Creating an Authorization Plugin(創(chuàng)建一個(gè)授權(quán)插件)

API請(qǐng)求通過JWT或者另外類型的訪問令牌來授權(quán)是相當(dāng)常見的。在這個(gè)例子中我們將創(chuàng)建一個(gè)插件用來把jwt添加到請(qǐng)求中。首先，讓我們來看下這個(gè)例子,如何通過插件把jwt添加到一個(gè)請(qǐng)求中.

struct AuthPlugin: PluginType {
  let token: String

  func prepare(_ request: URLRequest, target: TargetType) -> URLRequest {
    var request = request
    request.addValue("Bearer " + token, forHTTPHeaderField: "Authorization")
    return request
  }
}

let provider = MoyaProvider<Target>(plugins: [AuthPlugin(token: "eyeAm.AJsoN.weBTOKen")])

現(xiàn)在我們來看下更加復(fù)雜的例子，當(dāng)我們創(chuàng)建插件時(shí)我們可能還沒有訪問到j(luò)wt，或者不是所有的請(qǐng)求都需要簽名(ps：即攜帶認(rèn)證). 我們可以通過擴(kuò)展TargetType協(xié)議來提供是否需要授權(quán)的信息并且使用閉包來提供一個(gè)令牌。這樣完成這個(gè)功能。

class TokenSource {
  var token: String?
  init() { }
}

protocol AuthorizedTargetType: TargetType {
  var needsAuth: Bool { get }
}

struct AuthPlugin: PluginType {
  let tokenClosure: () -> String?

  func prepare(_ request: URLRequest, target: TargetType) -> URLRequest {
    guard
      let token = tokenClosure(),
      let target = target as? AuthorizedTargetType,
      target.needsAuth
    else {
      return request
    }

    var request = request
    request.addValue("Bearer " + token, forHTTPHeaderField: "Authorization")
    return request
  }
}

let source = TokenSource()
let provider = MoyaProvider<Target>(
  plugins: [
    AuthPlugin(tokenClosure: { return source.token })
  ]
)

source.token = "eyeAm.AJsoN.weBTOKen"

總結(jié) 這小節(jié)的核心:

1. 如何自定義授權(quán)插件,及復(fù)雜的授權(quán)插件