Multiple sharedInstance called failed

Question

In my application i have called sharedinstance multiple time in multiple method deffinition , Here my code,

Method 1

 -(void) showActionSheet:(id)sender forEvent:(UIEvent*)event
 {
  if(isQuantity==YES)
  {
    [[WebService sharedInstance] getQuantity:^(BOOL result)
     {
      if(result)
     {
      NSLog(@"success");
      NSManagedObjectContext *context = [[DataAccessLayer sharedInstance] managedObjectContext];
      Quantity = [context fetchObjectsForEntityName:NSStringFromClass([GetQuantity class]) withSortColumn:nil withSortDescending:TRUE withPredicate:nil];
             NSLog(@"array ->%@",Quantity);
             isQuantity=NO;
         }
     }];
  }

 popoverController1 = [[TSPopoverController alloc]initWithContentViewController:tableViewController1];
 popoverController1.cornerRadius = 5;
 popoverController1.titleText = @"Quantity";
 popoverController1.popoverBaseColor = [UIColor blackColor];
 popoverController1.popoverGradient= NO;
[popoverController1 showPopoverWithTouch:event];
}

Method 2

-(void) showActionSheetw:(id)sender forEvent:(UIEvent*)events  
 {
if(isSize==YES)
{
    [[WebService sharedInstance] getDimension:^(BOOL result)
     {
         if(result){
              NSLog(@"success");
             NSManagedObjectContext *context = [[DataAccessLayer sharedInstance] managedObjectContext];
             dime = [context fetchObjectsForEntityName:NSStringFromClass([Getdimension class]) withSortColumn:nil withSortDescending:FALSE withPredicate:nil];
             NSLog(@"array ->%@",dime);


         }
     }];
}
popoverController2 = [[TSPopoverController alloc] initWithContentViewController:tableViewController2];
popoverController2.cornerRadius = 5;
popoverController2.titleText = @"Size";
popoverController2.popoverBaseColor = [UIColor blackColor];
popoverController2.popoverGradient= NO;
//    popoverController.arrowPosition = TSPopoverArrowPositionHorizontal;
[popoverController2 showPopoverWithTouch:events];
}

EDIT

 - (void) getDimension:(void (^)(BOOL))handler
{
JBContainedURLConnection *connection = [[JBContainedURLConnection alloc]init ];

[connection initWithGETUrl:IP methodName:GETDIMENSION param:nil andCompletionHandler:^(JBContainedURLConnection *connection, NSError *error, NSString *urlString, NSDictionary *userInfo, NSData *response)
 {
     if(error)
     {
         NSLog(@"Error: %@", error);
         handler(FALSE);
     }
     else
     {
         if(response == nil)
             handler(FALSE);
         else
         {
             NSManagedObjectContext *context = [[DataAccessLayer sharedInstance] managedObjectContext];
             NSArray *existingResults = [context fetchObjectsForEntityName:NSStringFromClass([Getdimension class]) withSortColumn:nil withSortDescending:FALSE withPredicate:nil];
             for (NSManagedObject *obj in existingResults)
                 [context deleteObject:obj];
             [[DataAccessLayer sharedInstance] saveContext];
             id responseData = [self DictionaryFromResponse:response];
             if(responseData == nil)
                 handler(FALSE);

             else
             {
                 NSLog(@"Dimension Response: %@", [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding]);
                 NSArray *data=[responseData objectForKey:@"GetDimensionResult"];
                  NSLog(@"GetDimensionResult :%@",data);
                 for( NSDictionary *dict in data){
                     Getdimension *userDetails = [Getdimension newObject];
                     [userDetails fillFromDictionary:dict];

                 }
                 [[DataAccessLayer sharedInstance] saveContext];
                 handler(TRUE);
             }
         }         }
 }];
}


 - (void) getQuantity:(void (^)(BOOL))handler
 {
 JBContainedURLConnection *connection = [[JBContainedURLConnection alloc]init ];

[connection initWithGETUrl:IP methodName:GETQUANTITY param:nil andCompletionHandler:^(JBContainedURLConnection *connection, NSError *error, NSString *urlString, NSDictionary *userInfo, NSData *response)
 {
     if(error)
     {
         NSLog(@"Error: %@", error);
         handler(FALSE);
     }
     else
     {
         if(response == nil)
             handler(FALSE);
         else
         {
             NSManagedObjectContext *context = [[DataAccessLayer sharedInstance] managedObjectContext];
             NSArray *existingResults = [context fetchObjectsForEntityName:NSStringFromClass([GetQuantity class]) withSortColumn:nil withSortDescending:FALSE withPredicate:nil];
             for (NSManagedObject *obj in existingResults)
                 [context deleteObject:obj];
             [[DataAccessLayer sharedInstance] saveContext];
             id responseData = [self DictionaryFromResponse:response];
             if(responseData == nil)
                 handler(FALSE);

             else
             {
                 NSLog(@"GetQuantityResult Response: %@", [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding]);
                 NSArray *data=[responseData objectForKey:@"GetQuantityResult"];
                // NSLog(@"GetDimensionResult :%@",data);
                 for( NSDictionary *dict in data){
                     GetQuantity *userDetails = [GetQuantity newObject];
                     [userDetails fillFromDictionary:dict];

