观察异步请求 [英] Observing Asynchronous Requests
问题描述
我对API进行了三个单独的调用.当所有三个调用完成时,我将汇总数据并使用它形成一个单独的模型对象.
I have three separate calls to APIs. When all three calls are complete, I am going to aggregate the data and use it to form a separate model object.
我认为我会使用属性观察器来完成此操作,但是我不知道如何实现.任何帮助或指导将不胜感激.
I figured I would use property observers to accomplish this but I have no idea how it would be implemented. Any help or guidance would be appreciated.
我创建了一个用于进行网络调用的模型对象,该模型将响应数据传递到转义的闭包中.这是解析数据的功能:
I have created a model object for making the network calls that passes the response data into an escaping closure. This is the function where the data is parsed:
func loadLibrary() {
// League Data Containers
var names = Dictionary<Int, String>() // API Call 1
var titles = Dictionary<Int, String>() // Call 1
var masteryLevels = Dictionary<Int, Int>() // 2
var masteryPoints = Dictionary<Int, Int>() // 2
// Champion Data Containers
var championRolesLibrary = Array<Dictionary<String,Array<Role>>>() // 3
var championWithRoles = Dictionary<String,Array<Role>>() // 3
var championRoles = Array<Role>() // 3
// Making Calls to the APIs
leagueAPI.downloadStaticData { data in
// API Call is made and data is parsed into containers
}
leagueAPI.downloadChampionMasteryData { data in
// API Call is made and data is parsed into containers
}
championAPI.downloadChampionRolesData { data in
// API Call is made and data is parsed into containers
}
// Once all three calls have completed and the data has been parsed into different containers, the data is all brought together to create a library of objects.
func aggregateData() {
// Take data from all the containers and use them in here.
// The issue is when to call this function.
}
}
推荐答案
一种简单的解决方法是嵌套所有三个请求:
A simple way to solve that is by nesting all three requests:
func loadLibrary() {
// League Data Containers
var names = Dictionary<Int, String>() // API Call 1
var titles = Dictionary<Int, String>() // Call 1
var masteryLevels = Dictionary<Int, Int>() // 2
var masteryPoints = Dictionary<Int, Int>() // 2
// Champion Data Containers
var championRolesLibrary = Array<Dictionary<String,Array<Role>>>() // 3
var championWithRoles = Dictionary<String,Array<Role>>() // 3
var championRoles = Array<Role>() // 3
// Making Calls to the APIs
leagueAPI.downloadStaticData { data in
// API Call is made and data is parsed into containers
leagueAPI.downloadChampionMasteryData { data2 in
// API Call is made and data is parsed into containers
championAPI.downloadChampionRolesData { data3 in
// API Call is made and data is parsed into containers// Once all three calls have completed and the data has been parsed into different containers, the data is all brought together to create a library of objects.
aggregateData() {
// Take data from all the containers and use them in here.
// The issue is when to call this function.
}
}
}
}
}
您也可以使用@ rmaddy所说的DispatchGroup来完成所需的操作,在这种情况下,您可以这样做:
You can also accomplish what you want by using DispatchGroup as said by @ rmaddy, in this case you would do this:
func loadLibrary() {
// League Data Containers
var names = Dictionary<Int, String>() // API Call 1
var titles = Dictionary<Int, String>() // Call 1
var masteryLevels = Dictionary<Int, Int>() // 2
var masteryPoints = Dictionary<Int, Int>() // 2
// Champion Data Containers
var championRolesLibrary = Array<Dictionary<String,Array<Role>>>() // 3
var championWithRoles = Dictionary<String,Array<Role>>() // 3
var championRoles = Array<Role>() // 3
// Create DispatchGroup
let dispatchGroup = DispatchGroup()
// Making Calls to the APIs
dispatchGroup.enter()
leagueAPI.downloadStaticData { data in
// API Call is made and data is parsed into containers
dispatchGroup.leave()
}
dispatchGroup.enter()
leagueAPI.downloadChampionMasteryData { data in
// API Call is made and data is parsed into containers
dispatchGroup.leave()
}
dispatchGroup.enter()
championAPI.downloadChampionRolesData { data in
// API Call is made and data is parsed into containers
dispatchGroup.leave()
}
// Once all three calls have completed and the data has been parsed into different containers, the data is all brought together to create a library of objects.
dispatchGroup.notify(queue: DispatchQueue.global(qos: .background)){
aggregateData() {
// Take data from all the containers and use them in here.
// The issue is when to call this function.
}
}
}
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