Objective C Acessing NSMutableDictionay inside NSMutableDictionary - objective-c

Question

I am a newcomer to objective C and I have serious problems in accessing NSMutableDictionarys.
I have two objects (Network and Beacon), and I want to create a NSMutableDictionary of Networks with a NSMutableDictionary of Beacons inside.
Network.h
#import <Foundation/Foundation.h>
#interface Network : NSObject{
NSString *id_network;
NSString *major;
NSString *active;
NSString *name;
NSString *status;
NSMutableDictionary *beaconsDictionary;
}
#property (nonatomic, strong) NSString *id_network;
#property (nonatomic, strong) NSString *major;
#property (nonatomic, strong) NSString *active;
#property (nonatomic, strong) NSString *name;
#property (nonatomic, strong) NSString *status;
#property (nonatomic, strong) NSMutableDictionary *beaconsDictionary;
#end
Beacon.h
#import <Foundation/Foundation.h>
#interface Beacon : NSObject{
NSString *id_beacon;
NSString *major;
NSString *minor;
NSString *active;
NSString *detected;
}
#property (nonatomic, strong) NSString *id_beacon;
#property (nonatomic, strong) NSString *major;
#property (nonatomic, strong) NSString *minor;
#property (nonatomic, strong) NSString *active;
#property (nonatomic, strong) NSString *detected;
#end
I can create the NSMutableDictionary like this:
Beacon *beacon = [[Beacon alloc]init];
beacon.id_beacon=#"1";
beacon.major=#"1";
beacon.minor=#"1";
beacon.active=#"1";
beacon.detected=#"0";
NSMutableDictionary *beaconDic = [[NSMutableDictionary alloc]init];
[beaconDic setObject:beacon forKey:beacon.id_beacon];
Network *net = [[Network alloc]init];
net.id_network=#"1";
net.major=#"1";
net.active=#"1";
net.name=#"network 1";
net.status=#"1";
net.beaconsDictionary=beaconDic;
NSMutableDictionary *networkDic = [[NSMutableDictionary alloc]init];
[networkDic setObject:net forKey:net.id_network];
Ok, but now how can i access to beacon property "detected" directly and modify it?
I know this this is a very bad example, but I have no idea how to do it.

Answer 1

It looks like you'll have to have a network id and a beacon id to get where you need to go. It would looks something like:
Network *net = networkDic[netId];
Beacon *beacon = net.beaconsDictionary[beaconId];
beacon.detected = newDetectedValue;
This is for arbitrary network ids and beacon ids. You can hardcode values if you wish.
Edit:
It's worth noting in your example code that you can use the more modern dictionary assignment. Rather than [dictionary setValue:value forKey:key];, you can do dictionary[key] = value;. It's, of course, personal preference but you're very likely to see the latter in more recent things and I find it to be clearer.

Answer 2

You can get your Network and Beacon objects back by providing keys that match their keys in the dictionary:
NSString *nwKey = #"1";
Network *n = networkDic[nwKey];
NSDictionary *bDict = n.beaconsDictionary;
NSString *bnKey = #"1";
Beacon *b = bDict[bnKey];
Note: This is the new syntax. Here is the old one:
NSString *nwKey = #"1";
Network *n = [networkDic objectForKey:nwKey];
NSDictionary *bDict = n.beaconsDictionary;
NSString *bnKey = #"1";
Beacon *b = [bDict objectForKey:bnKey];