                 }
                 [[DataAccessLayer sharedInstance] saveContext];
                 handler(TRUE);
             }
         }  }
 }];
 }

Instance method

 + (id)sharedInstance
{
@synchronized(self)
{
    if (manager == nil)
        manager = [[self alloc] init];
}
return manager;
}


-(id)init
{
if(self = [super init])
{
}
return self;
}

-(NSString *)NSStringFromDictionaryUsingJSON:(id)dictionary
{
SBJsonWriter *writer = [[SBJsonWriter alloc]init];
return [writer stringWithObject:dictionary];
 }

 -(id)DictionaryFromResponse:(NSData *)response
 {
NSString *responseBody =  [[NSString alloc] initWithData:response encoding:NSASCIIStringEncoding];
SBJsonParser *parser = [[SBJsonParser alloc]init];
return [parser objectWithString:responseBody  error:nil];
}

sharedInstance only works one time,ie,. if i call any of the method first its worked,if calls other method second time app gets crashed.Can any one please help me to sort it out

can you post your code? what you have written sharedInstance method in class webservice — Niru Mukund Shah, May 20 '13 at 09:05
@ForamMukundShah if am calling getDimension it will work, when i call getQuantity next to tat its getting crash.. if am calling getQuantity it will work, when i call getDimension next to tat its getting crash..ie. first called function only worked — Globas techn, May 20 '13 at 09:11
webservice class is having sharedinstance method. I want that only — Niru Mukund Shah, May 20 '13 at 09:14
check my answer given here.And try to run your code by replacing given method — Niru Mukund Shah, May 20 '13 at 09:20
Where have you declared manager? It should be static variable and you need to call sharedInstance everytime you want to get that instance. — Praveen S, May 20 '13 at 09:21

score 0 · Answer 1 · answered May 20 '13 at 09:19

0

I guess sharedInstance method is messy.

It should be

+ (id)sharedInstance
{
    if (manager == nil)
        manager = [[self alloc] init];

return manager;
}

Enjoy Programming !

answered May 20 '13 at 09:19

Niru Mukund Shah

4,637
2
20
34

Now when i call the method first time itself crahsed\ – Globas techn May 20 '13 at 09:23
Nothing is coming in call log. Thats the problem – Globas techn May 20 '13 at 09:36
in `+ (id)sharedInstance` method derived class – Globas techn May 20 '13 at 09:56
i have mentioned the instance method in question, there only i have declared + (id)sharedInstance – Globas techn May 20 '13 at 10:50
I am not able to see static WebService __strong *manager = nil; in sharedinstance method – Niru Mukund Shah May 20 '13 at 10:51
static WebService __strong *manager = nil; is supposed to be declared in .m file before @implementation section – Niru Mukund Shah May 20 '13 at 10:52
Yes its was in .h section only\ – Globas techn May 20 '13 at 11:17
that shows error ` Use of undeclared identifier '_manager'; did you mean 'manager'?` – Globas techn May 20 '13 at 11:24
since it is stated as static WebService __strong *manager = nil; should i want o change into @peoperty static WebService __strong *manager = nil; – Globas techn May 20 '13 at 11:33
without property initialisation how can i sychronise – Globas techn May 20 '13 at 11:46
Property implementation must have its declaration in interface 'WebService' – Globas techn May 20 '13 at 11:54
yes it should have, but from our discussion it seems like everything in the sharedInstance method is working fine. Now I wonder why it is getting called only once? – Niru Mukund Shah May 20 '13 at 11:55

score 0 · Answer 2 · answered May 20 '13 at 09:25

0

Have you declared instance of your class as static, Declare you class object as :

static ClassName *manager;

And the allocate the same object in your sharedInstance method. The reason may be that the memory object was released but reference is still there in the memory.So when you execute the shared instance method it found a reference to !nil object and leads your application to crash.

This is singleton class feature of iOS(objective C)

answered May 20 '13 at 09:25

Deepak Srivastava

178
7

i have declared the `static WebService __strong *manager = nil; ` in webservice class.. should i want to add in method class which i called – Globas techn May 20 '13 at 09:28
No you are not supposed to add this in the calling class. – Deepak Srivastava May 20 '13 at 09:45
@peter What exactly the error is that you are getting in the console.it will be really helpful if you please send me the "error log" – Deepak Srivastava May 20 '13 at 09:49

Multiple sharedInstance called failed

2 Answers2