using api with operation queue dependencies

OperationQueue_WithApi.swift

import UIKit

// MARK: - SyncManager
struct SyncManager
{
    func GetRecordsInSync()
    {
        debugPrint("inside the GetRecordsInSync")
        
        let animalOperation = BlockOperation()
        animalOperation.addExecutionBlock {
            let animals = Animals()
            animals.getAnimals { (animalCollection) in
                animalCollection?.forEach({ (animal) in
                    debugPrint("name of animal = \(animal.name)")
                })
            }
        }
        
        let employeeOperation = BlockOperation()
        employeeOperation.addExecutionBlock {
            let emp = Employee()
            emp.getEmployee { (employeeCollection) in
                employeeCollection?.forEach({ (employee) in
                    debugPrint("employee name = \(employee.name)")
                })
            }
        }
        
        employeeOperation.addDependency(animalOperation)
        
        let operationQueue = OperationQueue()
        operationQueue.addOperation(animalOperation)
        operationQueue.addOperation(employeeOperation)
    }
}

// MARK: - Animals struct
struct Animals
{
    func getAnimals(handler:@escaping(_ result: [Animal]?)-> Void)
    {
        debugPrint("inside the getAnimals function")
        var urlRequest = URLRequest(url: URL(string: "https://api-dev-scus-demo.azurewebsites.net/api/Animal/GetAnimals")!)
        urlRequest.httpMethod = "get"
        
        debugPrint("going to call the http utility for animal request")
        HttpUtility.shared.getData(request: urlRequest, response: AnimalResponse.self) { (result) in
            if(result != nil)
            {
                debugPrint("got the animal response from api")
                handler(result?.data)
            }
        }
    }
}

// MARK: - Employee struct
struct Employee
{
    func getEmployee(handler:@escaping(_ result: [EmployeeData]?)-> Void)
    {
        debugPrint("inside the get employee function")
        
        var urlRequest = URLRequest(url: URL(string: "https://api-dev-scus-demo.azurewebsites.net/api/Employee/GetEmployee?Department=mobile&UserId=15")!)
        urlRequest.httpMethod = "get"
        
        debugPrint("going to call the http utility for employee request")
        
        HttpUtility.shared.getData(request: urlRequest, response: EmployeeResponse.self) { (result) in
            if(result != nil)
            {
                debugPrint("got the emloyee response from api")
                handler(result?.data)
            }
        }
    }
}

// MARK: - HttpUtility
struct HttpUtility
{
    static let shared = HttpUtility()
    private init(){}
    func getData<T:Decodable>(request: URLRequest, response: T.Type, handler:@escaping(_ result: T?)-> Void)
    {
        URLSession.shared.dataTask(with: request) { (data, httpUrlResponse, error) in
            if(error == nil && data != nil && data?.count != 0) {
                //let str = String(data: data!, encoding: .utf8)
                //debugPrint(str)
                do {
                    let result = try JSONDecoder().decode(response, from: data!)
                    handler(result)
                } catch  {
                    debugPrint(error.localizedDescription)
                }
                
            }}.resume()
    }
}

// MARK: - AnimalResponse
struct AnimalResponse : Decodable
{
    let errorMessage: String?
    let data: [Animal]?
}

// MARK: - Animal
struct Animal: Decodable {
    let name: String
    let image: String
}

// MARK: - Welcome
struct EmployeeResponse: Decodable {
    let errorMessage: String?
    let data: [EmployeeData]?
}

// MARK: - Datum
struct EmployeeData: Decodable {
    let name, email, id,joining: String
}

let syncManager = SyncManager()
syncManager.GetRecordsInSync()