Swift 后台开发 -- 登录授权(User & Model)

2017-01-14 10:03:15来源:http://www.jianshu.com/p/25df9b538007作者:YxxxHao人点击

最近一周感觉特别忙,导致很多东西没有来得及总结,今天总结下如何通过 Vapor 中的 User 和 Model 来实现一个登录和授权功能。如果对 Vapor 环境搭建和添加 MySQL 数据库不太清楚的,可以看我前面写的文章。


先上效果图:



8215D380-4688-4C43-8122-F843E619D52B.png

首先们先在工程目录 -> Sources -> App -> Models 目录下创建 Users.swift:



9ADAFE18-C170-47BD-813E-00505B2CA029.png

在这里需要注意的是我创建文件后,在 Xcode 里面显示的是 Users.swift ,而不是图上的 Models/Users.swift,在 Xcode 里面编译不过,但是在命令行里编译就过了,功能也正常,只有把整个工程清空,然后再 build 后,构建出来的 Xcode 工程才显示 Models/Users.swift,在 Xcode 里面才能正常编译通过,这个问题的原因不详,可能是 Xcode 的原因,也可能是其它,知道的朋友希望能告诉下我。


然后我们创建一个继承 Vapor User 的 EBUser 类(如果类名为User时,实现User protocol 时会出现问题):


final class EBUser: User {
var id: Node?
var username: String
var nickname: String
var avatar: String
var password: String
var exists: Bool = false
init(node: Node, in context: Context) throws {
}
func makeNode(context: Context) throws -> Node {
}
static func prepare(_ database: Database) throws {
}
static func revert(_ database: Database) throws {
}
}

并实现必须实现的 protocol,其中:


var id: Node?

这个属性是必须提供的,他充当的是数据库表中的主键;


var exists: Bool = false

这个属性说明的是数据表是不存在的,Vapor是建议提供的,后续版本可能会强制必须提供。


其中的 init(node: Node, in context: Context) 和 func makeNode(context: Context) throws -> Node 格式是固定的了,如下:


init(node: Node, in context: Context) throws {
id = try node.extract("id")
username = try node.extract("username")
nickname = try node.extract("nickname")
avatar = try node.extract("avatar")
password = try node.extract("password")
}
func makeNode(context: Context) throws -> Node {
return try Node(node: [
"id": id,
"username": username,
"nickname": nickname,
"avatar": avatar,
"password": password
])
}

这里的参数名和数据表里面的字段是对应的。


这里重点说下 prepare 和 revert 两个方法,这两个方法一个是创建表的,一个是删除表的,内容格式如下:


static func prepare(_ database: Database) throws {
try database.create("ebusers") { users in
users.id()
users.string("username")
users.string("nickname")
users.string("avatar")
users.string("password")
}
}
static func revert(_ database: Database) throws {
try database.delete("ebusers")
}

这里需要注意的是,就是表名要在类名上加个s,如 ebusers,原因不详,可能是 bug, 要不使用时会报一个表名错误。prepare 在表还没有创建过的时候,执行工程就会自动执行并创建对应的表,revert 方法则需要通过配置 arguments 执行:



7CC0E09B-D8DF-42B2-AB99-7228849F834C.png

在这一部分内容中,User是和 Model 基本相同的,只是实现的协议不同罢了,而 User 中与 Model 最大不的同点就是 authenticate:


public protocol Authenticator {
static func authenticate(credentials: Credentials) throws -> User
static func register(credentials: Credentials) throws -> User
}
public protocol User: Entity, Account, Authenticator { }

Authenticator 协议有两个方法,一个是授权,一个是注册,然后在 EBUser 中实现这两个协议方法:


static func authenticate(credentials: Credentials) throws -> User {
var user: EBUser?
switch credentials {
// 通过密码和用户名校验
case let credentials as UsernamePassword:
let fetchedUser = try EBUser.query()
.filter("username", credentials.username)
.first()
if let password = fetchedUser?.password,
password != "",
(try? BCrypt.verify(password: credentials.password, matchesHash: password)) == true {
user = fetchedUser
}
// 这里可以添加其它方式校验
default:
throw UnsupportedCredentialsError()
}
if let user = user {
return user
} else {
throw IncorrectCredentialsError()
}
}
static func register(credentials: Credentials) throws -> Auth.User {
var user: EBUser
switch credentials {
case let credentials as UsernamePassword:
user = EBUser(credentials: credentials)
default:
throw UnsupportedCredentialsError()
}
if try EBUser.query().filter("username", user.username).first() == nil {
try user.save()
return user
} else {
throw AccountTakenError()
}
}

