SDWebImageManager: Store image with transform

SDWebImageManagerExtension.swift

//
//  SDWebImageManager.swift
//  Backbone
//
//  Created by Winston Du on 1/8/20.
//

import Foundation
import SDWebImage

extension SDWebImageManager {
    // Largely a transpilation of relevant portion of SDWebImageManager.callTransformProcessForOperation
    func storeWithTransform(image: UIImage?, imageData: Data?, url: URL?, forKey key: String, transformer: SDImageTransformer, cacheType: SDImageCacheType = SDImageCacheType.all, cacheSerializer: SDWebImageCacheSerializer? = nil, completion: SDWebImageNoParamsBlock?) {

        if let image = image, let transformedImage =
            transformer.transformedImage(with: image, forKey: key) {
            let transformerKey: String = transformer.transformerKey;
            let cacheKey: String? = SDTransformedKeyForKey(key, transformerKey)
            let imageWasTransformed: Bool = transformedImage != image
            var cacheData: Data?;
            // pass nil if the image was transformed, so we can recalculate the data from the image
            if cacheSerializer != nil && (cacheType == .disk || cacheType == .all) {
                cacheData = cacheSerializer?.cacheData(with: transformedImage, originalData: imageWasTransformed ? nil : imageData, imageURL: url)
            } else {
                cacheData = (imageWasTransformed ? nil : imageData);
            }
            // keep the original image format and extended data
            // Image Metadata
            transformedImage.sd_isIncremental = image.sd_isIncremental;
            transformedImage.sd_imageLoopCount = image.sd_imageLoopCount;
            transformedImage.sd_imageFormat = image.sd_imageFormat;
            // Force Decode
            transformedImage.sd_isDecoded = image.sd_isDecoded;
            // Extended Cache Data
            transformedImage.sd_extendedObject = image.sd_extendedObject;
            self.imageCache.store(image, imageData: cacheData, forKey: cacheKey, cacheType: cacheType, completion: completion)
        }
    }
}