macOS Setting the identifier of each column in an NSTableView.

#import <Foundation/Foundation.h>


@interface Person : NSObject {
	NSString *personName;
	float expectedRaise;
}

@property (readwrite, copy) NSString *personName;
@property (readwrite) float expectedRaise;

@end

@implementation Person

@synthesize personName;
@synthesize expectedRaise;

-(id)init
{
	[super init];
	expectedRaise = 5.0;
	personName = @"New Person";
	return self;
}

-(void)dealloc
{
	[personName release];
	[super dealloc];
}

-(void)setNilValueForKey:(NSString *)key
{
	if ([key isEqual:@"expectedRaise"])
	{
		[self setExpectedRaise:0.0];
	}
	else
	{
		[super setNilValueForKey:key];
	}
}

@end

#import <Cocoa/Cocoa.h>
@class Person;

@interface MyDocument : NSDocument
{
	NSMutableArray *employees;
	IBOutlet NSTableView *tableView;
}

-(IBAction)createEmployee:(id)sender;
-(IBAction)removeEmployee:(id)sender;

@end

#import "MyDocument.h"

@implementation MyDocument

- (id)init
{
    self = [super init];
    if (self) 
	{
		employees = [[NSMutableArray alloc] init];
    }
    return self;
}

-(void)dealloc
{
	[employees release];
	[super dealloc];
}

-(IBAction)createEmployee:(id)sender
{
	Person *newEmployee = [[Person alloc] init];
	
	[employees addObject:newEmployee];
	[newEmployee release];
	[tableView reloadData];	
}

-(IBAction)removeEmployee:(id)sender
{
	NSIndexSet *rows = [tableView selectedRowIndexes];
	
	if ([rows count] == 0)
	{
		NSBeep();
		return;
	}
	
	[employees removeObjectsAtIndexes:rows];
	[tableView reloadData];
}

-(int)numberOfRowsInTableView:(NSTableView *)aTableView
{
	return [employees count];
}

-(id)tableView:(NSTableView *)aTableView
	objectValueForTableColumn:(NSTableColumn *)aTableColumn
		   row:(int)rowIndex
{
	NSString *identifier = [aTableColumn identifier];
	
	Person *person = [employees objectAtIndex:rowIndex];
	
	return [person valueForKey:identifier];
}

-(void)tableView:(NSTableView *)aTableView
  setObjectValue:(id)anObject
  forTableColumn:(NSTableColumn *)aTableColumn
			 row:(int)rowIndex
{
	NSString *identifier = [aTableColumn identifier];
	Person *person = [employees objectAtIndex:rowIndex];
	[person setValue:anObject forKey:identifier];
}

- (NSString *)windowNibName
{
    //System Generated code here that I haven't touched but removed from example for readability
}

- (void)windowControllerDidLoadNib:(NSWindowController *) aController
{
    //System Generated code here that I haven't touched but removed from example for readability
}

- (NSData *)dataOfType:(NSString *)typeName error:(NSError **)outError
{
    //System Generated code here that I haven't touched but removed from example for readability
}

- (BOOL)readFromData:(NSData *)data ofType:(NSString *)typeName error:(NSError **)outError
{
    //System Generated code here that I haven't touched but removed from example for readability
}

@end