Question

I’m using the below bit of code to add a new array into a plist, but each time I add a new array with the textfield in my app it overwrites the old one even though it has a brand new key.. any ideas?

- (IBAction)saveViewerItems
{
    // get paths from root direcory
    NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
    // get documents path
    NSString *documentsPath = [paths objectAtIndex:0];
    // get the path to our Data/plist file
    NSString *plistPath = [documentsPath stringByAppendingPathComponent:@"Data.plist"];

    // set the variables to the values in the text fields
    self.data = [[NSMutableArray alloc] initWithCapacity:20];


    // create dictionary with values in UITextFields
    NSDictionary *plistDict = [NSDictionary dictionaryWithObjects: [NSArray arrayWithObjects: data, nil] forKeys:[NSArray arrayWithObjects: (@"%@", text), nil]];

    NSString *error = nil;
    // create NSData from dictionary
    NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:plistDict format:NSPropertyListXMLFormat_v1_0 errorDescription:&error];

    // check is plistData exists
    if(plistData)
    {
        // write plistData to our Data.plist file
        [plistData writeToFile:plistPath atomically:YES];
    }
}

Answer 1

In order to get the dictionaty already in the file, use:

NSMutableDictionary *dictionary = [NSMutableDictionary dictionaryWithContentsOfFile:(NSString *)filePath];

In order to write another array in that dictionary (using a different key), use:

[dictionary setObject:(id)myArray forKey:(NSString *)myKey];

In order to write back to the file, use:

[dictionary writeToFile:(NSString *)filePath atomically:YES];

There is no need to use NSData class. For more info, check out Apple NSDictionary Class