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ActionScript: JavaScript Event Handlers for JW Player

JW Player has a rich JavaScript API. One of the things you can do is to create JavaScript event handlers for ActionScript events. However, there are a few things that can bite you in the butt if you don't keep them in mind.

First of all, as the documentation points out, you can't set an event handler until JW Player is ready for it. If you set it too early, it won't work, and you won't even get an error message. If you have a function called playerReady, it'll automatically be called by JW Player. That's a great place to setup your handlers.

Next, when JW Player calls playerReady, it's supposed to pass an obj containing the ID for the HTML DOM object. In my experience, it doesn't. Hence, you have to lookup the object manually. See my previous post about the fact that you can't use jQuery's $() to lookup the object, but should instead stick with document.getElementById.

Last of all, remember that when you give JW Player your JavaScript callback, you have to pass the function's name as a string. It feels natural to pass a function pointer or even to have an inline function, but that doesn't work (nor will you get an error message).

In summary, here's the code:
function playerReady(obj) {
document.getElementById('player-embed').addModelListener(
"TIME", "handleTimeEvent");
}

function handleTimeEvent(e) {
console.log(window.timeEvent.duration);
console.log(window.timeEvent.position);
}

Comments

Jeroen Wijering said…
Thanks for your posting. You totally confirm what we feel to be the "pain points" in our current API. Unfortunately, these issues directly relate to communication restrictions on a lower level, between actionscript and javascript.

For the next release of the Flash version of our player (5.3), we are working on a dedicated javascript wrapper (something like SWFObject) that will work around these issues:

*) Listeners assigned before the player is "ready" will be queued up by the wrapper.
*) Support for jQuery will be added.
*) Function references will be translated to strings inside the library.

Would love to hear any other suggestions people have for improving our javascript API!
dan said…
hmm, can't an error message be generated that is kept as an internal string if you try to set an event handler too early and then when the player is all set up it get then log the internal string?
Hi, Jeroen, thanks for your response!

I'm not actually complaining ;) I've had a much harder time coping with Boxee than I have coping with JW Player. About the only thing that really sticks out to me about JW Player's JavaScript API is that obj["id"] doesn't work as promised in playerReady.

> Unfortunately, these issues directly relate to communication restrictions on a lower level, between actionscript and javascript.

Yep, that's what I figured.
Xenode_Blogger said…
This comment has been removed by the author.
José Manuel said…
Hi, I have a BIG QUESTION: ¿How do I "execute" an actionscript function? I have to execute it in order to get a decrypted URL by changing some variables... the thing is:

1) You have an URL

2) Somehow it pass trough a function
and it returns it a different result in base of the function's work. BUT I DON'T KNOW HOW TO EXECUTE IT!! ¿Can you help me?
You're going to have to modify the source code for JW Player itself. Take a look at the file named JavascriptCompatibilityAPI.as, especially the calls to ExternalInterface.addCallback.