Can't parse json Data via YAJLiOS

Question

At first i'm trying to access local file in my app folder:

    NSData *data = [NSData dataWithContentsOfFile:
                                      [@"countries.json" stringByExpandingTildeInPath]];

result is always NULL

then i tried to check is file exists:

    NSString* documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString* foofile = [documentsPath stringByAppendingPathComponent:@"countries.json"];
    BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:foofile];

it doesn't exist, and i use following code to access my json file:

    NSString *data1 = [[NSBundle mainBundle] pathForResource:@"countries" ofType:@"json"];
    NSData *data2 = [[NSData alloc] initWithContentsOfFile:data1];

it getting the file but when i try to parse it:

    NSDictionary *dict1 =[data2 yajl_JSON];

i getting an error:

    [NSConcreteData yajl_JSON]: unrecognized selector sent to instance 0x6838d60

My questions is next:

Is there any chance to convert NSData to NSConcreteData?
Am i using the right approach to access data?

Api documentation - http://gabriel.github.com/yajl-objc/

Screenshot of my Xcode Build Phases:

enter image description here

i think that my main problem it that i using wrong approach to access data — Vlad Z., Apr 28 '12 at 21:23
Also, regarding NSConcreteData, see the answer to this question here: http://stackoverflow.com/questions/1113811/what-is-nsconcretedata-and-where-is-it-defined — jonkroll, Apr 28 '12 at 22:39
and i treat NSConcreteData like NSData but i suppose that YAJLiOS don't — Vlad Z., Apr 28 '12 at 23:01
The questions are: 1. Did you link against the YAJL library / sources? 2. Does YAJL actually provide a category on NSData offering a method called yajl_JSON? — Till, Apr 28 '12 at 23:04

Till · Accepted Answer · 2012-04-28T23:44:28.200

3

According to the YAJL documentation the method you are trying to invoke does in fact exist.

That leaves only one option; you have not fully linked against the YAJL framework.

Make sure it shows up within the list of linked frameworks/libraries of your App target just like CFNetwork.framework shows up in my example.

enter image description here

Since the method you are trying to invoke is in fact part of a category on NSData, make sure you include -ObjC in your Other Linker Flags.

enter image description here

From Apple's Technical Q&A.

This flag causes the linker to load every object file in the library that defines an Objective-C class or category. While this option will typically result in a larger executable (due to additional object code loaded into the application), it will allow the successful creation of effective Objective-C static libraries that contain categories on existing classes.

edited Apr 28 '12 at 23:44

answered Apr 28 '12 at 23:13

Till

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i's linked - http://s13.postimage.org/xwxtjiqh3/Screen_Shot_2012_04_29_at_2_19_41_AM.png (screenshot of my Xcode Build Phases) – Vlad Z. Apr 28 '12 at 23:21
Thanks! this works. At first i thought it would only work on the simulator, but it also works on real device! – Vlad Z. Apr 28 '12 at 23:45
1

The linker flag is tricky and a common pitfall when using custom/third party libraries that contain categories. Been there, got the Tshirt :D.. – Till Apr 28 '12 at 23:47

Can't parse json Data via YAJLiOS

1 Answers1