Question

In my code I have an item that is a list of alternating strings and images that I wish to save. I know how to save individual images in their JPEG representations, but is there a simple and efficient way I don’t know of in Objective-C to save all these items (or at least the images since I can handle the strings myself) while maintaining their order?

ex: item 1 (“hi”, image, “how”, image, “are”, image), item2(“this”, image, “is”, image)

maintaining item order is not important to me, but the order in the list is. The first thing that comes to mind is simply to save every single image, and have an algorithm to create then remember their imagename and then save and load the text list. Is there an easier way to do this? Can I literally just save the array itself as a plist and be on my merry way? (i’ve only seen examples of these with strings)

Answer 1

I believe I understand what you’re going for. You’d like to save an array of items, each of which contains an array of Objects that contain an image and a string. If this is accurate then you’re idea of saving the array to a plist is correct.

In short you would create NSDictionaries of your Objects and save the array of them. Like so:

In your object you’ll have a method similar to this:

- (NSDictionary *)dictionaryOfItemData;
{
    NSMutableDictionary * mutableDictionary = [[NSMutableDictionary alloc] init];


    [mutableDictionary setObject:imageName 
                          forKey:@"imageName"];

    [mutableDictionary setObject:UIImagePNGRepresentation([self image]) 
                          forKey:@"imageData"];


    return mutableDictionary;
}

Then you would save an array of these (or array of arrays, or whatever your desire based on file size concerns, need to load, etc.) like so in the proper place:

[[arrayOfDictionaries description] writeToFile:path
                                    atomically:YES 
                                      encoding:NSUTF8StringEncoding 
                                         error:NULL];

Which gives you the plist, that you can load and hydrate by creating your image with data and setting the image name from the dictionary.

~Good Luck