iOS JSON Parsing, array with multiple array - ios

Question

I have a JSON array with multiple object and I don't know how do I grab the "url" tag as an NSArray or a NSDictionary and show that image url in Tableview. I can't change the JSON data format.How should I do this?
Here is what the JSON response looks like:
{
"meta": {
"total_count": 10
},
"pages": [
{
"id": 7,
"meta": {
"type": "dashboard.NewsEvents",
"detail_url": "http://suno.to/api/v1/pages/7/"
},
"title": "NoEvent",
"created_at": "2016-03-06T10:42:19.646000Z",
"cover_url": [
[
{
"url": "/media/images/Maha_Shivratri2.original.jpg",
"title": "Maha Shivratri2.jpg"
},
{
"url": "/media/images/Maha_Shivratri1.original.jpg",
"title": "Maha Shivratri1.jpg"
}
],
[
{
"url": "/media/images/Celebrations.original.jpg",
"title": "Celebrations.jpg"
},
{
"url": "/media/images/Crew.original.jpg",
"title": "Crew.jpg"
},
{
"url": "/media/images/World_record.original.jpg",
"title": "World record.jpg"
},
{
"url": "/media/images/AI_pilots.original.jpg",
"title": "AI pilots.jpg"
}
],
[
{
"url": "/media/images/CbVv-VbWEAAmwv_.original.jpg",
"title": "DAL SWARAJ YATRA"
},
{
"url": "/media/images/CbVv_-TWwAE7RjM.original.jpg",
"title": "DAL SWARAJ YATRA"
},
{
"url": "/media/images/CbVv_SmXIAALQP8.original.jpg",
"title": "DAL SWARAJ YATRA"
},
{
"url": "/media/images/CahEc--UkAArc_z.original.jpg",
"title": "DAL SWARAJ YATRA"
}
]
]
},
{
"id": 2530,
"meta": {
"type": "dashboard.NewsEvents",
"detail_url": "http://suno.to/api/v1/pages/2530/"
},
"title": "World Culture Festival",
"created_at": "2016-03-12T06:59:21.023000Z",
"cover_url": [
[
{
"url": "/media/images/Security.original.jpg",
"title": "Security check"
}
],
[
{
"url": "/media/images/Elephant_statues.original.jpg",
"title": "Elephant"
}
],
[
{
"url": "/media/images/6.original.jpg",
"title": "Stage"
},
{
"url": "/media/images/4.original.jpg",
"title": "Stage"
}
]
]
},
{
"id": 2675,
"meta": {
"type": "dashboard.NewsEvents",
"detail_url": "http://suno.to/api/v1/pages/2675/"
},
"title": "Holi in Barsana",
"created_at": "2016-03-17T12:35:09.308000Z",
"cover_url": [
[
{
"url": "/media/images/Brajwasi_playing_holi_.original.jpg",
"title": "Holi in Barsana"
},
{
"url": "/media/images/dancing_.original.jpg",
"title": "Holi in Barsana"
},
{
"url": "/media/images/holi.._.original.jpg",
"title": "Holi in Barsana"
},
{
"url": "/media/images/holi..._.original.jpg",
"title": "Holi in Barsana"
}
],
[
{
"url": "/media/images/Lathmar_holi_19_n54f7LJ.original.jpg",
"title": "Lathmar Holi in Barsana"
}
],
[
{
"url": "/media/images/Lathmar_holi_17.original.jpg",
"title": "Lathmar Holi in Barsana"
},
{
"url": "/media/images/Lathmar_holi_20.original.jpg",
"title": "Lathmar Holi in Barsana"
}
]
]
},
I'm using this code to get the "url" array. Plz correct me ?
NSArray *imageUrlArray = [[self.jsonData objectAtIndex:indexPath.row]objectForKey:#"cover_url"];
NSLog(#"IMAGE URL ARRAY:%#",imageUrlArray);
NSString *imageUrl = [imageUrlArray valueForKey:#"url"];
NSLog(#"IMAGE URL:%#",imageUrl);

Answer 1

To view the JSON structure - http://jsonviewer.stack.hu/
NSMutableArray* imageurlArray = [NSMutableArray new];
NSArray* jsonArray = jsonData[#"pages"];
for (int i = 0; i<[jsonArray count]; i++) {
NSArray* coverUrlArray = jsonArray[i][#"cover_url"];
for (int t = 0; t< [coverUrlArray count]; t++) {
NSArray* UrlArray = coverUrlArray[t];
for (int x = 0; x<[UrlArray count]; x++) {
[imageurlArray addObject:UrlArray[x][#"url"]];
}
}
}
NSLog(#"imageurlArray: %#", imageurlArray);
//imageurlArray contains all url
//In cell for row at indexpath --> use imageurlArray[indexPath.row];

Answer 2

You have array wrappped by another array.
So, use this direction:
NSDictionary *json=//..initialized
NSArray *pages = [json valueForKey#"pages"];
NSDictionary *page = [pages objectAtIndex:0];
NSArray *ar1 = [page valueForKey#"cover_url"];
NSArray *ar2 = [ar1 objectAtIndex:0];
NSDictionary *elem = [ar2 objectAtIndex:0];
NSString *value = [elem valueForKey#"url"];

Answer 3

I would suggest using Mantel or JSONModel libraries for parsing objects and having decent DTOs.

Answer 4

When you deal with something like this, i suggest putting the complete json in http://jsonviewer.stack.hu/ so you can see the correct structure without getting confused.
Then it's just a matter of digging. When you see { }, you add a dictionary, when you see [ ], you add an array, until you reach your url object :)
I'm not writing the code because it is pretty trivial, just a mix of objectForKeys for dictionaries and objectAtIndex for arrays.
The last layers are just objects, so they're handled like any other object.
If you're confused about json, I suggest you try giving your json-parser a simple json (you hard core it yourself just above, its really just for testing).
Small advice :
Give it a simple array of 1 object, then 2, then put the array in a dict, then two, etc. and you keep making the json more complex until you really understand how it works. Then you'll eventually have a fake json just like your real one, and you can remove the fake and use the real one :)
Other advice :
There are many json parsing libraries that let you create the object model, where you can create (for example) a Page object that has an ID, a title, a cover URl, etc. that matches the JSON structure, and then you just tell the parser " make that JSON a Page!" and voilà, you have a Page. I don't know any of those json libraries in ios, but people will surely link it here, so try it out ! They're super easy to use and make json parsing really straightforward. And also, you don't have to map everything manually like you're doing ;)