![\"Screen](\"http:\/\/www.corbinstreehouse.com\/blog\/wp-content\/uploads\/2014\/04\/Screen-Shot-2014-04-26-at-8.52.47-PM.png\")
<\/p>\nSometimes you may find your application has rather complex rows, and you want an NSViewController to manage each row in a “View Based” NSTableView. This is fairly easy to do, and I did it in my Cyr Wheel pattern editing application. My “Cell View” that I want for each row was designed in Xcode like:<\/p>\n
<\/p>\n
A simple NSViewController subclass:<\/p>\n
<\/p>\n
@interface<\/span> CDPatternItemViewController : NSViewController\r\n \/\/ the thing we are editing<\/span>\r\n @property<\/span>(weak) CDPatternItem *patternItem;\r\n@end<\/span>\r\n<\/pre>\n<\/div>\n\nThe controller code is what is interesting. I use an NSWindowController subclass, and keep an array of the view controllers:<\/p>\n
\n<\/p>\n
\n\r\n@interface<\/span> CDPatternEditorWindowController () {\r\n@private<\/span>\r\n NSMutableArray *_patternViewControllers;\r\n<\/pre>\n\r\n
\r\n<\/pre>\n\r\n<\/pre>\n\r\nI decided to lazily load the view controllers. On initialization\/load of my window I fill the array with NULL:<\/span><\/font>\r\n<\/pre>\n\r\n
<\/font>\r\n<\/pre>\n<\/div>\n<\/p>\n
\n\r\n-<\/span> (void<\/span>)_resetPatternViewControllers {\r\n _patternViewControllers = NSMutableArray.new;\r\n for<\/span> (NSInteger i = 0<\/span>; i < self._patternSequence.children.count; i++) {\r\n [_patternViewControllers addObject:[NSNull null]]; \/\/ placeholder<\/span>\r\n }\r\n [_tableView reloadData];\r\n}\r\n<\/pre>\n\r\n
\r\n<\/pre>\n\r\n<\/pre>\n\r\n<\/pre>\n\r\n_patternSequence is simply a wrapper around my model object, stored in my Core Data backed NSDocument; it has an array of things I want to show in the table<\/span><\/font>\r\n<\/pre>\n\r\n<\/pre>\n<\/div>\n<\/p>\n
\n\r\n-<\/span> (CDPatternSequence *)_patternSequence {\r\n return<\/span> self.document.patternSequence;\r\n}\r\n<\/pre>\n\r\n
\r\n<\/pre>\n\r\n<\/pre>\n\r\nThen, the view based tableview method that requests the view simply creates and caches it:<\/span><\/font>\r\n<\/pre>\n\r\n<\/pre>\n\r\n<\/pre>\n<\/div>\n<\/p>\n
\n-<\/span> (CDPatternItemViewController *)_patternViewControllerAtIndex:(NSInteger)index {\r\n id<\/span> currentObject = [_patternViewControllers objectAtIndex:index];\r\n CDPatternItemViewController *result;\r\n if<\/span> (currentObject == [NSNull null]) {\r\n CDPatternItem *item = [self._patternSequence.children objectAtIndex:index];\r\n result = [CDPatternItemViewController new];\r\n result.patternItem = item;\r\n [_patternViewControllers replaceObjectAtIndex:index withObject:result];\r\n } else<\/span> {\r\n result = (CDPatternItemViewController *)currentObject;\r\n }\r\n return<\/span> result;\r\n}\r\n\r\n-<\/span> (NSView *)tableView:(NSTableView *)tableView viewForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row {\r\n CDPatternItemViewController *vc = [self _patternViewControllerAtIndex:row];\r\n \/\/ don't set the identifier so it isn't reused...<\/span>\r\n return<\/span> vc.view;\r\n}\r\n<\/pre>\n<\/div>\n\r\n
\r\n<\/pre>\n\r\n
\r\n<\/pre>\n\r\n<\/pre>\n\r\nThis should be fairly straightforward, and easy to read. But if you have questions let me know and I will clarify.<\/span><\/font>\r\n<\/pre>\n\r\n
<\/font>\r\n<\/pre>\n\r\nI <\/span>don't<\/b> cleanup the view controllers when the items are removed from the table. I could use the NSTableView delegate method tableView:didRemoveRowView:forRow: to drop my NSViewController cache at this time if I so wanted. However, my table is small..and I don't bother with this.<\/span><\/font>\r\n<\/pre>\n\r\n
<\/font>\r\n<\/pre>\n\r\n
<\/font>\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"