Parsing a JSON of unknown Structure Objective-C - objective-c

Question

I am trying to parse this json and am not sure of parsing this because the keys like "vis-progress-control" might change and I am trying to build a general code which parses this type of a json. I am sure that "type" key will be present in the json structure.
NSDictionary *dict = [sData JSONValue];
NSArray *items = [dict valueForKeyPath:#"assets"];
NSLog(#"%#", items);
for (NSString *key in [[dict objectForKey:#"assets"]allKeys]) {
for (NSString *subKey in [[[dict objectForKey:#"assets"] objectForKey:key]allKeys]) {
NSLog(#"Value at subkey:%# is %#\n",subKey,[[[dict objectForKey:#"assets"]objectForKey:key]objectForKey:subKey]);
}
}
I am using the SBJson Library on Github. My actual issue is How do I access "direction", "degrees" etc when I do not know the "vjs-progress-holder" key?
I have also a widgets array nested within a widgets array. How do I get these values as well?

Answer 1

Read about tree traversal. Sounds like you want to traverse the "tree" of nodes and when you find a particular leaf value you will then traverse back up one level and know the parent is the container you want.
So the idea is that once it's parsed from the JSON, forget it's JSON because now it's just a tree in arrays and dictionaries. Traverse it by getting all the keys in the dictionary via allKeys (returns an array of keys) and then iterate through them getting the associated values (using something like (psuedo code):
for ( NSString * key in allkeysarray) {
NSString * val = [dict objectForKey: key];
if ( [val isEqualToString: #"gradient"] )
{
// now you know that this dictionary is the one you're looking for so you can maybe break out of this loop and just use the keys you know reference these values.
break;
}
}
hopefully that's enough to get you going.

Answer 2

Assuming I'm understanding your objective here, it seems like you want to do something like this?
NSDictionary *outerDict = [sData JSONValue];
NSDictionary *assets = outerDict[#"assets"];
for (NSDictionary *asset in [assets allValues]) {
NSString *type = asset[#"type"];
if ([type isEqualToString:#"gradient"]) {
float degrees = [asset[#"degrees"] floatValue];
// and read whatever other values you need for gradients
}
if ([type isEqualToString:#"image"]) {
// and read the appropriate values for images here...
}
}
So I'll make a different assumption here, which is that you want an array of gradients. So then that looks basically like this:
NSDictionary *outerDict = [sData JSONValue];
NSDictionary *assets = outerDict[#"assets"];
NSMutableArray *gradients = [NSMutableArray array];
for (NSDictionary *asset in [assets allValues]) {
NSString *type = asset[#"type"];
if ([type isEqualToString:#"gradient"]) {
// Add this asset to the list of gradients:
[gradients addObject:asset];
}
if ([type isEqualToString:#"image"]) {
// do something similar for images
}
}
Then, after having done that, if you would like to read the "degrees" field for the 4th gradient, for example, you will find it at gradients[3][#"degrees"]