When I first started using ScriptingBridge I struggled with a similar
problem (iTunes add: wants an NSArray - an array of what ? It turns
out it needs an array of NSURL's).
Actually, the iTunes dictionary specifies a list of aliases
(typeAlias) for the 'add' command, but as long as the command is well-
implemented (i.e. asks the Apple Event Manager to coerce the supplied
values to the desired type) it should be able to accept file URLs
(typeFileURL) as well. Cocoa doesn't provide an equivalent to Carbon's
Alias type, and Scripting Bridge doesn't define an equivalent class
itself, so I'm assuming it just uses NSURLs in both cases.
To debug this I ran the Script Editor app 'in debug mode' with a small
handwritten script to mirror my action. To do this set the AEDebugSend
environment variable in a Terminal window and then launch the script
editor app from the same terminal session. ScriptEditor will log to
stdout a dump of the raw events it was sending to iTunes - I could see
that my posix path was being converted to an 'furl' applevent and from
their I deduced the NSURL requirement.
Crap documentation tools is certainly one of Scripting Bridge's
various shortcomings. Unfortunately, Apple haven't published the rules
by which Scripting Bridge translates AppleScript-style keywords and
Apple event types to their ObjC equivalents, otherwise I could add a
'Scripting Bridge' option to ASDictionary [1] which can already export
very nice HTML-based application dictionaries for AppleScript and
Python/Ruby/ObjC-appscript.
However, you shouldn't need to resort to AEDebug to determine type
info (except perhaps as a last resort): if you look at the
application's dictionary in Script Editor/Smile/Script Debugger/
ASDictionary, you can probably guess the desired Cocoa class based on
the AppleScript type shown - e.g. 'list of Unicode text' would be an
NSArray of NSStrings; 'list of integer' would presumably be an NSArray
of NSNumbers; etc.
You might also want to file a feature request asking that sdp-
generated headers add a full type description to the comments of
properties and parameters, e.g.:
- (itunesTrack *) add:(NSArray *)/*of NSURL*/ x to:(SBObject
*)to; // add one or more files to a playlist
(Incidentally, while on the topic of SB sins, be warned that iTunes'
'add' command will return either a reference OR a list of references,
depending on the number of files you give it. Unfortunately, the
iTunes dictionary is somewhat imprecise in describing the return type,
so the above sdp-generated declaration ends up with the wrong result
type.)
