CODEWITHSUNDEEP
iphonedelegates
user704010
user704010

Reputation:

Custom Delegate Issues

my protocol method isn't called ... i'm new in obj-c programming ...

i have a header file for protocol

..........CanUpdateTime.h .....................

#import <Foundation/Foundation.h>

@protocol CanUpdateTime

-(BOOL)canUpdateTime;

@end

..............class interface where i declare my delegate variable and set it's property ..............

#import <UIKit/UIKit.h>
#import "Currency.h"
#import "CanUpdateTime.h"

@protocol CanUpdateTime;
@interface CurrencyViewController : UIViewController <UITableViewDelegate, UITableViewDataSource > {


    Currency *currency;
    UILabel *dayMonthYear;



    id <CanUpdateTime> update;  
}

@property (nonatomic, retain) Currency *currency;
@property (nonatomic, retain) IBOutlet UILabel *dayMonthYear;

@property (nonatomic, assign) id <CanUpdateTime> update;

........ implementation file ..............

-(void)viewDidLoad {

  [[self update]canUpdateTime];
}

..... the class where i placed the definition of delegate method ...

@interface ExchangeRatesProvider : NSObject <NSXMLParserDelegate,CanUpdateTime> {

and so on ...

}

.... implementation file ..................

-(BOOL)canUpdateTime {


  NSLog (@"ok");

        return YES;  
}

but nothing happens ... i tried to pass to de update(delegate) respondsToSelector method but nothing happens ... my delegate method doesnt respond ... any ideas ... ???

p.s. sorry for my english ... thanks for attention ...

Upvotes: 1

Views: 137

Answers (2)

mbritto
mbritto

Reputation: 1117

My best guess is that your update variable has never been filled with an ExchangeRatesProvider instance. At some point in your code and before calling [[self update] canUpdateTime] you need to put an object that conforms to your protocol in the variable.

Looking at your code I think the missing line here is :

ExchangeRatesProvider* provider = [[ExchangeRatesProvider alloc] init];
[[self setUpdate:provider];

These lines can be at the very beginning of viewDidLoad or in the init method. Don't forget to release the provider when you're done with it with a [self setUpdate:nil]

Upvotes: 0

visakh7
visakh7

Reputation: 26400

In ExchangeRatesProvider you should set the delegate for CurrencyViewController as

currencyController.update = self;

where currencyController is an instance of CurrencyViewController

Upvotes: 1

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