Execute a selector within another class - ios

Question

I would like to create a UITableViewController within another controller, as well as pass it a method from that controller. I already read that this can be achieved by using #selector. Now I tried the following:
TimeController.m
- (void)choseTime{
SelectOptionController *selectController = [[SelectOptionController alloc] initWithArray:[Time SQPFetchAll] andSelector:#selector(timeSelected)];
[self.navigationController pushViewController:selectController animated:true];
}
- (void) timeSelected{
NSLog(#"Time selected!");
}
SelectOptionController.h
#interface SelectOptionController : UITableViewController
#property (nonatomic, strong) NSMutableArray *dataset;
#property (nonatomic) SEL selectedMethod;
-(id)initWithArray: (NSMutableArray *) myArray andSelector: (SEL) selectedMethod;
SelectOptionController.m
- (id)initWithArray: (NSMutableArray *) myArray andSelector: (SEL) selectedMethod{
self = [super initWithStyle:UITableViewStyleGrouped];
if(self) {
self.dataset = myArray;
self.selectedMethod = selectedMethod;
}
return self;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[self performSelector:self.selectedMethod];
[self.navigationController popViewControllerAnimated:true];
}
However, when a cell gets selected, the following exception is being thrown:
-[SelectOptionController timeSelected]: unrecognized selector sent to instance 0x1450f140
What am I doing wrong over here? Any help would be highly appreciated.

Answer 1

You are calling timeSelected on self which is actually SelectOptionController, but the timeSelected method exists in the TimeController class.
Assuming you don't want to move timeSelected to SelectOptionController, you need to pass a reference to the TimeController to the new SelectOptionController and call the selector on that. A selector is simply a reference to a method, not the method itself. You will probably want to store it as a weak reference too too.
E.g.
#interface SelectOptionController : UITableViewController
#property (nonatomic, strong) NSMutableArray *dataset;
#property (nonatomic) SEL selectedMethod;
#property (nonatomic, weak) TimeController *timeController;
And
- (id)initWithArray: (NSMutableArray *) myArray andSelector: (SEL) selectedMethod timeController:(TimeController*)timeController {
self = [super initWithStyle:UITableViewStyleGrouped];
if(self) {
self.dataset = myArray;
self.selectedMethod = selectedMethod;
self.timeController = timeController;
}
return self;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[self.timeController performSelector:self.selectedMethod];
[self.navigationController popViewControllerAnimated:true];
}
With all of that said, the above will get your code working but this isn't a particularly good pattern. I would suggest you look into Prototypes and Delegates for implementing this behaviour, or if you want to pass the method itself, do some research on Blocks. But hopefully this helps you better understand how selectors work.