Swift - not working correctly IOS 9.2 - ios

Question

I have added a table view, and I am display image in the cells. I have also added this code:
So that the cells resize depending on the image.
When I launch my app though, I get this : [![enter image description here][1]][1]
And the images do not load untill I start scrolling...If I scroll down half the page then go back to the top, I get this: Which is correct
[![enter image description here][2]][2]
Any ideas? I have researched on google and tried the odd solution for the older versions of Xcode, But nothing seems to work!
Here is the rest of my code from the TableViewController:

Answer 1

Image isn't loaded correctly in cellForRowAtIndexPath delegate method, you're (probably) downloading the image in the background, so cellForRowAtIndexPath is returned before image is ready.
Downloaded image is probably cached somewhere so next time it's loaded properly.
post.downloadImage() better have a callback closure to be called when image was downloaded, to assign the downloaded image into the proper cell.
Keep in mind that user may scroll this cell out of the screen before image is loaded, so you better use a unique id to abort downloaded image assignment if cell has already changed.
Here's an example for a method that downloads an image in the background, then assigns it to the cell -
+ (void)loadImage:(NSString *)imageUrl onComplete:(void(^)(UIImage *image, BOOL loaded, NSString *callIdentifier))callback callIdentifier:(NSString *)callIdentifier {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul), ^{
[self downloadPicture:url onComplete:^(UIImage *image, BOOL loaded) {
dispatch_sync(dispatch_get_main_queue(), ^{
callback(image, loaded, callIdentifier);
});
}];
});
callback([UIImage imageNamed:#"placeholder"], NO, callIdentifier);
}
+ (void)downloadPicture:(NSString *)url saveTo:(NSString *)filePath onComplete:(void (^)(UIImage *image, BOOL loaded))onComplete {
NSError *error = nil;
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:url] options:NSDataReadingMappedAlways error:&error];
if (!error) {
UIImage *image = [UIImage imageWithData:data scale:GTUserPictureScale];
if (onComplete)
onComplete(image, YES);
} else {
NSLog(#"Error loading user picture: %#", [error description]);
if (onComplete)
onComplete([UIImage imageNamed:#"missing"], NO);
}
}
- (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)indexPath {
// ...
__weak MyClass *wself = self;
self.imageUrl = #"http://...";
[self loadImage:self.imageUrl onComplete:^(UIImage *image, BOOL loaded, NSString *callIdentifier) {
#synchronized(wself) {
if ([callIdentifier isEqualToString:wself.imageUrl]) {
if (loaded) {
wself.image = image;
}
} else
NSLog(#"Expired load image request for id %#", callIdentifier);
}
} callIdentifier:self.imageUrl];
// ...
}