ProductController

gistfile1.swift

// ProductDelegate

import UIKit

protocol ProductDelegate: NSObjectProtocol {
  func didReceiveProduct(product: Product)
  func didReceiveProductImage(image: UIImage)
}

// ProductController

struct ProductController {
  let product: Product
  let productFetcher: ProductFetcher
  weak var productDelegate: ProductDelegate?
  
  init(product: Product, productDelegate: ProductDelegate, productFetcher: ProductFetcher = ProductClient()) {
    self.product = product
    self.productFetcher = productFetcher
    self.productDelegate = productDelegate
  }
  
  func fetchProductData() {
    productFetcher.fetchDataFor(product: product) { product in
      self.productDelegate?.didReceiveProduct(product)
    }
  }
  
  func fetchProductImage(imageUrl: String?) {
    if let url = imageUrl {
      productFetcher.fetchImageFor(url) { image in
        self.productDelegate?.didReceiveProductImage(image)
      }
    }
  }
}