Re: Problems with ScriptingBridge and iTunes

FROM : Christopher Nebel
DATE : Mon Mar 03 21:22:33 2008

On Mar 1, 2008, at 5:28 PM, Hannes Petri wrote:

> I want to retrieve the path to the currently played file in iTunes. 
> I thought scripting bridge would be the perfect tool for this, 
> however i've run into some problem. I have this code:
>
> iTunesApplication *iTunes = [[SBApplication alloc] 
> initWithBundleIdentifier:@"com.apple.iTunes"];
> iTunesTrack *currentTrack = [iTunes currentTrack];
>     
> if ([currentTrack isKindOfClass:[iTunesFileTrack class]]) {
>     …
> }
>
> The problem is, that the class of the object returned is _always_ 
> iTunesTrack, and not iTunesFileTrack, as i expect it to be.


As described in the Scripting Bridge Release Note under Lazy 
Evaluation (using precisely this as an example, no less), SBObjects 
are not evaluated until you either try to get some concrete data from 
them (e.g., "name"), or until you invoke -get.  "currentTrack" is 
nothing more or less than a reference to "the current track in 
iTunes".  If you want to find out precisely what it is *now*, do this:

   iTunesTrack *currentTrack = [[iTunes currentTrack] get];

-isKindOfClass: will then give you the answer you seek.


--Chris Nebel
AppleScript Engineering