Abhinav Abhinav - 3 months ago 150
Swift Question

Alamofire Image : Placeholder image is not set for af_setImageWithURL

I am using

af_setImageWithURL
Alamofire API to fetch the table cell images and pass a default placeholder image:

let defaultImage = UIImage(named:"myImage")
cell.imageView.af_setImageWithURL(imageURL, placeholderImage:defaultImage, imageTransition: .CrossDissolve(0.1))


Problem: When my image does not exists at the downloading path, cell do not show the default image as well. When I scroll the table up & down (to purge and re-use the same cell) then it shows up.

EDIT:

Noticed this is happening after dequeuing the cell, I reset the image first and then call Alamofire. If I comment out below line, it works fine but then I am running into a risk of showing old product image if both image URL and default images are not available.

cell.imageView.image = nil


Anybody faced similar issue, please advise.

Answer

You need to make sure you cancel your request and also nil out the image in prepareForReuse. Otherwise you can run into a few different problems. Here's the ImageCell class in the iOS Example in AFI.

class ImageCell: UICollectionViewCell {
    class var ReuseIdentifier: String { return "org.alamofire.identifier.\(type(of: self))" }
    let imageView: UIImageView

    // MARK: - Initialization

    override init(frame: CGRect) {
        imageView = {
            let imageView = UIImageView(frame: frame)

            imageView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
            imageView.contentMode = .center
            imageView.clipsToBounds = true

            return imageView
        }()

        super.init(frame: frame)

        contentView.addSubview(imageView)

        imageView.frame = contentView.bounds
    }

    required init(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // MARK: - Lifecycle Methods

    func configureCell(with URLString: String, placeholderImage: UIImage) {
        let size = imageView.frame.size

        imageView.af_setImage(
            withURL: URL(string: URLString)!,
            placeholderImage: placeholderImage,
            filter: AspectScaledToFillSizeWithRoundedCornersFilter(size: size, radius: 20.0),
            imageTransition: .crossDissolve(0.2)
        )
    }

    override func prepareForReuse() {
        super.prepareForReuse()

        imageView.af_cancelImageRequest()
        imageView.layer.removeAllAnimations()
        imageView.image = nil
    }
}

Cheers.