这里先不单独讲解这两个方法使用,结合 main.swift 中的接口内容来说,先看 main.swift 内容:


import Vapor
import VaporMySQL
import HTTP
import Auth
import Turnstile
import TurnstileCrypto
let drop = Droplet()
let auth = AuthMiddleware(user: EBUser.self)
drop.addConfigurable(middleware: auth, name: "auth")
let mysql = try VaporMySQL.Provider(config: drop.config)
drop.addProvider(mysql)
drop.get { request in
let user = try? request.user()
var dashboardView = try Node(node: [
"authenticated": user != nil,
"baseURL": request.baseURL
])
dashboardView["account"] = try user?.makeNode()
return try drop.view.make("index", dashboardView)
}
drop.get("login") { request in
return try drop.view.make("login")
}
drop.post("login") { request in
guard let username = request.data["username"]?.string,
let password = request.data["password"]?.string else {
return try drop.view.make("login", ["flash": "Missing username or password"])
}
let credentials = UsernamePassword(username: username, password: password)
do {
try request.auth.login(credentials)
return Response(redirect: "/")
} catch let e {
return try drop.view.make("login", ["flash": "Invalid username or password"])
}
}
drop.get("register") { request in
return try drop.view.make("register")
}
drop.post("register") { request in
guard let username = request.data["username"]?.string,
let password = request.data["password"]?.string else {
return try drop.view.make("register", ["flash": "Missing username or password"])
}
let credentials = UsernamePassword(username: username, password: password)
do {
try _ = EBUser.register(credentials: credentials)
try request.auth.login(credentials)
return Response(redirect: "/")
} catch let e as TurnstileError {
return try drop.view.make("register", Node(node: ["flash": e.description]))
}
}
drop.get("logout") { request in
request.subject.logout()
return Response(redirect: "/")
}

为了方便使用,我们对 Request 做以下的扩展:


extension Request {
var baseURL: String {
return uri.scheme + "://" + uri.host + (uri.port == nil ? "" : ":/(uri.port!)")
}
var subject: Subject {
return storage["subject"] as! Subject
}
func user() throws -> User {
guard let user = try auth.user() as? EBUser else {
throw Abort.custom(status: .badRequest, message: "Invalid user type.")
}
return user
}
}

在使用 User 的 auth 功能时,我们需要把 AuthMiddleware 添加到 drop 里面:


let auth = AuthMiddleware(user: EBUser.self)
drop.preparations = [EBUser.self, Course.self]

这里添加 MySQL 的配置是时是直接从 config 里面读取:


let mysql = try VaporMySQL.Provider(config: drop.config)

使用这种方法时,我们需要在工程目录 -> Sources -> Config 目录下添加一个 mysql.json 文件,文件内容格式如下:



3924F5F0-8AA6-4F4C-9FDF-531B084217C1.png

这里也是和上篇中 MySQL 的配置的不同点。


我们看首页的请求实现方法:


drop.get { request in
let user = try? request.user()
var dashboardView = try Node(node: [
"authenticated": user != nil,
"baseURL": request.baseURL
])
dashboardView["account"] = try user?.makeNode()
return try drop.view.make("index", dashboardView)
}

我们首先会获取 request 里的 auth 的 user 对象(这里用到了上面提及的request的扩展方法user()和baseURL属性),如果在请求中没有获取的 atuh 的 user,证明用户还没有登录,我们则把一个名为 authenticated 的属性设置为 flase 传到页面, 这里的页面都使用了 leaf 语言来编写,leaf 的基本语法可以看官网介绍。


在登录功能中,这里一共写了三个页面, 首页(index.leaf)、登录页(login.leaf)、注册页(register.leaf):



378F0D2C-FC61-494C-B586-D3A1239C400F.png

index.leaf 内容:


#extend("base")
#export("body") {
#if(authenticated) {
<h3>Hi! #(account.username)!</h3>
}
##else() {
<h3>Hi! Sign up today!</h3>
#raw() {
["name": "EBer"]
Hello, /(name)!
}
}
}

login.leaf 内容:


#extend("base")
#export("body") {
<h1>Login</h1>
<form action="/login" method="POST">
<div>
<label for="username">Username</label>
<input type="text" name="username" placeholder="Username">
</div>
<div>
<label for="password">Password</label>
<input type="password" name="password" placeholder="Password">
</div>
<input type="hidden" name="_csrf" value="{{csrfToken}}">
<button type="submit">Login</button>
</form>
<p>Not a user of Exam Bank? <a href="/register">Register Today!</a></p>
}

register.leaf 内容:


#extend("base")
#export("body") {
<h1>Register</h1>
<form action="/register" method="POST">
<div>
<label for="username">Username</label>
<input type="text" name="username" placeholder="Username">
</div>
<div>
<label for="password">Password</label>
<input type="password" name="password" placeholder="Password">
</div>
<input type="hidden" name="_csrf" value="{{csrfToken}}">
<button type="submit">Register</button>
</form>
}

base.leaf 内容:


