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POHow to solve a delegate that is still nil
 

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    <p>I am concerned with my 4 view controllers. The first one is the CardWalletViewController which is a table view that is populated by Card Objects that the user has created (the card creation is OK so I won't post the code regarding that). Now, given that this table view is already populated with Card Objects, once the user clicks on a cell, another view controller, named CardDetailsViewController will show up. This will display the current points that the Card has and also the perks. Note that the current points is shown through a UILabel and the perks were a table view's cells. This table view's cell values(perks), are statically typed and are coming from a NSDictionary and then stored in an NSArray (for cell's text display purpose). Now, when I click on a perk, the PerksDetailsViewController will show up. This contains UILabels which show the perk's name and the points it requires. Those UILabels values were coming from the former ViewController. Also, PerksDetailsVC has a button named redeem. Upon clicking that I'll proceed to another view controller, BarCodeViewController, which takes care of the computation.</p> <p>Now my concern is on how to pass the selected Card, and also the points that corresponds to a selected perk. I've used delegation to do this but then it seems that my delegation object is not being set.</p> <p>Below is my current code.</p> <p>CardWalletViewController.h</p> <pre><code>#import &lt;UIKit/UIKit.h&gt; #import "Card.h" @class CardWalletViewController; @protocol CardWalletDelegate &lt;NSObject&gt; -(void)cardWalletViewController: (CardWalletViewController *)sender withCurrentCard: (Card *) currentCard; @end @interface CardWalletViewController : UITableViewController @property (nonatomic, strong) NSMutableArray *myWallet; @property (nonatomic, weak) id &lt;CardWalletDelegate&gt; delegate; @end </code></pre> <p>CardWalletViewController.m</p> <pre><code>#import "CardWalletViewController.h" #import "AddCardViewController.h" #import "Card.h" #import "CardDetailsViewController.h" @interface CardWalletViewController () @end @implementation CardWalletViewController @synthesize delegate = _delegate; - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier]; } Card *cardDummy = [self.myWallet objectAtIndex:indexPath.row]; //myWallet is an Array where the table cell's values come from cell.textLabel.text = cardDummy.name; cell.detailTextLabel.text = [NSString stringWithFormat:@"%@", cardDummy.points]; return cell; } - (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { //this method is responsible for showing the details of a selected card CardDetailsViewController *details = [self.storyboard instantiateViewControllerWithIdentifier:@"cardDetails"]; Card *selectedCard = [self.myWallet objectAtIndex:indexPath.row]; // I want this selected card to be accessible until the user clicks another card or during end of program. details.myPoints = [NSString stringWithFormat:@"%@", selectedCard.points]; [self.navigationController pushViewController:details animated:YES]; [self.delegate cardWalletViewController:self withCurrentCard:selectedCard]; //checking purposes if (!self.delegate) { NSLog(@"delegate is nil"); } } </code></pre> <p>CardDetailsViewController.m</p> <pre><code>#import "CardDetailsViewController.h" #import "PerksDetailsViewController.h" #import "Card.h" @interface CardDetailsViewController () @end @implementation CardDetailsViewController @synthesize pointsLabel = _pointsLabel; @synthesize myPoints = _myPoints; @synthesize perks = _perks; @synthesize datasource = _datasource; @synthesize datasourcePoints = _datasourcePoints; -(void)setupArray { self.perks = [[NSMutableDictionary alloc] init]; [self.perks setObject:@"200" forKey:@"10% Discount"]; [self.perks setObject:@"100" forKey:@"250Php Off"]; self.datasource = [self.perks allKeys]; //contains perk's description self.datasourcePoints = [self.perks allValues]; //contains perk's required points } -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 2; } -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (!cell) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier]; } cell.textLabel.text = [self.datasource objectAtIndex:indexPath.row]; cell.detailTextLabel.text = [self.datasourcePoints objectAtIndex:indexPath.row]; return cell; } -(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { PerksDetailsViewController *perksDetails = [self.storyboard instantiateViewControllerWithIdentifier:@"detailsOfMyPerks"]; [self.navigationController pushViewController:perksDetails animated:YES]; perksDetails.perkDetailsLabel.text = [self.datasource objectAtIndex:indexPath.row]; perksDetails.pointsLabel.text = [self.perks objectForKey:perksDetails.perkDetailsLabel.text]; } - (void)viewDidLoad { //show the number of points of the selected Card self.pointsLabel.text = self.myPoints; [self setupArray]; [super viewDidLoad]; } </code></pre> <p>PerksDetailsViewController.m</p> <pre><code>#import "PerksDetailsViewController.h" #import "Card.h" #import "CardWalletViewController.h" #import "BarcodeViewController.h" @interface PerksDetailsViewController () @end @implementation PerksDetailsViewController @synthesize pointsLabel = _pointsLabel; @synthesize perkDetailsLabel = _perkDetailsLabel; @synthesize perkDetailText = _perkDetailText; @synthesize pointsText = _pointsText; @synthesize delegate = _delegate; @synthesize pointsRequired = _pointsRequired; - (IBAction)redeemPressed:(id)sender { // get required points of a perk selected // cast the NSString value to an NSInteger NSNumberFormatter * f = [[NSNumberFormatter alloc] init]; [f setNumberStyle:NSNumberFormatterDecimalStyle]; self.pointsRequired = [f numberFromString: (self.pointsLabel.text)]; NSLog(@"points required by the perk %@", self.pointsRequired); [self.delegate perksDetailsViewController:self didPassRequiredPoints:self.pointsRequired]; if (!self.delegate){ NSLog(@"delegate is nil"); } } </code></pre> <p>PerksDetailsViewController.h</p> <pre><code>#import &lt;UIKit/UIKit.h&gt; #import "BarcodeViewController.h" @class PerksDetailsViewController; @protocol PerksDetailsDelegate &lt;NSObject&gt; - (void)perksDetailsViewController:(PerksDetailsViewController *)sender didPassRequiredPoints: (NSNumber *) requiredPoints; @end @interface PerksDetailsViewController : UIViewController { NSString *perkDetailText; NSString *pointsText; IBOutlet UILabel *perkDetailsLabel; IBOutlet UILabel *pointsLabel; } @property (nonatomic, retain) IBOutlet UILabel *perkDetailsLabel, *pointsLabel; @property (nonatomic, retain) NSString *perkDetailText, *pointsText; @property (nonatomic, weak) NSNumber *pointsRequired; @property (nonatomic, weak) id &lt;PerksDetailsDelegate&gt; delegate; @end </code></pre> <p>Now this ViewController is the one that implements the two delegate methods </p> <p>BarCodeViewController.h</p> <pre><code>#import &lt;UIKit/UIKit.h&gt; @interface BarcodeViewController : UIViewController @property (nonatomic, strong) NSNumber *myPoints; @end </code></pre> <p>BarCodeViewController.m</p> <pre><code> #import "BarcodeViewController.h" #import "CardWalletViewController.h" #import "Card.h" #import "PerksDetailsViewController.h" @interface BarcodeViewController () &lt;CardWalletDelegate, PerksDetailsDelegate&gt; @end @implementation BarcodeViewController @synthesize myPoints = _myPoints; - (void)perksDetailsViewController:(PerksDetailsViewController *)sender didPassRequiredPoints:(NSNumber *)requiredPoints { self.myPoints = requiredPoints; } - (void)cardWalletViewController:(CardWalletViewController *)sender withCurrentCard:(Card *)currentCard { Card *myCurrentCard = currentCard; [myCurrentCard.pointsToDeduct addObject:self.myPoints]; NSLog(@"contents :%@", [myCurrentCard.pointsToDeduct description]); } @end </code></pre>
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    1. COWhere is the code where you set your PerksDetailsViewController's delegate property?
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    2. COWill post them in a while, stay tuned.
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