How to prefetch images the first time?

[houmie]

SDWebImage does already something like that:

[[SDWebImagePrefetcher sharedImagePrefetcher] prefetchURLs:<NArray with image URLs>];

Is there something like this in Haneke?

[DiAvisoo]

Not sure if this is the best way to go about this, but I solved it by creating a preload method that basically just loads the image to a dummy UIImageView. Works like a charm.

( I believe you need to use the same HNKCacheFormat when you load it for real. )

+ (void)preloadImage:(NSString *)imagePath
{
    NSLog(@"Pre-loading image %@", imagePath.lastPathComponent);

    UIImageView *imageView = [[UIImageView alloc] init];
    HNKCacheFormat *format = [HNKCache sharedCache].formats[@"cacheImageFormat"];
    if (!format)
    {
        format = [[HNKCacheFormat alloc] initWithName:@"cacheImageFormat"];
        format.size = CGSizeMake(1024, 768);
        format.scaleMode = HNKScaleModeNone;
        format.compressionQuality = 1;
        format.diskCapacity = 10000 * 1024 * 1024;
        format.preloadPolicy = HNKPreloadPolicyAll;
    }
    [imageView setHnk_cacheFormat:format];

    if([[NSFileManager defaultManager] fileExistsAtPath:imagePath]) {
        [imageView hnk_setImageFromFile:imagePath];
    }
}

[houmie]

Thank you for your reply. Your post was very inspiring and I did exactly what you suggested.
Unfortunately it doesnt work very reliable. If I disconnect Internet, hoping that those images should be cached and retrieved without internet connection, some of them don't show up and show the placeholder image instead.

[DiAvisoo]

I used this way to make sure a rather big local image would get loaded on the next UIViewController immediately rather than have a slight (but annoying) delay once the UIViewController appeared. Didn't try it for remote images though, too bad it didn't work :(

[houmie]

I take it back. It works!!!

The mistake I made was, setting the cache too small.

format.diskCapacity = 1 * 1024 * 1024;

It simply ran out of cache space, hence it acted unreliably. I think I need to play with it and find a sensible number.

Thank you so much for your help!!

[DiAvisoo]

Alright! Glad I could help :)

[cameronehrlich]

Is this really the best/proper way to do this?
I feel like there should be a more elegant solution...