在Swift中传递Web服务中的参数

Question

我正在学习Swift，我不知道如何使用Swift将参数发送到服务器。 在Objective-C中，我们可以使用"%@"作为占位符来完成此操作。 但是对于Swift应该怎么做，假设我有一个需要电子邮件和密码的登录网络服务。

现在我想知道我将如何将logintextfield和passwordtextfield文本发送到服务器，例如，

var bodyData = "email=logintextfield.text&password=passwordtextfield.text"

Answer 1

当创建包含用户输入的HTTP请求时，如果用户的输入中有任何保留字符，通常应该百分之一地逃避它，因此：

let login    = logintextfield.text?.addingPercentEncodingForURLQueryValue() ?? ""
let password = passwordtextfield.text?.addingPercentEncodingForURLQueryValue() ?? ""
let bodyData = "email=\(login)&password=\(password)"

注意，您真的想查看login和password是否nil。无论如何，逃逸百分比如下：

extension String {

    /// Percent escapes values to be added to a URL query as specified in RFC 3986
    ///
    /// This percent-escapes all characters besides the alphanumeric character set and "-", ".", "_", and "~".
    ///
    /// http://www.ietf.org/rfc/rfc3986.txt
    ///
    /// :returns: Returns percent-escaped string.

    func addingPercentEncodingForURLQueryValue() -> String? {
        let allowedCharacters = CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._~")

        return self.addingPercentEncoding(withAllowedCharacters: allowedCharacters)
    }

}

有关此扩展程序的其他详情，请参阅this answer。

---

如果您想看到使用上述内容的演示，请想象以下请求：

let keyData = "AIzaSyCRLa4LQZWNQBcjCYcIVYA45i9i8zfClqc"
let sensorInformation = false
let types = "building"
let radius = 1000000
let locationCoordinate = CLLocationCoordinate2D(latitude:40.748716, longitude: -73.985643)
let name = "Empire State Building, New York, NY"
let floors = 102
let now = Date()

let params:[String: Any] = [
    "key" : keyData,
    "sensor" : sensorInformation,
    "typesData" : types,
    "radius" : radius,
    "location" : locationCoordinate,
    "name" : name,
    "floors" : floors,
    "when" : now,
    "pi" : M_PI]

let url = URL(string: "http://some.web.site.com/inquiry")!
var request = URLRequest(url: url)
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.httpBody = params.dataFromHttpParameters()

let task = URLSession.shared.dataTask(with: request) { data, response, error in
    guard data != nil && error == nil else {
        print("error submitting request: \(error)")
        return
    }

    if let httpResponse = response as? HTTPURLResponse where httpResponse.statusCode != 200 {
        print("response was not 200: \(response)")
        return
    }

    // handle the data of the successful response here
}
task.resume()

我包含了许多未包含在您的示例中的参数，但仅仅是为了说明例程对各种参数类型的处理。

顺便提一下，上面使用我的datafromHttpParameters函数：

extension Dictionary {

    /// This creates a String representation of the supplied value.
    ///
    /// This converts NSDate objects to a RFC3339 formatted string, booleans to "true" or "false",
    /// and otherwise returns the default string representation.
    ///
    /// - parameter value: The value to be converted to a string
    ///
    /// - returns:         String representation

    private func httpStringRepresentation(_ value: Any) -> String {
        switch value {
        case let date as Date:
            return date.rfc3339String()
        case let coordinate as CLLocationCoordinate2D:
            return "\(coordinate.latitude),\(coordinate.longitude)"
        case let boolean as Bool:
            return boolean ? "true" : "false"
        default:
            return "\(value)"
        }
    }

    /// Build `Data` representation of HTTP parameter dictionary of keys and objects
    ///
    /// This percent escapes in compliance with RFC 3986
    ///
    /// http://www.ietf.org/rfc/rfc3986.txt
    ///
    /// :returns: String representation in the form of key1=value1&key2=value2 where the keys and values are percent escaped

    func dataFromHttpParameters() -> Data {
        let parameterArray = self.map { (key, value) -> String in
            let percentEscapedKey = (key as! String).addingPercentEncodingForURLQueryValue()!
            let percentEscapedValue = httpStringRepresentation(value).addingPercentEncodingForURLQueryValue()!
            return "\(percentEscapedKey)=\(percentEscapedValue)"
        }

        return parameterArray.joined(separator: "&").data(using: .utf8)!
    }

}

这里，因为我正在处理一组参数字符串，所以我使用join函数将它们连接起来，用&分隔，但这个想法是一样的。

随意自定义该功能以处理您可能传入的任何数据类型（例如，我通常不会CLLocationCoordinate2D，但您的示例包括一个，所以我想展示什么它可能看起来像）。但关键是，如果您提供包含用户输入的任何字段，请确保将其百分比转义。

