When manual reload viewDidLoad how clear memory and using viewDidUnload - iphone

Question

Help find out how to solve the problem using the memory in my application, may have another way to implement my task.
Have the following code:
Constants.h
#import <Foundation/Foundation.h>
extern NSString * const ITEM;
extern NSString * const TITLE;
extern NSString * const IMAGE;
extern NSString * const DESCRIPTION;
extern NSString * const TEXT;
#interface Constants : NSObject
{
}
#end
Constants.m
#import "Constants.h"
#implementation Constants
NSString * const ITEM = #"item";
NSString * const TITLE = #"title";
NSString * const IMAGE = #"image";
NSString * const DESCRIPTION = #"description";
NSString * const TEXT = #"text";
- (void)dealloc
{
[super dealloc];
}
#end
myNews.h
#import <Foundation/Foundation.h>
#interface myNews : NSObject
{
NSString *itemTitle;
NSString *itemImageUrl;
NSString *itemDescription;
NSString *itemText;
}
#property (nonatomic, retain) NSString *itemTitle;
#property (nonatomic, retain) NSString *itemImageUrl;
#property (nonatomic, retain) NSString *itemDescription;
#property (nonatomic, retain) NSString *itemText;
#end
myNews.m
#import "myNews.h"
#implementation myNews
#synthesize itemTitle;
#synthesize itemImageUrl;
#synthesize itemDescription;
#synthesize itemText;
#end
XMLController.h
#import <Foundation/Foundation.h>
#class Constants;
#class myNews;
#interface XMLController : NSObject
{
NSMutableString *currentNodeContent;
NSMutableArray *newsArray;
NSXMLParser *parser;
myNews *currentNew;
}
#property (readonly, retain) NSMutableArray *newsArray;
-(id)loadXMLByURL:(NSString *)urlString;
#end
XMLController.m
#import "XMLController.h"
#import "Constants.h"
#import "myNews.h"
#implementation XMLController
#synthesize newsArray;
-(id)loadXMLByURL:(NSString *)urlString
{
newsArray = [[NSMutableArray alloc] init];
NSURL *url = [NSURL URLWithString: urlString];
parser = [[NSXMLParser alloc] initWithContentsOfURL: url];
[parser setDelegate:(id)self];
[parser parse];
return self;
}
-(void) parser:(NSXMLParser *)parser
didStartElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName
attributes:(NSDictionary *)attributeDict
{
if ([elementName isEqualToString: ITEM])
{
currentNew = [myNews alloc];
currentNodeContent = [[NSMutableArray alloc] init];
}
}
-(void) parser:(NSXMLParser *)parser
didEndElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName
{
if ([elementName isEqualToString: TITLE])
{
currentNew.itemTitle = currentNodeContent;
}
if ([elementName isEqualToString: IMAGE])
{
currentNew.itemImageUrl = currentNodeContent;
}
if ([elementName isEqualToString: DESCRIPTION])
{
currentNew.itemDescription = currentNodeContent;
}
if ([elementName isEqualToString: TEXT])
{
currentNew.itemText = currentNodeContent;
}
if ([elementName isEqualToString: ITEM])
{
[newsArray addObject:currentNew];
[currentNew release];
currentNew = nil;
[currentNodeContent release];
currentNodeContent = nil;
}
}
-(void) parser:(NSXMLParser *)parser
foundCharacters:(NSString *)string
{
currentNodeContent = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
}
#end
myAppDelegate.h
#import <UIKit/UIKit.h>
#import "MainViewController.h"
#import "DetailViewController.h"
#class MainViewController;
#class DetailViewController;
#interface myAppDelegate : NSObject <UIApplicationDelegate>
{
UIWindow *window;
UINavigationController *myNavigationController;
MainViewController *myMainViewController;
DetailViewController *myDetailViewController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet UINavigationController *myNavigationController;
#property (nonatomic, retain) IBOutlet MainViewController *myMainViewController;
#property (nonatomic, retain) IBOutlet DetailViewController *myDetailViewController;
#end
myAppDelegate.m
#import "myAppDelegate.h"
#import "myNews.h"
#import "MainViewController.h"
#import "DetailViewController.h"
#implementation myAppDelegate
#synthesize window;
#synthesize myNavigationController;
#synthesize myMainViewController;
#synthesize myDetailViewController;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[window addSubview:myNavigationController.view];
[window makeKeyAndVisible];
return YES;
}
- (void)dealloc
{
[window release];
[myNavigationController release];
[myMainViewController release];
[myDetailViewController release];
[super dealloc];
}
#end
MainViewController.h
#import <UIKit/UIKit.h>
#import "XMLController.h"
#interface MainViewController : UIViewController
{
XMLController *xmlcont;
UILabel *myTitleLabel;
// declared here some 10 objects
}
#property (nonatomic, retain) UILabel *myTitleLabel;
#end
MainViewController.m
#import "MainViewController.h"
#import "myNews.h"
#implementation MainViewController
#synthesize myTitleLabel;
- (void)completeRefresh
{
[myMainViewController viewDidLoad];
}
- (void)viewDidLoad
{
[super viewDidLoad];
UIButton *myRefreshButton = [[UIButton alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 35.0f, 23.0f)];
[myRefreshButton setImage:[UIImage imageNamed:#"ButtonRefresh.png"] forState:UIControlStateNormal];
[myRefreshButton addTarget:self
action:#selector(completeRefresh)
forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *myRefreshBarButton = [[[UIBarButtonItem alloc] initWithCustomView:myRefreshButton] autorelease];
[self.navigationItem setRightBarButtonItem: myRefreshBarButton];
[myRefreshButton release];
xmlcont = [[XMLController alloc] loadXMLByURL:#"http://link_to_XML_file.xml"];
NSLog(#"array = %#", [xmlcont newsArray]);
for (myNews *oneNew in [xmlcont newsArray]) {
CGRect frameTitleLabel = CGRectMake(0.0f, 200.0f, 320.0f, 60.0f);
myTitleLabel = [[UILabel alloc] initWithFrame:frameTitleLabel];
myTitleLabel.backgroundColor = [UIColor blackColor];
myTitleLabel.text = [myOneNew itemTitle];
myTitleLabel.font = [UIFont fontWithName:#"HelveticaNeue-Bold" size: 17.0];
myTitleLabel.textColor = [UIColor whiteColor];
[self.view addSubview:myTitleLabel];
[myTitleLabel release];
}
}
- (void)viewDidUnload
{
self.myTitleLabel = nil;
[super viewDidUnload];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
- (void)dealloc
{
[myTitleLabel release];
[super dealloc];
}
#end
During the test the application using the Instruments: Activity Monitor shows that when you click refresh and call 'completeRefresh' memory (Real Mem) is not cleared when reload viewDidLoad, and accumulates with every touch and calling 'completeRefresh'
Maybe someone has a possible solution?

Answer 1

To avoid leaking memory you need to release your retained ivars/properties in dealloc. For example:
myNews.m
- (void)dealloc {
// Setting these properties to nil releases them because they're (nonatomic, retain)
self.itemTitle = nil;
self.itemImageUrl = nil;
self.itemDescription = nil;
self.itemText = nil;
[super dealloc];
}
XMLController.m
- (void)dealloc {
self.newsArray = nil;
// These ivars aren't properties so you just have to call release on them
[currentNodeContent release];
[parser release];
[currentNew release];
[super dealloc];
}
etc. Do this for all your classes.