Failed to write my custom dictionary data into plist file

Question

I am trying to write data into my plist file, which was created in Library/Caches in my app's sandbox, with the following custom helper method:

-(void)saveStatusesToPlist:(NSArray *)array
{
    NSDictionary *dict = @{@"data": array};

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
    NSString *cachesDirectory = [paths objectAtIndex:0];

    NSString *plistPath = [cachesDirectory stringByAppendingPathComponent:filepath];
    NSLog(@"PATH: %@", plistPath);

    NSFileManager *manager = [NSFileManager defaultManager];
    if (![manager fileExistsAtPath:plistPath]) {
        BOOL isCreated = [manager createFileAtPath:plistPath contents:nil attributes:nil];
        NSLog(@"Result：%@", isCreated? @"Success": @"Failed");
    }
    BOOL flag = [dict writeToFile:plistPath atomically:YES];
    NSLog(@"Write result：%@", flag? @"Success": @"Failed");
}

Please notice that the parameter: array is an array of many NSDictionary objects converted from JSON data which was fetched from server side over network.

UPDATE: I got my array like this:

NSArray *array = [result objectForKey:@"array"];

But the result was always failed.

So I doubted that issue was from the array which may contain invalid data. Then I tried hardcode the array to sth like @[@"key1": @"value1", @"key2": @"value2", @"key3": @"value3"].

With the hardcoded data, the flag returns YES meaning it was saved.

So at least I can tell that my fetched data has some problem but I don't know where it is.

UPDATE: Here is my dictionary data which is very large:

Answer 1

Seems like issue is in Dictionary's size… I created array with 30 dictionaries with 40 items on each. And I can't write it… BUT!!! ;) You can make something like this:

NSData* data = [NSKeyedArchiver archivedDataWithRootObject:dict]; 
BOOL flag = [data writeToFile:plistPath atomically:YES];

NSData* savedData = [NSData dataWithContentsOfFile:plistPath];
NSDictionary* unarchivedDict = (NSDictionary*) [NSKeyedUnarchiver unarchiveObjectWithData:savedData];

In this case - everything works fine.