objective-c : Basic delegate pattern

Basic delegate pattern.m

//Basic delegate pattern


//AppDelegate.h

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;

@end


//AppDelegate.m

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    return YES;
}

@end




//AddDelegateViewController.h

@protocol AddDelegateViewControllerDelegate;

@interface AddDelegateViewController : UIViewController

// AddViewControllerDelegate
@property (nonatomic, weak) id <AddDelegateViewControllerDelegate> delegate;

@end


// Protocol definition starts here
@protocol AddDelegateViewControllerDelegate <NSObject>

@required

- (void) addDelegateViewControllerDidSave;
- (void) addDelegateViewControllerDidCancel;

@end
// Protocol Definition ends here




//AddDelegateViewController.m

@implementation AddDelegateViewController

//Cancel
- (IBAction)addViewCancelButtonPressed:(UIBarButtonItem *)sender {
    
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    if (self.delegate && [self.delegate respondsToSelector:@selector(addDelegateViewControllerDidCancel)]) {
        [self.delegate addDelegateViewControllerDidCancel];
    }
}


//Save
- (IBAction)addViewSaveButtonPressed:(UIBarButtonItem *)sender {
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    if (self.delegate && [self.delegate respondsToSelector:@selector(addDelegateViewControllerDidSave)]) {
        [self.delegate addDelegateViewControllerDidSave];
    }
}


@end



//DelegateTableViewController.h

#import "AddDelegateViewController.h" // needed to include the @delegate protocol info

@interface DelegateTableViewController : UITableViewController <AddDelegateViewControllerDelegate>

@property (nonatomic, strong) AddDelegateViewController *AddDelegateViewController;

- (void)addDelegateViewControllerDidCancel;
- (void)addDelegateViewControllerDidSave;

@end



//DelegateTableViewController.m

@implementation DelegateTableViewController

#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    if ([[segue identifier] isEqualToString:@"toAddView"]) {
        
        //ex
        //1. to typical view controller with modal segue
        //AddDelegateViewController *advc = (AddDelegateViewController *)[segue destinationViewController];
        
        //2. embed in navigation controller with modal segue
        UINavigationController *nav = [segue destinationViewController];
    	AddDelegateViewController *advc = (AddDelegateViewController *)[nav topViewController];
    	advc.delegate = self;
    }
}


- (void)addDelegateViewControllerDidCancel
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    [self dismissViewControllerAnimated:YES completion:^{
        NSLog(@"Dismiss Complete!");
    }];
}


- (void)addDelegateViewControllerDidSave
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    [self dismissViewControllerAnimated:YES completion:^{
        NSLog(@"Dismiss Complete!");
    }];
}


#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 5;
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
    // Configure the cell...
    
    return cell;
}


@end