wingovers

Nesting ObservableObjects / Observing Repositories for SwiftUI View Models

Situation

A simple app has a few repository objects that own the in-memory instance of specific models and organize persistence appropriately. Its instantiated by a DI container and passed to view models.

Observation

SwiftUI views do not diff and update upon changes within the repo's model. The view model does not fire its objectWillChange publisher – even though the repository is marked as @Published.

LeeKahSeng

import Foundation

let jsonString = """
{
  "S001": {
    "firstName": "Tony",
    "lastName": "Stark"
  },
  "S002": {
    "firstName": "Peter",

dry1lud

There is a function .retry() in Combine that helps to retry a request. Although it is not enough just to call retry() to achieve retring logic. The retry() function does not do another request but it re-subscribes only to a publisher. To make another request the tryCatch() might be used. In the code below if the first call fails there are three attempts to retry (retry(3)):

import UIKit
import Combine
import PlaygroundSupport

enum CustomNetworkingError: Error {
    case invalidServerResponse
}