Converting JSON From AFNetworking - ios

Question

I am using AFNetworking to obtain JSON from a URL, the JSON is parsed and is supposed to be converted into an NSData format which is then in turn put into an array. However it doesn't seem to be working. I think i'm being stupid because it worked previously but now-
-(void)loadFromServer{
NSString *trendsURL = [NSString stringWithFormat:#"http://myurl.com/data.json"];
NSURL *url = [NSURL URLWithString:trendsURL];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFJSONRequestOperation *operation = [AFJSONRequestOperation
JSONRequestOperationWithRequest:request
success:^(NSURLRequest *request, NSHTTPURLResponse *response, id json) {
self.results = [json valueForKeyPath:#"data"];
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
}];
[operation start];
NSError *anError = nil;
NSArray *parsedElements = [NSJSONSerialization JSONObjectWithData:elementsData
options:NSJSONReadingAllowFragments
error:&anError];
for (NSDictionary *aModuleDict in parsedElements){
MosData *aMosModule = [[MosData alloc] initWithDictionary:aModuleDict];
[elements addObject:aMosModule];
}
}
The data is displayed in a collection like view separately, there is no problem with this separate view as it works when I access data from a file rather than server.
-(void)loadFromDisk{
NSString *pathString = [[NSBundle mainBundle] pathForResource:#"data" ofType:#"json"];
NSData *elementsData = [NSData dataWithContentsOfFile:pathString];
NSError *anError = nil;
NSArray *parsedElements = [NSJSONSerialization JSONObjectWithData:elementsData
options:NSJSONReadingAllowFragments
error:&anError];
for (NSDictionary *aModuleDict in parsedElements){
MosData *aMosModule = [[MosData alloc] initWithDictionary:aModuleDict];
[elements addObject:aMosModule];
}
}
The JSON that is fetched is like so:
{
"imageLink": "http://link.com/image.jpg",
"size": 1,
"title": "Food"
}
I gave it another go, and still it's not working. results is a declared NSArray.
-(void)loadFromServer{
NSString *trendsURL = [NSString stringWithFormat:#"http://url.com/data.json"];
NSURL *url = [NSURL URLWithString:trendsURL];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFJSONRequestOperation *operation = [AFJSONRequestOperation
JSONRequestOperationWithRequest:request
success:^(NSURLRequest *request, NSHTTPURLResponse *response, id json) {
NSLog(#"Custom Mosaic: %#", json);
self.results = [json valueForKeyPath:#"data"];
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
}];
[operation start];
for (NSDictionary *aModuleDict in self.results){
MosData *aMosModule = [[MosData alloc] initWithDictionary:aModuleDict];
[elements addObject:aMosModule];
}
}
I think the issue might actually be this having played around a little, for some reason, it won't pick up the results of the data parsed in the AFNetworking operation.
-(id)init{
self = [super init];
if (self){
elements = [[NSMutableArray alloc] init];
[self loadFromServer];
}
return self;
}
// WWDC 2012 proposed method
+ (CustomMosDatasource *)sharedInstance {
static CustomMosDatasource *sharedInstance;
if (sharedInstance == nil)
sharedInstance = [CustomMosDatasource new];
return sharedInstance;
}
#pragma mark - MosViewDatasourceProtocol
-(NSArray *)mosElements{
NSArray *retVal = elements;
return retVal;
}
The results of the log is just JSON:
Custom Mosaic: {
data = (
{
imageFilename = "http://distilleryimage6.instagram.com/9969123a6af311e2b6c722000a9d0edd_7.jpg";
size = 1;
title = "Title";
},

Answer 1

AFJSONRequestOperation *operation = [AFJSONRequestOperation
JSONRequestOperationWithRequest:request
success:^(NSURLRequest *request, NSHTTPURLResponse *response, id json) {
self.results = [json valueForKeyPath:#"data"];
NSError *anError = nil;
NSArray *parsedElements = [NSJSONSerialization JSONObjectWithData:elementsData
options:NSJSONReadingAllowFragments
error:&anError];
for (NSDictionary *aModuleDict in parsedElements){
MosData *aMosModule = [[MosData alloc] initWithDictionary:aModuleDict];
[elements addObject:aMosModule];
}
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
}];
[operation start];

Answer 2

Your json don't seem to have keyPath "data", remove the valueForKeyPath:#"data", please paste the result of "NSLog(#"Custom Mosaic: %#", json)" in your question.
The operation is asynchronized. The success block is called after the request returns data. Please put code in the success block like this
-(void)loadFromServer{
NSString *trendsURL = [NSString stringWithFormat:#"http://url.com/data.json"];
NSURL *url = [NSURL URLWithString:trendsURL];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFJSONRequestOperation *operation = [AFJSONRequestOperation
JSONRequestOperationWithRequest:request
success:^(NSURLRequest *request, NSHTTPURLResponse *response, id json) {
NSLog(#"Custom Mosaic: %#", json);
// your json doesn't have keyPath "data"
self.results = json;
// Codes moved into success block
for (NSDictionary *aModuleDict in self.results){
MosData *aMosModule = [[MosData alloc] initWithDictionary:aModuleDict];
[elements addObject:aMosModule];
}
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
}];
[operation start];
}