JSONModel returns nil

Question

I\'mm using JSONModel to get the JSON from the URL. It\'s a very simple object, containing only 2 strings - \"name\" and \"url\".

First I made the Object Model:

Answer 1

Explanation:

First of all JSONModel expects your JSON top object to be a dictionary, only that way it can match its keys to a model's properties.

Your model called TutorialFeed expects to be fed JSON matching the property name "tutorials".This means your JSON feed must be in the form:

{ "tutorials": [{obj1}, {obj2}, {obj3}, ...] }

What you have in fact at: http://api.matematikfessor.dk/apps/teacher_videos is

[{obj1}, {obj2}, {obj3}]

That's why your model instance is in fact "nil" because the JSON structure didn't match what your model expects.

Solution:

If you have an array at the top of your JSON feed (like the one on the URL you use) you have two options:

1) introduce a new key in your JSON feed - i.e. alter the JSON to be in the form of {"tutorials": [obj1, obj2, etc...]}

2) You can use another method to parse the JSON feed. Look up the docs here and use the static method that parses a list of objects:

#import "JSONModel+networking.h"
...
[JSONHTTPClient   
  getJSONFromURLWithString:@"http://api.matematikfessor.dk/apps/teacher_videos"
  completion:^(id feed, JSONModelError *err) {
    NSArray* tutorials = [Tutorial arrayOfModelsFromDictionaries: feed];
    NSLog(@"tutorials: %@", tutorials);
  }];