using iOS delegates - ios

Question

im new to iOS and its developing .there i have used iOS delegates to pass values in between view controllers
1. Essentialinfocontroller - its got TableView
2. detailcontroller -
i want to pass values of Essentialinfocontroller to detailcontroller
to do that i used delegates but nothing print on console please help me.
Essentialinfocontroller.h
#import <UIKit/UIKit.h>
#protocol sendTestData <NSObject>
-(void)sendDataToA:(NSArray *)array;
#end
#interface Essentialinfocontroller : UIViewController<UITableViewDataSource,UITableViewDelegate>
#property (weak, nonatomic) IBOutlet UITableView *info;
#property (nonatomic,strong) NSDictionary * courses;
#property (nonatomic, strong)NSArray *coursekeys;
#property(nonatomic,strong) NSString* customeLink;
#property (nonatomic,retain)NSArray * array;
#property(nonatomic,assign)id delegate;
#end
Essentialinfocontroller.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if(indexPath.row==0){
[self giveValuestoNSmutableArray];
[delegate sendDataToA:array];
}
}
-(void)giveValuestoNSmutableArray
{
array = [NSArray arrayWithObjects:#"Jill Valentine", #"Peter Griffin", #"Meg Griffin", #"Jack Lolwut",
#"Mike Roflcoptor", #"Cindy Woods", #"Jessica Windmill", #"Alexander The Great",
#"Sarah Peterson", #"Scott Scottland", #"Geoff Fanta", #"Amanda Pope", #"Michael Meyers",
#"Richard Biggus", #"Montey Python", #"Mike Wut", #"Fake Person", #"Chair",
nil];
}
detailcontroller.h
#import <UIKit/UIKit.h>
#import "Essentialinfocontroller.h"
#interface detailcontroller : UIViewController <sendTestData>
#end
detailcontroller.m
#import "detailcontroller.h"
#interface detailcontroller ()
#end
#implementation detailcontroller
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
Essentialinfocontroller * acontollerobject=[[Essentialinfocontroller alloc] initWithNibName:#"Essentialinfocontroller" bundle:nil];
acontollerobject.delegate=self; // protocol listener
[self.navigationController pushViewController:acontollerobject animated:YES];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)sendDataToA:(NSArray *)array
{
for (NSString *string in array) {
NSLog(#"%#", string);
}
}
#end

Answer 1

You've got the relationship between controllers and delegates a little backwards. A delegate is used to pass information back. Your tableViewController is the detailController's delegate, and detailController shouldn't be allocating an EssentialInfoController inside it. You're basically creating a whole new EssentialInfoController that's different from the first one.
The easiest way to pass data is just to set it when the detailController is allocated. Also, since you're using storyboards, you have to use (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender to allocate the detailController.
Here's what I would do:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if(indexPath.row==0){
[self performSegueWithIdentifier:#"OpenDetailsController"];
}
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
DetailController *controller = (DetailController *)[segue destinationViewController];
NSArray *array = <your array here>;
[controller setArray:array];
}
In your storyboard, set the Storyboard Segue Identifier for that segue to "OpenDetailsController".
A delegate function is defined through a protocol, and you would have the DetailController call its delegate like this:
[self.delegate doSomething];
And in the EssentialInfoViewController you have to define the delegate function
-(void)doSomething {
}