好吧，我要疯了...
我正在使用Alamofire 4.x（Swift 3和XCode 8.1）。我需要从需要身份验证的站点获取并解析几个html请求（不幸的是，没有json API）。然后，用Fuzi解析HTML，此过程可能需要一些时间，因此我计划使用ProgressHUD（准确地说是PKHUD）让用户知道发生了什么。我还需要获取一些不在身份验证后面的html。
我创建了一个结构和函数来处理整个网络过程并解析数据。
我设法执行了请求并获取了我需要的数据，但似乎无法弄清楚如何在正确的时间进行HUD更新。
到目前为止，这是我的代码：
import Alamofire
import Fuzi
import PKHUD
struct MyMSCProvider {
static let baseUrl = "http://mastersswimming.ca"
//I tried with or without a custom queue - same result
static let processingQueue = DispatchQueue(label: "com.colddiver.processing-queue", qos: .utility)
static func fetchData(data: MscRequest) {
if data.profile || data.log {
//Authenticate first!
HUD.show(.labeledProgress(title: "Authenticating", subtitle: ""))
let requestUrl = "\(baseUrl)/MyMscPage.jsp"
let parameters = ["locale": "en", "username": data.user.username, "password": data.user.password]
Alamofire.request(requestUrl, method: .post, parameters: parameters).responseData(
queue: processingQueue,
completionHandler:
{ response in
// Now on the processingQueue you created earlier.
print("THREAD: \(Thread.current) is main thread: \(Thread.isMainThread)")
switch response.result {
case .success:
if data.profile {
DispatchQueue.main.async {
HUD.show(.labeledProgress(title: "Getting Profile", subtitle: ""))
}
let userProfile = parseProfile(data: response.data!, user: data.user)
print(userProfile)
}
if data.log {
DispatchQueue.main.async {
HUD.show(.labeledProgress(title: "Getting Log", subtitle: ""))
}
fetchLog()
}
if data.records {
DispatchQueue.main.async {
HUD.show(.labeledProgress(title: "Getting Records", subtitle: ""))
}
fetchRecords(recordsToFetch: data.recordsToFetch)
}
if data.times {
DispatchQueue.main.async {
HUD.show(.labeledProgress(title: "Getting Times", subtitle: ""))
}
print("Fetching times is not implemented yet")
}
DispatchQueue.main.async {
HUD.flash(.success)
}
case .failure(let error):
HUD.flash(.error)
print("Alamofire request failed")
print(error)
}
}
)
} else {
//Just fetch - no need to authenticate first
if data.records {
DispatchQueue.main.async {
HUD.show(.labeledProgress(title: "Getting Records", subtitle: ""))
}
fetchRecords(recordsToFetch: data.recordsToFetch)
}
if data.times {
print("Fetching times is not implemented yet")
}
DispatchQueue.main.async {
HUD.flash(.success)
}
}
}
static func fetchRecords(recordsToFetch: RecordsToFetch) {
for province in recordsToFetch.provinces {
for ageGroup in recordsToFetch.ageGroups {
for gender in recordsToFetch.genders {
DispatchQueue.main.async {
HUD.show(.labeledProgress(title: "Getting Records", subtitle: "\(province) - \(gender+Helpers.getAgeGroupFromAge(age: Int(ageGroup)!))"))
}
let requestUrl = "\(baseUrl)/Records.jsp"
let parameters = ["locale": "en", "province": province, "age": ageGroup, "gender": gender, "course": "*"]
Alamofire.request(requestUrl, method: .post, parameters: parameters).responseData(
queue: processingQueue,
completionHandler: { response in
switch response.result {
case .success:
let recordArray = parseRecords(data: response.data!, province: province, ageGroup: ageGroup, gender: gender)
case .failure(let error):
DispatchQueue.main.async {
HUD.flash(.failure)
}
print("Alamofire request failed")
print(error)
}
}
)
}
}
}
}
static func fetchLog() {
let requestUrl = "\(baseUrl)/ViewLog.jsp"
Alamofire.request(requestUrl).responseData(
queue: processingQueue,
completionHandler: { response in
switch response.result {
case .success:
let log = parseLog(data: response.data!)
case .failure(let error):
DispatchQueue.main.async {
HUD.flash(.failure)
}
print("Alamofire request failed")
}
}
)
}
// MARK: - Convenience structs
struct MscRequest {
let profile: Bool
let log: Bool
let times: Bool
let records: Bool
let recordsToFetch: RecordsToFetch
let user: MscUser
let parentView: UITableViewController
}
在这种设置下，我将在TableViewController中设置一个MscRequest并启动一系列的请求，如下所示：
let myData = MscRequest.init(
profile: true,
log: true,
times: false,
records: true,
recordsToFetch: RecordsToFetch.init(
provinces: ["NB", "CA"],
ageGroups: ["20", "25", "30", "35", "40"],
genders: ["M", "F"]),
user: MscUser.init(
username: "SomeUserName",
password: "SomePassword"),
parentView: self
)
MyMSCProvider.fetchData(data: myData)
使用此设置，所有HUD更新将同时（在主线程上）完成，并在后台获取和解析仍在进行时最终被关闭。不完全是我想要的...
我尝试了各种迭代（有或没有自定义队列），也尝试了直接来自Alamofire手册的HTML请求代码（省略了completionHandler部分），但仍然得到了相同的结果...
我也看过了Grand Central Dispatch教程（例如本教程：http : //www.appcoda.com/grand-central-dispatch/），但我还没有弄清楚在使用Alamofire时如何应用信息。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。
值得注意的是，我当时通过手动NSURLRequests在Objective-C中完成了这项工作。我正在将该旧应用程序更新为Swift 3，并认为我应该尝试一下Alamofire。
不禁会觉得我缺少明显的东西...有什么提示吗？
好的，我找到了一种使用DispatchGroup进行操作的方法（Swift 3，Alamofire 4.x）
func fetchData() {
let requestGroup = DispatchGroup()
//Need as many of these statements as you have Alamofire.requests
requestGroup.enter()
requestGroup.enter()
requestGroup.enter()
Alamofire.request("http://httpbin.org/get").responseData { response in
print("DEBUG: FIRST Request")
requestGroup.leave()
}
Alamofire.request("http://httpbin.org/get").responseData { response in
print("DEBUG: SECOND Request")
requestGroup.leave()
}
Alamofire.request("http://httpbin.org/get").responseData { response in
print("DEBUG: THIRD Request")
requestGroup.leave()
}
//This only gets executed once all the above are done
requestGroup.notify(queue: DispatchQueue.main, execute: {
// Hide HUD, refresh data, etc.
print("DEBUG: all Done")
})
}
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