serverRoot + "expressInstall.swf",
flashVars, params, attributes, function(returnObj) {
console.log('Returned ' + returnObj.success);
if (returnObj.success) { returnObj.ref.focus(); }
});
Calls made to JS via ExternalInterface are wrapped within a try { }
block and that causes subsequent JS errors to get suppressed.
A workaround for the same is to cause a function closure in JavaScript and execute the actual code after a timeout.
Example:
function myFnCalledByEI (arg1, arg2) {
setTimeout(myActualFunction () {
// You can use arg1 and arg2 here as well!
// Errors raised within this function will not be
// suppressed.
}, 0);
};
Here was our scenario once we narrowed down all the conditions:
In this specific scenario, ExternalInterface.call() would not fire right away. It only worked after creating a tiny delay with Timer class.
If we made wmode=window, or removed the alert() - everything worked. Try using console.log() to display debug text in firebug.
The other gotcha? Whether your js function returns an array or object vs a string. Surprisingly returning the native js array was interpreted by an array in Flash. Try outputting info about your return data like this:
var myRetVal = flash.external.ExternalInterface.call("my_js_func");
debug_txt.text = flash.utils.describeType(myRetVal).toString();
This might be similar to the issue you are experiencing.
http://www.google.com/support/forum/p/translator-toolkit-api/thread?tid=58cda1b34ae1e944&hl=en
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