Parsing nested json in iOS using Mantle - ios

Question

I'm trying to parse data received from a service using the framework Mantle. The json has nested data and I am having problems to parse it. The json is like the following:
{
"sections": [
{
"title": "title1",
"level": 1,
"content": [
{
"type": "type1",
"text": "text1"
}
],
"images": []
},
{
"title": "title2",
"level": 2,
"content": [
{
"type": "type2",
"text": "text2"
},
{
"type": "type9",
"text": "text9"
},
{
"type": "type4",
"text": "text4"
},
{
"type": "type6",
"text": "text6"
}
],
"images": [
{
"src": "http://cvbcvcv",
"caption": "caption"
}
]
}]
}
The class that I am using is:
// MainObject.h
#interface MainObject : MTLModel <MTLJSONSerializing>
#property (strong, nonatomic) NSArray *sectionsArray;
+ (NSValueTransformer *)sectionsArrayJSONTransformer;
#end
#interface Section : MTLModel <MTLJSONSerializing>
#property (strong, nonatomic) NSString *title;
#property (assign, nonatomic) NSString *level;
#property (strong, nonatomic) NSArray *content;
#property (strong, nonatomic) NSArray *images;
+ (NSValueTransformer *)contentJSONTransformer;
+ (NSValueTransformer *)imagesJSONTransformer;
#end
#interface Content : MTLModel <MTLJSONSerializing>
#property (strong, nonatomic) NSString *type;
#property (strong, nonatomic) NSString *text;
#end
#interface Image : MTLModel <MTLJSONSerializing>
#property (strong, nonatomic) NSString *src;
#property (strong, nonatomic) NSString *caption;
#end
and
//MainObject.m
#implementation MainObject
+ (NSDictionary *)JSONKeyPathsByPropertyKey
{
return #{
#"sectionsArray" : #"sections",};
}
+ (NSValueTransformer *)sectionsArrayJSONTransformer
{
return [MTLJSONAdapter dictionaryTransformerWithModelClass:[Section class]];
}
#end
#implementation Section
+ (NSDictionary *)JSONKeyPathsByPropertyKey
{
return #{
#"title" : #"title",
#"level" : #"level",
#"content" : #"content",
#"images" : #"images",};
}
+ (NSValueTransformer *)contentJSONTransformer
{
return [MTLJSONAdapter arrayTransformerWithModelClass:[Content class]];
}
+ (NSValueTransformer *)imagesJSONTransformer
{
return [MTLJSONAdapter arrayTransformerWithModelClass:[Image class]];
}
#end
#implementation Content
+ (NSDictionary *)JSONKeyPathsByPropertyKey
{
return #{
#"type" : #"type",
#"text" : #"text",};
}
#end
#implementation Image
+ (NSDictionary *)JSONKeyPathsByPropertyKey
{
return #{
#"src" : #"src",
#"caption" : #"caption",};
}
#end
Then, when I make the call to the service and try to parse the json with the following code, being responseObject the data obtained from server, the data appears nil:
for (NSArray *array in [responseObject valueForKey:#"sections"]) {
NSArray *seccionArray = [MTLJSONAdapter modelsOfClass:[Section class] fromJSONArray:array error:nil];
}
I have tried a lot of ways to parse this data well, but the app always crashes or returns nil. I hope you can help me to solve this

Answer 1

Why can't just one line using NSJSONSerialization?
NSMutableDictionary *yourArray = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
Then you fetch what you want from your array...