For a Cocoa project I have this table view controller:
@interface TableViewController : NSObject <NSTableViewDataSource, NSTableViewDelegate>
@property (nonatomic, strong) NSMutableArray *numbers;
@property (nonatomic, strong) NSMutableArray *letters;
@end
#import "TableViewController.h"
@implementation TableViewController
- (NSMutableArray *)numbers
{
if (!_numbers)
{
_numbers = [NSMutableArray arrayWithArray:@[@"1", @"2", @"3", @"4", @"5", @"6", @"7", @"8", @"9", @"10"]];
}
return _numbers;
}
- (NSMutableArray *)letters
{
if (!_letters)
{
_letters = [NSMutableArray arrayWithArray: @[@"a", @"b", @"c", @"d", @"e", @"f", @"g", @"h", @"i", @"j"]];
}
return _letters;
}
// NSTableViewDataSource Protocol Method
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView
{
return self.numbers.count;
}
// NSTableViewDelegate Protocol Method
-(NSView *)tableView:(NSTableView *)tableView viewForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row
{
NSString *identifier = tableColumn.identifier;
NSTableCellView *cell = [tableView makeViewWithIdentifier:identifier owner:self];
if ([identifier isEqualToString:@"numbers"])
{
cell.textField.stringValue = [self.numbers objectAtIndex:row];
}
else
{
cell.textField.stringValue = [self.letters objectAtIndex:row];
}
return cell;
}
In the storyboard I created a NSTableView and set up the connection, after running it I get what I expected:
okay, cool, but I have a question:
why is this working even though I haven't created a NSTableView as a property for my ViewController or for my TableViewController?
Also, there's another problem, now I want to add a button to this window such that, every time I click it, a new item should be added to this table(for now it can be anything)
So I created a button and a method for this and linked the action to the story board:
-(IBAction) addNewNumber:(id)sender
{
[_numbers addObject:@"1234"];
[_letters addObject:@"testing"];
}
Now, every time I click this button I can see that this method is indeed being called and that indeed IT IS adding a new member to these arrays, the thing is, the table is not being updated, what gives? Any advice on how I can fix this behavior?
Updating the arrays won't cause the table view to automatically update as well. You need to tell the table view. Use the following methods:
// Inserts a new rows located at the final positions passed to by 'indexes'. This is similar to NSMutableArray's -insertObjects:atIndexes: The -numberOfRows in the TableView will automatically be increased by the count in 'indexes'. Calling this method multiple times within the same beginUpdates/endUpdates block is allowed, and changes are processed incrementally. This method should not be called for NSOutlineView (use -insertItemsAtIndexes:inParent:withAnimation: instead). The "Cell Based TableView" must first call -beginUpdates before calling this method. This method can also be used when "usesStaticContents=YES".
- (void)insertRowsAtIndexes:(NSIndexSet *)indexes withAnimation:(NSTableViewAnimationOptions)animationOptions API_AVAILABLE(macos(10.7));
/* Removes a row currently at each row in 'indexes'. This is similar to NSMutableArray's -removeObjectsAtIndexes:. The row indexes should be with respect to the current state displayed in the TableView, and not the final state (since the rows do not exist in the final state). The -numberOfRows in the TableView will automatically be decreased by the count in 'indexes'. Calling this method multiple times within the same beginUpdates/endUpdates block is allowed, and changes are processed incrementally. This method should not be called for NSOutlineView (use -removeItemsAtIndexes:inParent:withAnimation: instead). The "Cell Based TableView" must first call -beginUpdates before calling this method. This method can also be used when "usesStaticContents=YES".
*/
- (void)removeRowsAtIndexes:(NSIndexSet *)indexes withAnimation:(NSTableViewAnimationOptions)animationOptions API_AVAILABLE(macos(10.7));
/* Moves a row from the prior 'oldIndex' to 'newIndex' in an animated fashion (if needed). This is similar to removing a row at 'oldIndex' and inserting it back at 'newIndex', except the same view is used and simply has its position updated to the new location. This method can be called multiple times within the same beginUpdates/endUpdates block. This method should not be called for NSOutlineView (use -moveItemAtIndex:inParent:toIndex:inParent: instead). The "Cell Based TableView" must first call -beginUpdates before calling this method. This method can also be used when "usesStaticContents=YES".
*/
- (void)moveRowAtIndex:(NSInteger)oldIndex toIndex:(NSInteger)newIndex API_AVAILABLE(macos(10.7));
/* View Based TableView: API to hide and unhide rows. Sometimes, it is better or easier to simply hide a row instead of permanently removing it from the table. Hiding it allows the model to not change, but the UI to appear as though it doesn't exist. Hidden rows will have a zero height, and not be selectable by the user (but can still be programmatically selected). Be aware that hiding a selected row will leave it selected. Hiding a row will call the delegate methods tableView:didRemoveRowView:forRow:, and unhiding will subsequently call tableView:didAddRowView:forRow:.
*/
- (void)hideRowsAtIndexes:(NSIndexSet *)indexes withAnimation:(NSTableViewAnimationOptions)rowAnimation API_AVAILABLE(macos(10.11));
- (void)unhideRowsAtIndexes:(NSIndexSet *)indexes withAnimation:(NSTableViewAnimationOptions)rowAnimation API_AVAILABLE(macos(10.11));
And there is also -reloadData https://developer.apple.com/documentation/appkit/nstableview/1528382-reloaddata?language=objc
and
-reloadDataForRowIndexes:columnIndexes: https://developer.apple.com/documentation/appkit/nstableview/1527621-reloaddataforrowindexes?language=objc
