Can't retrieve the objects from a JSON steam to enumerate

Question

I'm trying to get a grasp on how to use block in Objective C. In this simple app I'm writing, I'm getting a set of images as a JSON stream. I'm trying to get the images out and objectify them and then collect them into a NSMutableArray. Below is my code

WebImage.h

#import <Foundation/Foundation.h>

@interface WebImage : NSObject <NSCopying>

@property (strong, nonatomic) NSString *imageId;
@property (strong, nonatomic) NSString *imageName;
@property (strong, nonatomic) NSString *imagePath;

- (id)initWithId:(NSString *)imageId andName:(NSString *)imageName andPath:(NSString *)imagePath;
+ (NSArray *)retrieveAllImages;

@end

WebImage.m

#import "WebImage.h"
#import "AFNetworking.h"

#define HOST_URL @"http://toonmoodz.osmium.lk/"

@implementation WebImage

#pragma mark - NSCopying
- (id)copyWithZone:(NSZone *)zone
{
    WebImage *newImage = [WebImage new];
    newImage.imageId = self.imageId;
    newImage.imageName = self.imageName;
    newImage.imagePath = self.imagePath;

    return newImage;
}

- (id)initWithId:(NSString *)imageId andName:(NSString *)imageName andPath:(NSString *)imagePath
{
    if (self = [self init]) {
        self.imageId = imageId;
        self.imageName = imageName;
        self.imagePath = imagePath;
    }
    return self;
}

+ (NSArray *)retrieveAllImages  
{
    NSMutableArray *images = [[NSMutableArray alloc] init];

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    [manager GET:[NSString stringWithFormat:@"%@%@", HOST_URL, @"All_Images.php"] parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {

        NSDictionary *dict = responseObject[@"Images"];
        NSArray *arr = [dict allValues];
        [arr enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            NSDictionary *image = obj;
            NSLog(@"%@", image);
            [images addObject:[[WebImage alloc] initWithId:[image objectForKey:@"id"]
                                                         andName:[image objectForKey:@"name"]
                                                         andPath:[image objectForKey:@"image"]]];
        }];

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error in image retrieveing: %@", error.localizedDescription);
    }];

    return [images copy];
}

The incoming JSON stream looks like this

{
    Images =  (
        {
            createddate = "2014-01-08 12:20:24";
            id = 1;
            image = "images/Rock_1.png";
            isEnabled = 1;
            name = "Rock_1";
        },
        {
            createddate = "2014-01-08 15:12:26";
            id = 2;
            image = "images/Rock_2.png";
            isEnabled = 1;
            name = "Rock_2";
        }
    );
}

My problem is I can't retrieve the image objects from the JSON string. When I debug, the compiler doesn't even go into the GET block in the retrieveAllImages method but jumps straight to the return statement.

Can anyone please tell me how to correct this?

I've created a project demonstrating the problem I'm facing and I've uploaded it here if you wanna take a quick look.

Thank you.

Did you try setting a breakpoint **inside** the `GET` block? I think the debugger skips over blocks if you approach them from the outside. — hgwhittle, Jan 14 '14 at 16:30
The only other thing I can think of right now is your `manager` object may be nil? — hgwhittle, Jan 14 '14 at 16:43
Just checked that too and its not nil. This really is a weird scenario. :/ — Isuru, Jan 14 '14 at 16:50
This is not a valid json - check for examples [here](http://json.org/example.html) — Rok Jarc, Jan 14 '14 at 17:06
The above dump is actually a dump of an NSDictionary representing JSON. Apparently the OP received the JSON correctly at least once and was able to parse it. — Hot Licks, Jan 14 '14 at 17:20
Thanks - i was mislead by "The incoming JSON stream looks like this"... — Rok Jarc, Jan 14 '14 at 17:24

score 1 · Answer 1 · answered Jan 23 '14 at 07:00

Problem is of with

NSDictionary *dict = responseObject[@"Images"]; NSArray *arr = [dict allValues];

responseObject[@"Images"]; returns you a NSArray class. So change you dict to NSArray class. and enumerate with that 'dict' object. You dont need to you arr object.

Can't retrieve the objects from a JSON steam to enumerate

1 Answers1