Ok, I have a NSOutlineView set up, and I want it to capture PDF's if a pdf is dragged into the NSOutlineView.

My first question, I have the following code:

    [outlineView registerForDraggedTypes:[NSArray arrayWithObjects:NSStringPboardType, NSFilenamesPboardType, nil]];

In all the apple Docs and examples I've seen I've also seen something like MySupportedType being an object registered for dragging. What does this mean? Do I change the code to be:

    [outlineView registerForDraggedTypes:[NSArray arrayWithObjects:@"pdf", NSStringPboardType, NSFilenamesPboardType, nil]];

Currently I have it set up to recognize drag and drop, and I can even make it spit out the URL of the dragged file once the drag is accepted, however, this leads me to my second question. I want to keep a copy of those PDF's app side. I suppose, and correct me if I'm wrong, that the best way to do this is to grab the data off the clipboard, save it in some persistant store, and that's that. (as apposed to using some sort of copy command and literally copying the file to the app director.)

That being said, I'm not sure how to do that. I've the code:

- (BOOL)outlineView:(NSOutlineView *)ov acceptDrop:(id <NSDraggingInfo>)info item:(id)item childIndex:(NSInteger)childIndex 
{
    NSPasteboard *pboard = [info draggingPasteboard];
    NSURL *fileURL;
    if ( [[pboard types] containsObject:NSURLPboardType] ) {
        fileURL = [NSURL URLFromPasteboard:pboard];
        // Perform operation using the file’s URL
    }

    NSData *data = [pboard dataForType:@"NSPasteboardTypePDF"];

But this never actually gets any data. Like I said before, it does get the URL, just not the data. Does anyone have any advise on how to get this going? Thanks so much!