Parsing a JSON string into three arrays Objective C

Question

I am trying to use the data which I read from a text file in objective c. The data I read from the text file is:

{"aps":{"alert":"Test 1!","sound":"beep.wav","badge":5,"Type":"Banking"},"acme1":"bar","acme2":42}|{"aps":{"alert":"Test 2!","sound":"beep.wav","badge":5,"Type":"Banking"},"acme1":"bar","acme2":42}|{"aps":{"alert":"Test 3!","sound":"beep.wav","badge":5,"Type":"Banking"},"acme1":"bar","acme2":42}|{"aps":{"alert":"Test 4!","sound":"beep.wav","badge":5,"Type":"Banking"},"acme1":"bar","acme2":42}|{"aps":{"alert":"Test 5!","sound":"beep.wav","badge":5,"Type":"Banking"},"acme1":"bar","acme2":42}

Once read, I split the file into an array with a delimiter of "|". I then want to further separate it into 3 different arrays: banking, fraud and investment based on the key "Type". However I cannot seem to reach parse the JSON string once I split it into the array. My view did load method is below:

- (void)viewDidLoad {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *fileName = [NSString stringWithFormat:@"%@/AccountNotifications.txt", documentsDirectory];
    NSString *fileContents = [[NSString alloc]  initWithContentsOfFile:fileName usedEncoding:nil error:nil];
    NSArray *fileData = [fileContents componentsSeparatedByString:@"|"];

    if (fileContents != NULL)
    {
        bankingNotifications =  [[NSMutableArray alloc] init];
        fraudNotifications =  [[NSMutableArray alloc] init];
        investmentNotifications = [[NSMutableArray alloc] init];        

        for (i = 0; i < [fileData count]; i++)
        {
            NSString *notification = fileData[i];
            NSDictionary *json = [notification JSONValue];
            NSArray *items = [json valueForKeyPath:@"aps"];

            if ([[[items objectAtIndex:i] objectForKey:@"Type"] isEqual: @"Banking"])
            {
                [bankingNotifications addObject:fileData[i]];
                NSLog(@"Added object to banking array");
            }

            if ([[[items objectAtIndex:i] objectForKey:@"Type"] isEqual: @"Fraud"])
            {
                [fraudNotifications addObject:fileData[i]];
                NSLog(@"Added object to fraud array");

            }

            if ([[[items objectAtIndex:i] objectForKey:@"Type"] isEqual: @"Investment"])
            {
                [investmentNotifications addObject:fileData[i]];
                NSLog(@"Added object to investment array");

            }
        } }

There is an error with these three lines:

    NSString *notification = fileData[i];
    NSDictionary *json = [notification JSONValue];
    NSArray *items = [json valueForKeyPath:@"aps"];

Could you please help me parse the JSON strings into the three mutable arrays? The error I am getting is:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSDictionaryM objectAtIndex:]: unrecognized selector sent to instance 0x1d59db30'

Answer 1

If you create the text file yourself I would suggest you create a valid json object (as your data looks like it is supposed to be json) to keep your data nice and clean. similar to this:

{"aps":[{"type":"Banking","badge":5},{"Type":"Fraud","badge":12}]}

Then you can do following (this code is not tested, it can be that you have to amend it a bit) but i hope you'll get an idea :)

NSError*    error       = nil;
NSDictionary*    dict = nil;
//serialising the jsonobject to a dictionary
dict  = [NSJSONSerialization JSONObjectWithData:fileContents
                                              options:kNilOptions
                                                error:&error];
bankingNotifications =  [[NSMutableArray alloc] init];
fraudNotifications =  [[NSMutableArray alloc] init];
investmentNotifications = [[NSMutableArray alloc] init];

if (dict) {
    NSArray *dataArray = [dict objectForKey:@"aps"];
    NSDictionary* siteData    = nil;
    NSEnumerator* resultsEnum   = [dataArray objectEnumerator];
    while (siteData = [resultsEnum nextObject])
    {
        //
        if( [[siteData objectForKey:@"Type"] isEqualToString: @"Banking"]) {
            [bankingNotifications addObject:notification];
            NSLog(@"Added object to banking array");
        } else if ([[siteData objectForKey:@"Type"] isEqualToString: @"Fraud"])
        {
            [fraudNotifications addObject:notification];
            NSLog(@"Added object to fraud array");
        }
        else if ([[siteData objectForKey:@"Type"] isEqualToString: @"Investment"])
        {
            [investmentNotifications addObject:notification];
            NSLog(@"Added object to investment array");
        }

    }
}

Answer 2

The value for Key "aps" is a dictionary.

    NSDictionary *item = [json valueForKeyPath:@"aps"];

    if ([[item objectForKey:@"Type"] isEqualToString: @"Banking"])
    {
        [bankingNotifications addObject:notification];
        NSLog(@"Added object to banking array");
    } 
    else if ([[item objectForKey:@"Type"] isEqualToString: @"Fraud"])
    {
        [fraudNotifications addObject:notification];
        NSLog(@"Added object to fraud array");
    }
    else if ([[item objectForKey:@"Type"] isEqualToString: @"Investment"])
    {
        [investmentNotifications addObject:notification];
        NSLog(@"Added object to investment array");
    }