How to create block with patameters? ios7 [closed] - ios

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I create block like this:
1) Define your own completion block,
typedef void(^myCompletion)(BOOL);
2) Create a method which takes your completion block as a parameter,
-(void) myMethod:(myCompletion) compblock{
//do stuff
compblock(YES);
}
3)This is how you use it,
[self myMethod:^(BOOL finished) {
if(finished){
NSLog(#"success");
}
}];
How can I send array in block and then get new array from block?
//here I get array of image id's and go in loop for download it all,
NSString *URLString = [NSString stringWithFormat: #"%#", requestString];
NSURL * url = [NSURL URLWithString:URLString];
NSURLRequest * urlRequest = [NSURLRequest requestWithURL:url];
AFHTTPRequestOperation *requestOperation = [[AFHTTPRequestOperation alloc] initWithRequest:urlRequest];
requestOperation.responseSerializer = [AFImageResponseSerializer serializer];
[requestOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
userWithImage = [responseObject copy];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Image error: %#", error);
}];
[requestOperation start];
//here I save it to mutable array and send as completion block,
yep, I think it will be better to send 1 image id and return in block 1 image. And in method there I will call the block - make action with photo separately. so, Is it possible to do?
I can do something like this with NSNotifications, but it will be more widely when it can be in blocks..

Answer 1

1) Define your own completion block
typedef void(^myCompletion)(BOOL finished, NSArray *myArray);
2) Create a method which takes your completion block as a parameter,
-(void)myMethod:(myCompletion)compblock {
//do stuff
NSArray *myArray = ...;
compblock(YES, myArray);
}
3)This is how you use it,
[self myMethod:^(BOOL finished, NSArray *myArray) {
if (finished){
NSLog(#"success");
}
}];

Answer 2

If you just want to write a wrapper around the AFNetworking request you could write a method like this:
- (void)downloadImageWithPath:(NSString *)path completion:(void (^)(AFHTTPRequestOperation *operation, UIImage *image, NSError *error))completion __attribute__((nonnull(2)));
{
NSParameterAssert(completion);
NSURL *url = [NSURL URLWithString:path];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
AFHTTPRequestOperation *requestOperation = [[AFHTTPRequestOperation alloc] initWithRequest:urlRequest];
requestOperation.responseSerializer = [AFImageResponseSerializer serializer];
[requestOperation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
completion(operation, responseObject, nil);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
completion(operation, nil, error);
}];
[requestOperation start];
}
You would invoke this with something like:
[self downloadImageWithPath:#"http://url/to/image.jpg"
completion:^(AFHTTPRequestOperation *operation, UIImage *image, NSError *error) {
if (error) {
// handle error
return;
}
dispatch_async(dispatch_get_main_queue(), ^{
// Update UI with image
});
}];