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iOS

Posted by Jonah Kesoyan
Jonah Kesoyan
2,055 Points

UICollectionView and Parse

If you have photos stored in Parse, how can you place them in a UICollectionView?

2 Answers

muqbilhashi
muqbilhashi
1,498 Points
muqbilhashi
muqbilhashi
1,498 Points

UICollectionView is similar to UITableView. If you are not familiar with UICollectionViewController, I suggest you spend sometime reading and understanding UICollectionViewController. If you are familiar with UICollectionViewController, share what you have done so far so we can better help you.

Jonah Kesoyan
Jonah Kesoyan
2,055 Points 
@property (nonatomic) NSArray *photos;

@end

@implementation GalleryViewController

-(instancetype ) initWithCoder:(NSCoder *)aDecoder {

    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    layout.itemSize = CGSizeMake(106.0, 106.0);
    layout.minimumInteritemSpacing = 1.0;
    layout.minimumLineSpacing = 1.0;

    return (self = [super initWithCollectionViewLayout:layout]);
}

-(void)viewDidLoad {
    [super viewDidLoad];

    self.title = @"Gallery";

    [self.collectionView registerClass:[PhotoCell class] forCellWithReuseIdentifier:@"photo"];
    self.collectionView.backgroundColor = [UIColor whiteColor];

//    [self refresh];


}


-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return [self.photos count];
}

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    PhotoCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"pic" forIndexPath:indexPath];

     return cell;
}

THIS IS THE CLASS ASSOCIATED WITH UICOLLECTIONVIEWCONTROLLER, HOW WOULD I GET THE PHOTOS FROM PARSE IN THE COLLECTION VIEW?

muqbilhashi
muqbilhashi
1,498 Points
muqbilhashi
muqbilhashi
1,498 Points 
- (void)viewDidLoad {
     [super viewDidLoad];

    [self getPhotosFromParse];
}

- (void)getPhotosFromParse {

    PFQuery *query = [PFQuery queryWithClassName:@"Photos"]; 

[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (error) {
            NSLog(@"Error %@ %@", error, [error userInfo]);
        }
 else
 {
            self.photos = objects;

        }
    }];
}

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    PhotoCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"pic" forIndexPath:indexPath];

 UIImage *myImage = [UIImage imageNamed:@"PlaceholderPhoto.png"];
    PFImageView *imageView = [[PFImageView alloc] init];
    imageView.image = myImage;
    cell.myImageView.image = imageView.image;
    PFFile *pImage = [self.photos objectAtIndex:indexPath.row] ; 
    imageView.file = pImage;

    [imageView loadInBackground:^(UIImage *image, NSError *error) {
        if (!error) {
            cell.myImageView.image = image;

        }
    }];

     return cell;
}

This is rough draft.. I have not tested. This is just for retrieving images from parse and displaying placeholder image briefly while the image is loading in the background. hope this helps