iOS - Storing groups of UILabels into a NSMutableArray - objective-c

Question

I'm creating UILabels dynamically in a for each loop. Every loop that is run creates 1-4 UILabels.
What I want is that I put these UILabels into my NSMutableArray and being able later to easy retrieve the data.
My original thought was to put these UILabels into a NSDictionary and use [dictGroupLabels setValue:uiLabel1 forKey:#"uiLabel1"] and then [dictGroupLabels setValue:uiLabel2 forKey:#"uiLabel2"] and so on. And then put this dictionary into my NSMutableArray for each loop. Later on I could access the values like UILabel *label = [[myArray objectAtIndex:0] valueForKey:#"uiLabel1"] BUT that unfortunately doesn't work since UILabels don't conform to the NSCopying protocol.
So with this in mind how would you solve this?

Answer 1

this question provided more information on what you are trying to accomplish. Since you know for a fact, the possible set of labels you are trying to create in each case, I would highly recommend using mutable dictionaries instead of arrays.
To illustrate, given the following hypothetical class definition:
#interface MyClass: NSObject {
NSMutableDictionary * _labelDict;
}
#property (nonatomic, retain) NSMutableDictionary * labelDict;
- ( void )methodA;
- ( void )methodB;
- (NSMutableDictionary *) labelsForRunLoop: (NSUInteger) loopIdx;
#end
You would have the following, hypothetical, class implementation:
#implementation MyClass
#synthesize labelDict = _labelDict;
- ( id ) init {
if( ( self = [ super init ] ) ) {
[self setLabelDict: [NSMutableDictionary dictionaryWithCapacity: 8]];
}
}
- ( void ) dealloc {
[ self.labelDict release ];
[ super dealloc ];
}
- ( void ) methodA {
for(NSUInteger i = 0; i < some index; i++) {
[self.labelDict setObject: [self labelsForRunLoop: i] forKey: [NSString stringWithFormat: #"%d", i]];
}
}
- ( void ) methodB {
// Locate the label you need to work with. Example based on this crude pseudo code
NSMutableDictionary * subDict = (NSMutableDictionary *) [self.labelDict objectForKey: #"0"];
UILabel * theLabel = (UILabel * ) [subDict objectForKey: #"UILabel.Z"];
theLabel.text = #"Label 1";
}
- (NSMutableDictionary *) labelsForRunLoop: (NSUInteger) loopIdx {
NSMutableDictionary * dictionary = [NSMutableDictionary dictionaryWithCapacity: 4] ;
[dictionary setObject: create-w-label forKey: #"UILabel.W"];
[dictionary setObject: create-x-label forKey: #"UILabel.X"];
[dictionary setObject: create-y-label forKey: #"UILabel.Y"];
[dictionary setObject: create-z-label forKey: #"UILabel.Z"];
return [dictionary retain];
}
#end
This is basically pseudo code and will not successfully compile. However it will serve as a good starting point. You probably want to store each label dictionary under some key that makes sense, instead of just using the loop's index. Hope this helps.

Answer 2

They don’t need to adhere to NSCopying to be added to an array. It sounds like you just need to do something like this:
NSMutableArray *mainArray = [NSMutableArray array];
for(int i = 0; i < 5; i++)
{
NSMutableArray *subArray = [[NSMutableArray alloc] initWithCapacity:5];
for(int j = 0; j < 4; j++)
{
UILabel *label = [[UILabel alloc] init];
// etc.
[subArray addObject:label];
[label release];
}
[mainArray addObject:subArray];
[subArray release];
}
// then, to get one of the labels:
UILabel *someSpecificLabel = [[mainArray objectAtIndex:2] objectAtIndex:1];