仅供参考，这是我上面使用的rfc3339String函数。 （显然，如果你不需要传输日期，你就不需要这样做，但我为了更完整的解决方案而包括它。）

extension Date {

    /// Get RFC 3339/ISO 8601 string representation of the date.
    ///
    /// For more information, see:
    ///
    /// https://developer.apple.com/library/ios/qa/qa1480/_index.html
    ///
    /// - returns: Return RFC 3339 representation of date string

    func rfc3339String() -> String {
        let formatter = DateFormatter()

        formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSX"
        formatter.timeZone = TimeZone(secondsFromGMT: 0)
        formatter.locale = Locale(identifier: "en_US_POSIX")

        return formatter.string(from: self)
    }
}

要查看Swift 2的演绎，请参阅此答案的previous rendition。

Answer 2

可以通过在服务中传递所需的参数来完成，

var urlPath = NSString(format: "https://maps.googleapis.com/maps/api/place/search/json?key=AIzaSyCRLa4LQZWNQBcjCYcIVYA45i9i8zfClqc&sensor=false&types=restaurant&radius=100000&location=\(locationCoord)")

此处urlPath是包含网络服务的网址，locationCoord（作为最后一个参数）是网络服务的位置参数的运行时值。参数键，传感器，半径和类型是固定的。

Answer 3

我在登录按钮上调用json点击

@IBAction func loginClicked(sender : AnyObject){

var request = NSMutableURLRequest(URL: NSURL(string: kLoginURL)) // Here, kLogin contains the Login API.

  var session = NSURLSession.sharedSession()

    request.HTTPMethod = "POST"

    var err: NSError?
    request.HTTPBody = NSJSONSerialization.dataWithJSONObject(self.criteriaDic(), options: nil, error: &err) // This Line fills the web service with required parameters.
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")

    var task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
     //   println("Response: \(response)")
    var strData = NSString(data: data, encoding: NSUTF8StringEncoding)
    println("Body: \(strData)")       
    var err1: NSError?
    var json2 = NSJSONSerialization.JSONObjectWithData(strData.dataUsingEncoding(NSUTF8StringEncoding), options: .MutableLeaves, error:&err1 ) as NSDictionary

    println("json2 :\(json2)")

    if(err) {
        println(err!.localizedDescription)
    }
    else {
        var success = json2["success"] as? Int
        println("Succes: \(success)")
    }
    })

    task.resume()
}

在这里，我为参数创建了一个单独的字典。

var params = ["format":"json", "MobileType":"IOS","MIN":"f8d16d98ad12acdbbe1de647414495ec","UserName":emailTxtField.text,"PWD":passwordTxtField.text,"SigninVia":"SH"]as NSDictionary
     return params
     }

Answer 4

基于以上所述，我最终得到了这个，以便在Set-Cookie元素中获得一个令牌。

URLResponse的位置

<NSHTTPURLResponse: 0x17403ef20> { URL: http://bla.co.uk//auth/authenticate?email=bob@isp.eu&password=xcode } { status code: 200, headers {
    "Cache-Control" = "private, must-revalidate";
    Connection = "keep-alive";
    "Content-Type" = "application/json";
    Date = "Fri, 17 Feb 2017 10:51:41 GMT";
    Expires = "-1";
    Pragma = "no-cache";
    Server = nginx;
    "Set-Cookie" = "token=Cu4CmOaverylongstring0mCu4CmOpBGg; expires=Fri, 17-Feb-2017 20:51:41 GMT; Max-Age=36000; path=auth; httponly";
    "Transfer-Encoding" = Identity;
    "X-Powered-By" = "PHP/5.5.9-1ubuntu4.19, PleskLin";
} }



func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive response: URLResponse, completionHandler: @escaping (URLSession.ResponseDisposition) -> Void) {
    let httpResponse = response as! HTTPURLResponse
    let statusCode = httpResponse.statusCode

    if statusCode == 200 {
        let keyValues = httpResponse.allHeaderFields.map { (String(describing: $0.key).lowercased(), String(describing: $0.value)) }

        // Now filter the array, searching for your header-key, also lowercased
        if let myHeaderValue = keyValues.filter({ $0.0 == "Set-Cookie".lowercased() }).first {
            print(myHeaderValue.1)
            let cookies = myHeaderValue.1
            let cookieDict = cookies.components(separatedBy: ";")
            print("\(cookieDict)")
            let tokenEntryParameter = cookieDict.filter({$0 .contains("token")})
            let tokenEntry = tokenEntryParameter.first
            token = (tokenEntry?.components(separatedBy: "=").last)!
        }
    }
}