<html>
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<link href="/styles/app.css" rel="stylesheet">
<script type="text/javascript" charset="utf-8" src="/styles/app.js"></script>
<title>Exam Bank</title>
</head>
<body>
<div>
<div>
<nav>
<ul>
#if(authenticated) {
<li role="presentation"><a href="/logout">Logout</a></li>
}
##else() {
<li role="presentation"><a href="/login">Login</a></li>
}
</ul>
</nav>
<h3><a href="/">Exam Bank</a></h3>
</div>
#if(flash) {
<div role="alert">
<span aria-hidden="true"></span>
<span>Error:</span>
#(flash)
</div>
}
#import("body")
</div>
</body>
</html>

来看注册的方法:


drop.post("register") { request in
guard let username = request.data["username"]?.string,
let password = request.data["password"]?.string else {
return try drop.view.make("register", ["flash": "Missing username or password"])
}
let credentials = UsernamePassword(username: username, password: password)
do {
try _ = EBUser.register(credentials: credentials)
try request.auth.login(credentials)
return Response(redirect: "/")
} catch let e as TurnstileError {
return try drop.view.make("register", Node(node: ["flash": e.description]))
}
}

post 请求中应该传username 和 password 两个参数过来,再把这两个参数转为用户名密码证书:


let credentials = UsernamePassword(username: username, password: password)

然后调用 EBUser.register(credentials: credentials) 对该证书进行注册,然后我们执行request.auth.login(credentials) 方法。


注意,在执行 login(credentials) 方法时,会触发 EBUser 里的 func authenticate(credentials: Credentials) throws -> User 方法来进行授权判断,判断证书是否已经注册了,如果没有注册则返回相关的错误信息。


再看登录请求的实现:


drop.post("login") { request in
guard let username = request.data["username"]?.string,
let password = request.data["password"]?.string else {
return try drop.view.make("login", ["flash": "Missing username or password"])
}
let credentials = UsernamePassword(username: username, password: password)
do {
try request.auth.login(credentials)
return Response(redirect: "/")
} catch let e {
return try drop.view.make("login", ["flash": "Invalid username or password"])
}
}

注册请求中已经包含了登录,这里就不重复了。需要理解的就是 request.auth.login(credentials) 方法会触发 authenticate。


这里, 基本就说完了登录的全功能了,我们简单说下 Model 的功能,Model 和 User 很相似:


public protocol Model: Entity, JSONRepresentable, StringInitializable, ResponseRepresentable { }
public protocol User: Entity, Account, Authenticator { }

它们都实现了 Entity 协议, 在上面说授权相关的内容前,说的内容主要都是 Entity 协议上的东西.


这里主要说的是, Entity 协议上封装一些基本的 sql 查询方法,如:


let fetchedUser = try EBUser.query()
.filter("username", credentials.username)
.first()

这里就不详细说这个了,详细直接查看官网说明。


本文就写到这里,因为最近比较忙,所以更新会不定期,欢迎关注~~~


最后附上 EBUser 的完整代码:


import Foundation
import Vapor
import Auth
import HTTP
import Fluent
import Turnstile
import TurnstileCrypto
enum Error: Swift.Error {
case userNotFound
case registerNotSupported
case unsupportedCredentials
}
final class EBUser: User {
var id: Node?
var username: String
var nickname: String
var avatar: String
var password: String
var exists: Bool = false
init(username: String, nickname: String, avatar: String, password: String) {
self.username = username
self.nickname = nickname
self.avatar = avatar
self.password = BCrypt.hash(password: password)
}
init(credentials: UsernamePassword) {
self.username = credentials.username
self.password = BCrypt.hash(password: credentials.password)
self.nickname = ""
self.avatar = ""
}
init(node: Node, in context: Context) throws {
id = try node.extract("id")
username = try node.extract("username")
nickname = try node.extract("nickname")
avatar = try node.extract("avatar")
password = try node.extract("password")
}
func makeNode(context: Context) throws -> Node {
return try Node(node: [
"id": id,
"username": username,
"nickname": nickname,
"avatar": avatar,
"password": password
])
}
static func prepare(_ database: Database) throws {
try database.create("ebusers") { users in
users.id()
users.string("username")
users.string("nickname")
users.string("avatar")
users.string("password")
}
}
static func revert(_ database: Database) throws {
try database.delete("ebusers")
}
static func authenticate(credentials: Credentials) throws -> User {
var user: EBUser?
switch credentials {
case let credentials as UsernamePassword:
let fetchedUser = try EBUser.query()
.filter("username", credentials.username)
.first()
if let password = fetchedUser?.password,
password != "",
(try? BCrypt.verify(password: credentials.password, matchesHash: password)) == true {
user = fetchedUser
}
default:
throw UnsupportedCredentialsError()
}
if let user = user {
return user
} else {
throw IncorrectCredentialsError()
}
}
static func register(credentials: Credentials) throws -> Auth.User {
var user: EBUser
switch credentials {
case let credentials as UsernamePassword:
user = EBUser(credentials: credentials)
default:
throw UnsupportedCredentialsError()
}
if try EBUser.query().filter("username", user.username).first() == nil {
try user.save()
return user
} else {
throw AccountTakenError()
}
}
}



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