Populate UICollectionView Images From Document Directory AND Update Custom NSMutableArray object?

Question

In my data controller I have book objects and each object contains these properties (among others):

novel.title = @"Book One";
novel.imageArray = [[NSMutableArray alloc] initWithObjects: [UIImage imageNamed: @"book1image1"], nil];

In the app, users can add a book image using UIImagePickerController like this:

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(nonnull NSDictionary<NSString *,id> *)info {
[picker dismissViewControllerAnimated:YES completion:nil];

_addedImage = [info objectForKey:UIImagePickerControllerOriginalImage];
_addedImage = [self scaleImage:_addedImage toSize:CGSizeMake(120, 168)];

[_book.imageArray addObject:_addedImage];

NSString *stringPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0]stringByAppendingPathComponent:_book.imageArrayID];//folder name

NSError *error = nil;

if (![[NSFileManager defaultManager] fileExistsAtPath:stringPath])
    [[NSFileManager defaultManager] createDirectoryAtPath:stringPath withIntermediateDirectories:NO attributes:nil error:&error];

int i = 0;
for(_addedImage in _book.imageArray)
{
    _book.bookAddedToArray = YES;

    NSString *fileName = [stringPath stringByAppendingFormat:@"/image%i.jpg", i++];//image name
    NSData *data = UIImageJPEGRepresentation(_addedImage, 1.0);

    [data writeToFile:fileName atomically:YES];

}


[self.collectionView reloadData];

}

This works perfectly fine. All images are saved in the right place as expected.

As long as the app stays open, the new images can be viewed in the collectionView. You can navigate anywhere in the app, come back, and view the collectionView some more. When the app is completely exited out of and then reopened, the collectionView is reset and only shows the initial image that was set in the dataController (no matter what code I've implemented so far. It just always resets). All the user generated images are still in their respective folders in the documents directory but I cannot seem to update the cellForItemAtIndexPath: with the stored images presumably because the images are not being saved to the _book.imageArray. Right now I have the cell being populated by the default imagearray so, of course, that is what will show up. How do I update the array and pull from documents directory to show user images?

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:reuseIdentifier forIndexPath:indexPath];

if(_book.bookAddedToArray)
{

    //*** HOW TO UPDATE _BOOK.IMAGEARRAY ???? 


    cell.bookImageView.image = [_book.imageArray objectAtIndex:indexPath.row];

}
else
{

    cell.bookImageView.image = [_book.imageArray objectAtIndex:indexPath.row];

}

return cell;

}

I've read that you can store an array of directory paths in nsuserdefaults and retrieve it to populate an imagearray but I have yet to find a solution that works for me. None of the answers seem to address loading into a collectionview or tableview. Can anyone point me in the right direction? Please? Anyone? Lol. Let me know if you need to see more code. All suggestions are much appreciated!

Eventually the app will need to be rewritten as it has grown beyond the scope of my original code, but at this time, this is what I'm working with. I'll probably eventually use CoreData but I've even seen where people on S.O. recommended against storing images in CoreData and to use the documents directory. That still leaves me in this same situation then.

score 0 · Accepted Answer · answered Jun 05 '18 at 21:54

Yes! I got it figured out and it works like a charm. It seems that I could not actually update my custom NSMutableArray. I could make it read another array but could not actually change the array itself. (I'm referring to the _book.imageArray.)

Everything stayed the same in the didFinishPickingMediaWithInfo.

I didn't need to add anything to the cellForItemAtIndexPath. It is just simply:

if(_book.bookAddedToArray)
{
   cell.bookImageView.image = [_book.imageArray objectAtIndex: indexPath.row];
}

I created a property for my new array:

@property (nonatomic, strong) NSMutableArray *imagePathArray;

All the magic happens in ViewDidLoad.

- (void)viewDidLoad
{
    [super viewDidLoad];

    //initialize new array here
    _imagePathArray = [[NSMutableArray alloc] init];

    if (_book.bookAddedToArray)
    {
        int i = 0;

        //this is the path to the folder. 
        NSString *stringPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0]stringByAppendingPathComponent:_book.imageArrayID];

        int z;

        NSArray *directoryContent = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:stringPath error:NULL];
        for (z = 0; z < (int)[directoryContent count]; z++)
        {
            //this is the path to each image file
            NSString *fileName = [stringPath stringByAppendingFormat:@"/image%i.jpg", i++];
            NSLog(@"imagefile = %@", fileName);

            UIImage *fileNameImage = [UIImage imageWithContentsOfFile:fileName];

            //add each image to a new array
            [_imagePathArray addObject:fileNameImage];
        }

         //set my array to the new array
         _book.imageArray = _imagePathArray;

}


}

I can thank this post for helping to read the images within each folder: go to link.

//these are all properties in my Data Class.
    _book.imageArrayID 
    _book.bookAddedToArray
    _book.imageArray

I hope this helps someone out!

Populate UICollectionView Images From Document Directory AND Update Custom NSMutableArray object?

1 Answers1