examplesswift/powerofcombine

This example show how you can download image from services

Power Of Combine

This example show how you can download image from services

import Foundation
import UIKit
import Combine

struct JSONImages : Codable {
  let images: [String]
}

let url = URL(string: "https://applecodingacademy.com/testData/testImages.json")!

func getImage(url: URL) -> AnyPublisher<UIImage, Error> {
  URLSession.shared.dataTaskPublisher(for: url)
    .map {
      $0.data
  }
  .compactMap {
    UIImage(data: $0)
  }
  .mapError {
    $0 as Error
  }
  .eraseToAnyPublisher()
}

let publisher = URLSession.shared.dataTaskPublisher(for: url)
  .map { $0.data }
  .decode(type: JSONImages.self, decoder: JSONDecoder())
  .map { $0.images.first! }
  .map { URL(string: $0)! }
  .flatMap {
    getImage(url: $0)
}.eraseToAnyPublisher()

let subscriber = publisher.sink(receiveCompletion: { completion in
  switch completion {
  case .finished:
    print("Termino Correctamente")
  case .failure(let error):
    print("Ha ocurrido un Error: \(error)")
  }
}, receiveValue: { succes in
  print(succes)
  succes
})

Con otra API:

import Foundation
import Combine
import UIKit

// MARK: - Welcome
struct Welcome: Codable {
    let page, perPage, total, totalPages: Int
    let data: [Datum]
    let support: Support

    enum CodingKeys: String, CodingKey {
        case page
        case perPage = "per_page"
        case total
        case totalPages = "total_pages"
        case data, support
    }
}

// MARK: - Datum
struct Datum: Codable {
    let id: Int
    let email, firstName, lastName: String
    let avatar: String

    enum CodingKeys: String, CodingKey {
        case id, email
        case firstName = "first_name"
        case lastName = "last_name"
        case avatar
    }
}

// MARK: - Support
struct Support: Codable {
    let url: String
    let text: String
}

// MARK: - Codigo

let url = URL(string: "https://reqres.in/api/users?page=1")!

func getImage(url: URL) ->  AnyPublisher<UIImage, Error> {
    
  URLSession.shared
    .dataTaskPublisher(for: url)
    .map {
      $0.data
    }
    .compactMap {
      UIImage(data: $0)
    }
    .mapError {
      $0 as Error
    }
    .eraseToAnyPublisher()
}

let publisher = URLSession.shared
  .dataTaskPublisher(for: url)
  .map {
    $0.data
  }
  .decode(type: Welcome.self, decoder: JSONDecoder())
  .map {
    $0.data
  }
  .flatMap {
    getImage(url: URL(string: $0[4].avatar)!)
  }
  .eraseToAnyPublisher()

let subscribe = publisher.sink(receiveCompletion: { completion in
  switch completion {
  case .finished:
    print("Termino Correctamente")
  case .failure(let error):
   print("Ha ocurrido un Error \(error)")
  }
}, receiveValue: { value in
//  print(value.data[1])
  print(value)
  value
})