ios custom delegate is null after second click in navigation controller - ios

Question

I have a custom UIWebView (EpubWebView), with a custom NSURLCache (EpubCache) for handling requests.
i created a custom delegate for handling request.
EpubCache.h
#protocol EpubCacheDelegate <NSObject>
#required
- (NSCachedURLResponse *)hadleRequest:(NSURLRequest *)request;
#end
#interface EpubCache : NSURLCache
#property (nonatomic, weak) id <EpubCacheDelegate> cacheDelegate;
#end
EpubCache.m
import "EpubCache.h"
#interface EpubCache ()
#end
#implementation EpubCache
- (NSCachedURLResponse *)cachedResponseForRequest:(NSURLRequest *)request
{
return [self.cacheDelegate hadleRequest:request];
}
#end
EpubWebView .h
#interface EpubWebView : UIWebView <UIWebViewDelegate, EpubCacheDelegate>
#property (strong, nonatomic) EpubCache *mLocalCache;
#end
EpubWebView.m
- (void) localInit
{
self.mLocalCache = [[EpubCache alloc] init];
self.mLocalCache.cacheDelegate = self;
[NSURLCache setSharedURLCache:self.mLocalCache];
}
- (NSCachedURLResponse *)hadleRequest:(NSURLRequest *)request
{
// return handled request
}
on the other hand i have a navigationcontroller with a tableview and the destination view controller have this webview.
when i ran the app and click on an item in tableview, everything is fine and delegate works as expected.
if i click back and click on other item in tableview, things goes wrong, the cachedResponseForRequest getting called but the hadleRequest wont, i checked and findout that the delegate is null!
i can not figure out what is happening here.
any help would be appreciated.
UPDATE 1
EpubWebView.m
- (id)init
{
self = [super init];
if (self)
{
[self localInit];
}
return self;
}
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if(self)
{
[self localInit];
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if(self)
{
[self localInit];
}
return self;
}
UPDATE 2
the segue of the tableview that bring up the view controller that contain EpubWebView
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
NSIndexPath *indexPath = [self.collectionView indexPathForCell:sender];
BookViewController *bookController = segue.destinationViewController;
bookController.mBook = booksList[indexPath.row];
}
and BookViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
mWebView = [[EpubWebView alloc] initWithFrame:self.mainView.frame];
[self.mainView addSubView:mWebView];
[mWebView setBook:self.mBook];
}

Answer 1

You need to make a few modifications. First, remove your "localInit" method, then create a new function in EPubWebView:
- (void) setCache: (EpubCache *)localCache
{
localCache.cacheDelegate = self;
}
Now, you can create and hold onto your cache in your BookViewController via these lines in the .m file:
#interface BookViewController ()
#property (strong, nonatomic) EpubCache *mLocalCache;
#end
and change your BookViewController's viewDidLoad method to look like:
- (void) viewDidLoad {
self.mLocalCache = [[EpubCache alloc] init];
// only need to do this once, at viewDidLoad time
[NSURLCache setSharedURLCache:self.mLocalCache ];
[super viewDidLoad];
mWebView = [[EpubWebView alloc] initWithFrame:self.mainView.frame];
[mWebView setCache:self.mLocalCache];
[self.mainView addSubView:mWebView];
[mWebView setBook:self.mBook];
}