iphone - How to save file in the documents folder?

Question

I am trying to save data in the documents folder on iPhone 5.1 simulator.

 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory, @"myData.json"];

if ([[NSFileManager defaultManager] isWritableFileAtPath:filePath]) {
    NSLog(@"Writable");
}else {
    NSLog(@"Not Writable");
}

I've got always "Not Writable". Any idea? Please help me.

Answer 1

Maybe because you have not created the file, the file you tested does not exist. :)

You can do this to find the problem,

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory, @"myData.json"];
NSLog(@"filePath %@", filePath);

if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]) { // if file is not exist, create it.
    NSString *helloStr = @"hello world";
    NSError *error;
    [helloStr writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error];
}

if ([[NSFileManager defaultManager] isWritableFileAtPath:filePath]) {
    NSLog(@"Writable");
}else {
    NSLog(@"Not Writable");
}