I’m able to reveal my problem with this straightforward instance.

I’m utilizing AsyncDisplayKit / Texture in my iOS app.

I’ve a ASTableNode which reveals attributed strings. These could have photos in them by way of NSTextAttachment. These photos will probably be from URLs which will probably be downloaded asynchronously. On this instance, for simplicity, I’m simply utilizing a picture from the Bundle. As soon as downloaded, the NSTextAttachment must replace its bounds to the proper side ratio of the particular picture.

The issue I’m going through is that regardless of me calling setNeedsLayout() and layoutIfNeeded() after updating the picture and bounds of the NSTextAttachment after getting the picture, the ASTextNode by no means updates to indicate the picture. I’m not certain what I’m lacking.

Code:

import UIKit
import AsyncDisplayKit

class ViewController: ASDKViewController<ASDisplayNode>, ASTableDataSource {

    let tableNode = ASTableNode()
    
    override init() {
      tremendous.init(node: tableNode)
      tableNode.dataSource = self
    }

    required init?(coder aDecoder: NSCoder) {
      fatalError()
    }

    func tableNode(_ tableNode: ASTableNode, numberOfRowsInSection part: Int) -> Int {
        return 1
    }
    
    func tableNode(_ tableNode: ASTableNode, nodeBlockForRowAt indexPath: IndexPath) -> ASCellNodeBlock {
        let row = indexPath.row
        return {
            let node = MyCellNode(index: row, earlier than: """
                                  Merchandise (row).
                                  Lorem Ipsum is just dummy textual content of the printing and typesetting trade. Lorem Ipsum has been the trade's commonplace dummy textual content ever for the reason that 1500s, when an unknown printer took a galley of sort and scrambled it to make a sort specimen e book.
                                  """,
            after: """
Opposite to widespread perception, Lorem Ipsum shouldn't be merely random textual content. It has roots in a bit of classical Latin literature from 45 BC, making it over 2000 years previous.
""")
            return node
        }
    }
}

class MyCellNode: ASCellNode {
    
    fileprivate var myTextNode = ASTextNode()
    
    init(index : Int, earlier than: String, after: String) {
        tremendous.init()
        debugName = "Row (index)"
        automaticallyManagesSubnodes = true
        automaticallyRelayoutOnSafeAreaChanges = true
        automaticallyRelayoutOnLayoutMarginsChanges = true
        let attributedText = NSMutableAttributedString(attributedString: (earlier than+"n").formattedText())
        
        let attachment = CustomAttachment(url: Bundle.most important.url(forResource: "check", withExtension: "png")!)
        attachment.bounds = CGRect(x: 0, y: 0, width: CGFLOAT_MIN, top: CGFLOAT_MIN)
        attachment.picture = UIImage()
        let attachmentAttributedString = NSMutableAttributedString(attachment: attachment)
        let fashion = NSMutableParagraphStyle()
        fashion.alignment = .middle
        attachmentAttributedString.addAttribute(.paragraphStyle, worth: fashion)
        
        attributedText.append(attachmentAttributedString)
        
        attributedText.append(("n"+after).formattedText())
        
        myTextNode.attributedText = attributedText
        
    }

    override func layoutSpecThatFits(_ constrainedSize: ASSizeRange) -> ASLayoutSpec {
        
        
        if let attributedText = myTextNode.attributedText {
                        
            attributedText.enumerateAttribute(NSAttributedString.Key.attachment, in: NSRange(location: 0, size: attributedText.size)) { a, vary, _ in
                if let attachment = a as? CustomAttachment {
                    print("attachment: (attachment.bounds)")
                }
            }
        }
        
        
        let paddingToUse = 10.0
        return ASInsetLayoutSpec(insets: UIEdgeInsets(high: paddingToUse, left: paddingToUse, backside: paddingToUse, proper: paddingToUse), baby: myTextNode)
    }

    override func structure() {
        tremendous.structure()
    }
    
    override func didEnterPreloadState() {
        tremendous.didEnterPreloadState()
        print("----- didEnterPreloadState: (String(describing: debugName))")
        
        if let attributedText = myTextNode.attributedText {
                        
            attributedText.enumerateAttribute(NSAttributedString.Key.attachment, in: NSRange(location: 0, size: attributedText.size)) { a, vary, _ in
                if let attachment = a as? CustomAttachment {
//                    print("attachment: (attachment.url)")
                    if let imageData = NSData(contentsOf: attachment.url), let img = UIImage(knowledge: imageData as Information) {
                        print("Measurement: (img.measurement)")
                        attachment.picture = img
                        attachment.bounds = CGRect(x: 0, y: 0, width: 200, top: 200)
                        setNeedsLayout()
                        layoutIfNeeded()
                    }
                }
            }
        }
    }
    
    override func didExitPreloadState() {
        tremendous.didExitPreloadState()
        print("----- didExitPreloadState: (String(describing: debugName))")
    }
}

extension String {
    func formattedText() -> NSAttributedString {
        return NSAttributedString(string: self, attributes: [NSAttributedString.Key.foregroundColor : UIColor.white,NSAttributedString.Key.font: UIFont.systemFont(ofSize: 20, weight: .regular)])
    }
}

extension NSMutableAttributedString {
    func addAttribute(_ title: NSAttributedString.Key, worth: Any) {
        addAttribute(title, worth: worth, vary: NSRange(location: 0, size: size))
    }

    func addAttributes(_ attrs: [NSAttributedString.Key : Any]) {
        addAttributes(attrs, vary: NSRange(location: 0, size: size))
    }
}

class CustomAttachment: NSTextAttachment {
    var url : URL
    
    public init(url: URL) {
        self.url = url
        tremendous.init(knowledge: nil, ofType: nil)
    }
      
    required init?(coder: NSCoder) {
        fatalError()
    }
}