CODEWITHSUNDEEP
iphoneobjective-ciosnsmutablearray
Manpreet
Manpreet

Reputation: 9

Writing NSMutableArrray to file an then reading it

I have a NSMutableArray feed.leagues which has two objects of <MLBLeagueStandings: 0xeb2e4b0> I want to write it to a file and then read it from the file. This is what I have done:

- (void)encodeWithCoder:(NSCoder *)encoder {
    [encoder encodeObject:feed.leagues forKey:@"feed.leagues"];
}

- (id)initWithCoder:(NSCoder *)decoder {
    if (self = [super init]) {
        self.feed.leagues = [decoder decodeObjectForKey:@"feed.leagues"];
    }
    return self;
}

-(void)saveJSONToCache:(NSMutableArray*)leaguesArray {
    NSString *cachePath = [self cacheJSONPath];

    [NSKeyedArchiver archiveRootObject:feed.leagues toFile:cachePath];
    NSMutableArray *aArray = [NSKeyedUnarchiver unarchiveObjectWithFile:cachePath];
    NSLog(@"aArray is %@", aArray);
}

-(NSString*)cacheJSONPath
{

   NSString *documentsDirStandings = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
   NSString *cacheJSONPath = [NSString stringWithFormat:@"%@/%@_Standings.plist",documentsDirStandings, sport.acronym];
return cacheJSONPath;
}

Upvotes: 0

Views: 238

Answers (1)

Ashbay
Ashbay

Reputation: 1661

Your object : MLBLeagueStandings should be serializable and respond to NSCoding protocole :

@interface MLBLeagueStandings : NSObject <NSCoding>{

}

Now in your MLBLeagueStandings class file (.m) add the following methods :

- (id)initWithCoder:(NSCoder *)decoder;
{
  self = [super initWithCoder:decoder];
  if(self)
  {
    yourAttribute = [decoder decodeObjectForKey:@"MY_KEY"]
    //do this for all your attributes
  }
}

- (void)encodeWithCoder:(NSCoder *)encoder;
{
  [encoder encodeObject:yourAttribute forKey:@"MY_KEY"];
  //do this for all your attributes
}

In fact if you want to write an object to a file (in your case it's an array), all the object contained in this array have to conform to the NSCoding protocole.

Moreover if you want example : here is a good tutorial

Hope it will help you.

NB : if you want to encode/decode primitive type (int, float etc...) use :

[encode encodeInt:intValue forKey:@"KEY"];

(more information on apple doc)

Upvotes: 1

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