Passing NSMutableArray from one View Controller to a function in another

Question

I've read up on couple of questions here on SO about passing data between two View Controllers and seen different ways suggested of doing it. My problem is as follows:

I have a view controller (lets call it a "A") that has a searchbar in a toolbar. Nothing else. Then I have another view controller ("B") that is responsible for displaying a popover view when the user presses the search button on the keyboard when searching in the searchbar. This all works. The user enters text, presses the search button, the popover is shown. Great.

Now I have yet to display any search results in the popover tableview and am trying to pass a NSMutableArray to a function in B as an argument:

in B.h:

@property (nonatomic, retain) NSMutableArray *searchResults;

in B.m:

    @synthesize searchResults;

     -(void)setSearchResults:(NSMutableArray *)resultArray{
         [self.searchResults removeAllObjects];
         [self.searchResults addObjectsFromArray:resultArray];
     }

in A.h:

#import "B.h"
@property(nonatomic, retain) B *viewControllerObjectB;

in A.m:

@synthesize viewControllerObjectB;

 //The searchResultsArray is passed on from another function
-(void)communicateWithB:(NSMutableArray *)searchResultsArray{

    //I initialize the viewControllerObjectB in here

    NSMutableArray *temp = [[NSMutableArray alloc] initWithArray:searchResultsArray];
    [viewControllerObjectB setSearchResults:temp];
}

Now this all works except I do not get the content of temp passed on into the function in B.m. I'ts empty (nil). This is my problem.

I'm fairly new to iOS so all help would be appreciated.

EDIT: Forgot to mention that I'm using ARC.

i suggest you when you initalize the object of B view controller pass the result array that time. or you have to reload the tableview data after loading new results by calling [viewControllerObjectB.tableview reloadData] — iNeal
– iNeal, Commented Jun 29, 2012 at 12:14
Just to be clear about what is nil, what do you get from NSLog(@"Temp: %@", temp); in the communicateWithB method? Also, NSLog(@"Result: %@", resultArray); in setSearchResults? (And if "Temp" says it's nil, what about searchResultsArray?) — Phillip Mills
– Phillip Mills, Commented Jun 29, 2012 at 12:14
In searchResultsArray I get an array with 5 objects. In communicateWithB I get an empty array. I'm setting a brakepoint just below the addobjectsFromArray line and printing out the contents. — Hrafn
– Hrafn, Commented Jun 29, 2012 at 12:44

DarthMike · Accepted Answer · 2012-06-29 12:35:32Z

1

You didn't initialize your array (that's why it's nil). So in alloc method you should:

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

     if (self) {
          self.searchResults = [NSMutableArray arrayWithCapacity:10];
     }
}

I also spotted 2 problems in your code:

@synthesize searchResults;

     -(void)setSearchResults:(NSMutableArray *)resultArray{
         //PROPERTY LOGIC IS RETAIN, SO YOU NEED TO RELEASE/RETAIN WHEN YOU OVERRIDE A SETTER
         if (searchResults != resultArray) {
              [searchResults release];
              searchResults = [resultArray retain];
         }
     }


-(void)communicateWithB:(NSMutableArray *)searchResultsArray{

    //I initialize the viewControllerObjectB in here
    //MEM. LEAK ON TEMP
    NSMutableArray *temp = [[[NSMutableArray alloc] initWithArray:searchResultsArray] autorelease];
    [viewControllerObjectB setSearchResults:temp];
}

answered Jun 29, 2012 at 12:35

DarthMike

3,4811 gold badge24 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Hrafn Over a year ago

Sorry, should have added that I'm using ARC so I do not need to designate autorelease nor manually release. searchResults is initialized in viewDidLoad so I don't think that is the problem. Thx though.

DarthMike Over a year ago

You have a commment //I initialize the viewControllerObjectB in here, so can it be that viewDidLoad was not called, so your self.searchResults is nil at this point? You should see if searchResults has any array initialized when putting a breakpoint in your setter

Hrafn Over a year ago

I'm a F-ing idiot. I was assigning the array incorrectly. Should have been doind searchResults = resultArray. Though this was not directly what you said, your answer set me straight.

Collectives™ on Stack Overflow

Passing NSMutableArray from one View Controller to a function in another

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related