Add object to NSMUtable Array Singleton - ios

Question

I have a shared singleton classNSMutableArray [ICGlobals sharedApplianceCount](first time using this pattern so bear with me if ive done something really silly here)
.h
#import <Foundation/Foundation.h>
#interface ICGlobals : NSObject
{
NSMutableArray* applianceCount;
}
#property (nonatomic, retain) NSString *applianceCount;
+ (ICGlobals *)sharedApplianceCount;
#end
.m
#import "ICGlobals.h"
#implementation ICGlobals
static ICGlobals *sharedApplianceCount = nil;
+ (ICGlobals *)sharedUser {
if(sharedApplianceCount == nil){
sharedApplianceCount = [[super allocWithZone:NULL] init];
}
return sharedApplianceCount;
}
+ (id)allocWithZone:(NSZone *)zone {
return [self sharedApplianceCount];
}
- (id)copyWithZone:(NSZone *)zone {
return self;
}
#end
In "another view controller" im trying to add the row count of my table view (changeable amount of rows) = self.circuits.count
Having tried this
[[ICGlobals sharedApplianceCount] addObject: self.circuits.count,nil]];
and
[[ICGlobals sharedApplianceCount] = [[NSMutableArray alloc] init];
[[ICGlobals sharedApplianceCount] addObject: self.circuits.count,Nil]];
I get no visible #interface error saying my singleton class declares the selector
same with
NSNumber* numberOfRows = [NSNumber numberWithInteger:self.circuits.count];
[[ICGlobals sharedApplianceCount]addObject:[NSMutableArray arrayWithObjects:numberOfRows, nil]];
and with
[ICGlobals sharedApplianceCount] = self.circuits.count;
I get expression assignable. Singleton class has been imported.

Answer 1

You have an inconsistency in your interface declaration. You declare ivar of type NSMutableArray and then a NSString property. Firstable, you don't need to declare ivar, declaring a property does it for you. So your interface should look like:
#interface ICGlobals : NSObject
#property (nonatomic, retain) NSMutableArray *applianceCount;
+ (ICGlobals *)sharedApplianceCount;
#end
Furthermore, you have a naming glitch. You should not use name applianceCount for an array. In general, naming convention of Cocoa suggests that count should be a number (int or NSUInteger). I would change this property name to applianceCounts.
Then, when you initialize your singletone, you can also initialize the array:
+ (ICGlobals *)sharedUser
{
if(sharedApplianceCount == nil)
{
sharedApplianceCount = [[super allocWithZone:NULL] init];
sharedApplianceCount.applianceCounts = [[NSMutableArray alloc] init];
}
return sharedApplianceCount;
}
Finally, here is how to add data to your singletone's applianceCounts array from view controller.
NSNumber* numberOfRows = [NSNumber numberWithInteger:self.circuits.count];
[[ICGlobals sharedApplianceCount].applianceCounts addObject:numberOfRows];
This should point you to right direction.
I don't fully get what you are trying to achieve like I don't understand why you want to have an array there, so if you need further help please let me know in the comments.
I fully recommend you reading about naming conventions. A good start is this article:
Introduction to Coding Guidelines for Cocoa.

Answer 2

I would recommend some refactoring to your class.
First you make the interface like this:
#interface ICGlobals : NSObject
// add the app count but make it private, because you will provide methods to access it
#property (nonatomic, readonly) NSString *applianceCount;
// return ICGlobals instance
+ (ICGlobals)sharedCounter;
- (NSInteger)count;
- (void)addObject:(id)object;
now in .m file
#implementation ICGlobals
static ICGlobals *sharedApplianceCount = nil;
// this is your method, just changed the name
+ (ICGlobals *)sharedCounter {
if(sharedApplianceCount == nil){
sharedApplianceCount = [[super allocWithZone:NULL] init];
}
return sharedApplianceCount;
}
// instance methods goes here
- (NSInteger)count
{
return _applicationCount.count;
}
- (void)addObject:(id)object
{
[_applicationCount addObject:object];
}
Now call [[ICGlobals sharedCount]addObject:object] from any viewController