Adding Items to plist from another plist on app launch - ios

Question

My app is a list of items that the user can rate and take notes on etc. All of these items (dictionaries that store the user ratings and notes) are stored in a plist which is moved to the documents directory when the app first loads (if the plist file already exists in documents directory it skips this step). Now I've had a few reviews and people have been saying there should be more items in the lists. Now I'm trying to figure out how to go about adding new items to the plist. If I add them to the existing plist the users will never see the new items because the app checks to see if the database already exists in the documents directory. So they will never receive the new list. So I planned on creating a new plist with items in it and appending each new item to the old plist if the item doesn't already exist (because the user can add items themselves so I don't want to have duplicate entries in case the user added an item with the same name). My dilemma is I'm not sure where exactly/how to do the plist merging. Do I do it in the App Delegate? Do I do it in the viewDidLoad of the main view? How do I stop it from checking every time the app loads if it has already added the new items to the old plist? I know there are different ways to do it. I'm just looking for the easiest and "less load heavy on the app" way of doing it.

Answer 1

Ok. I solved it thanks to a couple people in one of the iOS chats. So basically inside the application didFinishLaunchingWithOptions method in my AppDelegate.m I loaded both plists into 2 different NSArrays array1 and array2, I also created an NSMutableArray array3 which I loaded with the original plist that was in the users documents directory.Then I looped through them both checking to make sure I didn't add any duplicate items based on their Name_Key (because the items in the arrays are dictionaries). If the items didn't match then I would add them to the 3rd array (array3). Then I saved array3 out to the original plist file path. Then I set an integer inside the user defaults so It would only perform this task once. I didn't want the app to go through this EVERY time the user opened the app. Below is the code I used.
int haveMergedPlist = [[NSUserDefaults standardUserDefaults] integerForKey:#"merged plist"];
if (haveMergedPlist < 1){
// I used a integer rather than a BOOL because if I ever want to perform this operation again with another app update all I have to do is change the number.
// merge code here
//new plist
NSString *newPlistPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"NewPlist.plist"];
NSArray *newPlistArray = [[NSArray alloc]initWithContentsOfFile:newPlistPath];
//original plist in user documents directory
NSArray *searchPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [searchPaths lastObject];
NSString *originalPlistPath = [documentsDirectory stringByAppendingPathComponent:#"originalPlist.plist"];
NSArray *originalPlistArray = [[NSMutableArray alloc]initWithContentsOfFile:originalPlistPath];
NSMutableArray *combinedPlistArray = [[NSMutableArray alloc]initWithContentsOfFile:originalPlistPath];
// Loop through both plists arrays and add if it does not match/exist.
BOOL itemExists = YES;
for (NSDictionary *newItem in newPlistArray) {
for (NSDictionary *originalItem in originalPlistArray) {
NSString * newItemNameString = [[newItem objectForKey:NAME_KEY] lowercaseString];
NSString * origItemNameString = [[originalItem objectForKey:NAME_KEY] lowercaseString];
//Compare lowercase strings and if they don't match then add them to the original plist array.
if ([newItemNameString isEqualToString:origItemNameString]) {
itemExists = YES;
break;
} else {
itemExists = NO;
//doesn't match so add it
}
}
if (itemExists == NO) {
[combinedPlistArray addObject:newItem];
NSLog(#"newItem added");
itemExists = YES;
}
}
//Write Array With New Items Added to documents directory
NSString *writeableDBPath = [documentsDirectory stringByAppendingPathComponent:#"originalPlist.plist"];
[combinedPlistArray writeToFile:writeableDBPath atomically:YES];
//set integer to 1 in user defaults so it only merge's once
//I comment this out while getting the loops to work otherwise you will have to delete the app out of the simulator or the phone to make sure its working every time.
[[NSUserDefaults standardUserDefaults] setInteger:1 forKey:#"merged plist"];
}