Question

I’m trying to figure out the best way to save my data.

Does it matter when you save data to the plist like so

NSString *error;
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *plistPath = [rootPath stringByAppendingPathComponent:@"yourFile.plist"];
NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:rootObj
                                                               format:NSPropertyListXMLFormat_v1_0
                                                     errorDescription:&error];
if(plistData) {
  [plistData writeToFile:plistPath atomically:YES];
}
else {
  NSLog(@"Error : %@",error);
  [error release];
}

or by using the NSData

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:FILE_NAME];

[myArray writeToFile:filePath atomically:YES];

I’m dealing with small XML files (which I parse into NSDictionaries) and large MP4 video. Are there any recommendations on which of these two file storage methods I should use? Thanks

Answer 1

I would go for [myArray writeToFile:filePath atomically:YES]; (fast, easy, less code)
But only when your NSArray or NSDictionaries only contains non-self objects (only contains NSNumber, NSString, NSArray, etc.).

If you use NSPropertyListSerialization you should probably use the option NSPropertyListBinaryFormat_v1_0. It’s faster and has smaller file size.

But you also need to think if it makes sense to parse a XML to then store into a XML Plist. 🙂
Yes. It can make sense because then you can handle them more easy.

You can also consider to parse your XML and store it in a CoreData database. It then makes querying more easy.

The MP4 videos i would store also in the NSDocumentDirectory.