Использование убегающих замыканий

escaping_closure_usage.swift

import Foundation

class ViewController {
    
    let dataManager = DataManager()
    
    func viewDidLoad() {
        prepareContent()
    }
    
    private func prepareContent() {
        // ... loading
        dataManager.getData(completion: processingPost(_:))
    }
    
    private func prepareContent2() {
        // ... loading
        dataManager.getData { posts in
            posts.forEach { post in
                print(post)
                // ... make viewModels
                // ... hide loader
                // ... tableView.reloadData
            }
        }
    }
    
    func processingPost(_ posts: [Post]) {
        posts.forEach { post in
            print(post)
            // ... make viewModels
            // ... hide loader
            // ... tableView.reloadData
        }
    }
}

class DataManager {
    
    func getData(completion: @escaping((_ posts: [Post]) -> Void)) {
        sleep(3)
        // ... decode
        // ... cache
        completion([.init(), .init(), .init()])
    }
}

struct Post { }

let vc = ViewController()
vc.viewDidLoad()