How do I fix my AppleScript to delete a selection of tracks in iTunes?

Question

I've created the following AppleScript for deleting all the selected tracks:

property okflag : false

-- check if iTunes is running 
tell application "Finder"
    if (get name of every process) contains "iTunes" then set okflag to true
end tell
if okflag then
    tell application "iTunes"
        if selection is not {} then
            repeat with this_track in selection
                try
                    try
                        set cla to class of this_track
                        set floc to (get location of this_track)
                        delete this_track
                    on error error_message number error_number
                        display alert error_message message ("Error number: ") & error_number & "."
                    end try
                    if cla is file track then
                        my delete_the_file(floc)
                    end if
                end try
            end repeat
        end if
    end tell
end if

to delete_the_file(floc)
    try
        -- tell application "Finder" to delete floc
        do shell script "mv " & quoted form of POSIX path of (floc as string) & " " & quoted form of POSIX path of (path to trash as string)
    on error
        display dialog "Track deleted, but could not be moved to trash" buttons {"Hmm"} default button 1 with icon 1
    end try
end delete_the_file

It works fine when I select a single item, but when I select more than one I get: "Can't get location of item 2 of selection" (error number -1728). I believe this is because by deleting a track, the script's index into the selection is corrupted.

I thought I'd try making my own list of tracks to be deleted first:

tell application "iTunes"
    if selection is not {} then
        set to_delete to {}
        repeat with this_track in selection
            try
                set cla to class of this_track
                set floc to (get location of this_track)
                if cla is file track then
                    set pair to {this_track, floc}
                    set to_delete to to_delete & pair
                end if
            end try
        end repeat
        repeat with pair in to_delete
            set the_track to item 1 of pair
            set floc to item 2 of pair
            delete the_track
            my delete_the_file(floc)
        end repeat
    end if
end tell

But then I get 'Can't get item 1 of item 1 of selection of application "iTunes".' I think the problem is "this_track" is not an object of class Track, but an item of a selection. How do I get the actual track object from the selection item?

If you don't see the solution, I'll welcome tips on debugging or any other suggestions.

Answer 1

The variable this_track is a reference to an object specifier. You have to use the contents property to get the enclosed object specifier. The same is true for accessing the variable pair in the second loop. See the class reference section on the class reference in the AppleScript language guide.

Another problem exists in the way the list to_delete is being built. The statement set to_delete to to_delete & pair will not produce a list of pairs but a flat list. See the class reference section on the class list in the AppleScript language guide.

Here's a version of your second script, where these bugs have been removed:

tell application "iTunes"
    if selection is not {} then
        set to_delete to {}
        repeat with this_track in selection
            try
                set cla to class of this_track
                set floc to (get location of this_track)
                if cla is file track then
                    set pair to {contents of this_track, floc}
                    copy pair to end of to_delete
                end if
            end try
        end repeat
        repeat with pair in to_delete
            set the_track to item 1 of contents of pair
            set floc to item 2 of contents of pair
            delete the_track
            my delete_the_file(floc)
        end repeat
    end if
end tell