Parse.com Saving images sample. retrieve only one image - ios

Question

I have set up the sample from parse.com where you can upload an image from the camera and then display all the images in a grid view.
What I want is to display only the recent image taken instead of a total grid view.
The sample is located here : Parse example
The images is being downloaded and placed in some sort of grid view.
The use NSMutableArray *allImages; to get all the images.
The images is being output with button classes and a link to a new view.
The new view then only contains the image from the grid view (the one you click).
I would like to instead of downloading all of the images and placing them inside a grid view - just to display the latest image.
They code used to take the image from a small thumbnail to the full image view is like this:
// When picture is touched, open a viewcontroller with the image
PFObject *theObject = (PFObject *)[allImages objectAtIndex:[sender tag]];
PFFile *theImage = [theObject objectForKey:#"imageFile"];
NSData *imageData;
imageData = [theImage getData];
UIImage *selectedPhoto = [UIImage imageWithData:imageData];
PhotoDetailViewController *pdvc = [[PhotoDetailViewController alloc] init];
pdvc.selectedImage = selectedPhoto;
[self presentViewController:pdvc animated:YES completion:nil];
The code to get allImages is like:
// Contains a list of all the BUTTONS
allImages = [images mutableCopy];
// This method sets up the downloaded images and places them nicely in a grid
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
NSMutableArray *imageDataArray = [NSMutableArray array];
// Iterate over all images and get the data from the PFFile
for (int i = 0; i < images.count; i++) {
PFObject *eachObject = [images objectAtIndex:i];
PFFile *theImage = [eachObject objectForKey:#"imageFile"];
NSData *imageData = [theImage getData];
UIImage *image = [UIImage imageWithData:imageData];
[imageDataArray addObject:image];
}
// Dispatch to main thread to update the UI
dispatch_async(dispatch_get_main_queue(), ^{
// Remove old grid
for (UIView *view in [photoScrollView subviews]) {
if ([view isKindOfClass:[UIButton class]]) {
[view removeFromSuperview];
}
}
// Create the buttons necessary for each image in the grid
for (int i = 0; i < [imageDataArray count]; i++) {
PFObject *eachObject = [images objectAtIndex:i];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [imageDataArray objectAtIndex:i];
[button setImage:image forState:UIControlStateNormal];
button.showsTouchWhenHighlighted = YES;
[button addTarget:self action:#selector(buttonTouched:) forControlEvents:UIControlEventTouchUpInside];
button.tag = i;
button.frame = CGRectMake(THUMBNAIL_WIDTH * (i % THUMBNAIL_COLS) + PADDING * (i % THUMBNAIL_COLS) + PADDING,
THUMBNAIL_HEIGHT * (i / THUMBNAIL_COLS) + PADDING * (i / THUMBNAIL_COLS) + PADDING + PADDING_TOP,
THUMBNAIL_WIDTH,
THUMBNAIL_HEIGHT);
button.imageView.contentMode = UIViewContentModeScaleAspectFill;
[button setTitle:[eachObject objectId] forState:UIControlStateReserved];
[photoScrollView addSubview:button];
}
// Size the grid accordingly
int rows = images.count / THUMBNAIL_COLS;
if (((float)images.count / THUMBNAIL_COLS) - rows != 0) {
rows++;
}
int height = THUMBNAIL_HEIGHT * rows + PADDING * rows + PADDING + PADDING_TOP;
photoScrollView.contentSize = CGSizeMake(self.view.frame.size.width, height);
photoScrollView.clipsToBounds = YES;
});
});
I'm not an expert at this iOS-coding and I'm really just looking for a simple solution to display the recent image posted.

Answer 1

Looking through the posted example code, it would be a big undertaking to modify it to handle just a one image (mostly deleting a lot of yuck that synchs object ids). If you just want the quickest path to get started, you can do this:
// ...
// where you do the query for UserPhoto
[query orderByAscending:#"createdAt"];
// use the getFirst form of the query
[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) {
if (!error) {
// build the objects array that the demo code expects, but out of just one object
NSArray *objects = #[ object ];
// the remainder of the code as it is
A lot of UI code can get simpler, too. But the key is to skip all of the grid/button building code and do something like this:
// ...
// inside the method called setUpImages:
// this loop will only run once since we have only one object in the array
for (int i = 0; i < [imageDataArray count]; i++) {
PFObject *eachObject = [images objectAtIndex:i];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [imageDataArray objectAtIndex:i];
// you're essentially done here. add a big image view
// that replaces photoScrollView, then:
self.myBigImageView.image = image;
Hope that helps.