How to fetch photos album title, image count in swift?

Question

I'm building Gallery app like a iOS standard Photos App. (Swift 4.1)

I want to fetch the thumbnails, titles, and total number of images that I can see when I launch the standard photo app.

The Photos framework seems more complex than I thought.

It is not easy to find a way to explain why, and what procedures should be approached.

Can you tell me about this?

Answer 1

The minimum number of steps to achieve what you are asking is:

  // import the framework
  import Photos

  // get the albums list
  let albumList = PHAssetCollection.fetchAssetCollections(with: .album, subtype: .albumRegular, options: nil)

  // you can access the number of albums with
  albumList.count
  // individual objects with
  let album = albumList.object(at: 0)
  // eg. get the name of the album
  album.localizedTitle

  // get the assets in a collection
  func getAssets(fromCollection collection: PHAssetCollection) -> PHFetchResult<PHAsset> {
    let photosOptions = PHFetchOptions()
    photosOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: true)]
    photosOptions.predicate = NSPredicate(format: "mediaType == %d", PHAssetMediaType.image.rawValue)

    return PHAsset.fetchAssets(in: collection, options: photosOptions)
  }

  // eg.
  albumList.enumerateObjects { (coll, _, _) in
        let result = self.getAssets(fromCollection: coll)
        print("\(coll.localizedTitle): \(result.count)")
    }

  // Now you can:
  // access the count of assets in the PHFetchResult
  result.count

 // get an asset (eg. in a UITableView)
 let asset = result.object(at: indexPath.row)

 // get the "real" image
 PHCachingImageManager.default().requestImage(for: asset, targetSize: CGSize(width: 200, height: 200), contentMode: .aspectFill, options: nil) { (image, _) in
        // do something with the image
    }

I also suggest to take a look at the Apple sample code for the Photos framework, is not hard to follow, together with the Photos framework documentation.