Swift Vapor - 'Cannot invoke ' add' with an argument list of type...' 在 configure.swift 中出现错误

Question

我正在 YouTube 上制作 Paul Hudson 的电子商务教程。我在 configure.swift 中遇到以下错误:

import FluentSQLite
import Vapor
import Leaf // added
/// Called before your application initializes.
public func configure(_ config: inout Config, _ env: inout Environment, _ services: inout Services) throws {
    // Register providers first
    try services.register(FluentSQLiteProvider())

    // Register routes to the router
    let router = EngineRouter.default()
    try routes(router)
    services.register(router, as: Router.self)

    // Register middleware
    var middlewares = MiddlewareConfig() // Create _empty_ middleware config
    // middlewares.use(FileMiddleware.self) // Serves files from `Public/` directory
    middlewares.use(ErrorMiddleware.self) // Catches errors and converts to HTTP response
    services.register(middlewares)

    // Configure a SQLite database
    let sqlite = try SQLiteDatabase(storage: .memory)
    // Register the configured SQLite database to the database config.
    var databases = DatabasesConfig()
    databases.add(database: sqlite, as: .sqlite)
    services.register(databases)

    // Configure migrations
    var migrations = MigrationConfig()
    migrations.add(model: Todo.self, database: .sqlite)
    services.register(migrations)
    let leafProvider = LeafProvider()    // added
    try services.register(leafProvider)  // added
    config.prefer(LeafRenderer.self, for: ViewRenderer.self)// added
      // http://localhost:8080/ already in use so adding new server http://localhost:8080/ below -
    let serverConfigure = NIOServerConfig.default(hostname: "0.0.0.0", port: 9090)
    services.register(serverConfigure)

    let directoryConfig = DirectoryConfig.detect()
    services.register(directoryConfig)
    try services.register(FluentSQLiteProvider())
    var databaseConfig = DatabasesConfig()
    let db =    try SQLiteDatabase(storage: .file(path:   "\(directoryConfig.workDir)pizza.db"))
     databaseConfig.add(model: db, database: as .sqlite)
    /**
    The line just above shows errors - 
    errror 1 -> Cannot invoke 'add' with an argument list of type '(model:      
    SQLiteDatabase)'
    error 2 -> Expected expression in list of expressions 
    */       
    services.register(databaseConfig)
    var migrationConfig =  MigrationConfig()
    migrationConfig.add(model: pizza.self,  database: sqlite)
    /**
    The line just above shows error -> Cannot invoke 'add' with an argument list of type     '(model: pizza.Type, database: SQLiteDatabase)'
    */
    services.register(migrationConfig)
} 
// configure.swift ends here

我也在粘贴我的 Package.swift 代码以供引用 -

 // swift-tools-version:4.0

import PackageDescription

let package = Package(
name: "vv",
products: [
    .library(name: "vv", targets: ["App"]),
],
dependencies: [
    // 💧 A server-side Swift web framework.
    .package(url: "https://github.com/vapor/vapor.git", from: "3.0.0"),

    // 🔵 Swift ORM (queries, models, relations, etc) built on SQLite 3.
    .package(url: "https://github.com/vapor/fluent-sqlite.git", from: "3.0.0"),
.package(url: "https://github.com/vapor/leaf.git", from: "3.0.0"),
],
targets: [
    .target(name: "App", dependencies: ["Leaf", "Vapor","FluentSQLite"]),
 .target(name: "Run", dependencies: ["App"]),
    .testTarget(name: "AppTests", dependencies: ["App"])
]
)

比萨.swift文件 -

 import Foundation
 import Vapor
 import FluentSQLite

 struct pizza: Encodable, Content, Decodable, SQLiteModel {
     var id:  Int?
     var name: String
     var description: String
     var  price: Int
 }

我无法弄清楚上述错误的含义!谢谢。

routes.swift 文件 -

import Routing
import Vapor
import FluentSQLite

public func routes(_ router: Router) throws {
router.get { req -> Future <View> in
let Newyorker = Pizza(id: 5, name: "statinisland", description: "impracticaljokers", price: 55)
    let Traditional = Pizza(id: 5, name: "rome", description: "pope", price: 55)
    return try req.view().render("welcome",["pizza":[Newyorker,Traditional]])
}

 router.post(Pizza.self, at: "add") { req, pizza ->
     Future<Response> in
    return Pizza.save(on:req).map(to:Response.self) {Pizza
        in
        return req.redirect(to: "/")
    }
   }
/*Error - Type 'Pizza' has no member 'save'; did you mean 'name'?
 Replace 'save' with 'name' */  
 }

Answer 1

这是对我原始答案的重写，以解决所有问题:
configure.swift

不要定义 MigrationConfig() 的多个实例和 DatabaseConfig() .

将相关任务(例如添加模型)组合在一起将使您的代码更易于调试和维护。

您添加了 .sqlite 的两个实例数据库。

您省略了 .在 .sqlite当您添加 pizza 时模型。

因此，您的 configure.swift 的相关部分变为:

let directoryConfig = DirectoryConfig.detect()
services.register(directoryConfig)
let sqlite = try SQLiteDatabase(storage: .file(path:   "\(directoryConfig.workDir)pizza.db"))
// Register the configured SQLite database to the database config.
var databases = DatabasesConfig()
databases.add(database: sqlite, as: .sqlite)
services.register(databases)

var migrations = MigrationConfig()
migrations.add(model: Todo.self, database: .sqlite)
migrations.add(model: Pizza.self,  database: .sqlite)
services.register(migrations)

pizza.swift :

我更喜欢使用 final class而不是 struct因为它为您提供了更大的灵活性(例如在您的初始化程序中)。

您需要使其符合 Migration .

所以，最小 Pizza模型变为:

final class Pizza:SQLiteModel {
    var id:  Int?
    var name: String
    var description: String
    var  price: Int

    init(id: Int? = nil, name: String, desc:String, price:Int)
    {
        self.id = id
        self.description = desc
        self.name = name
        self.price = price
    }
 }

extension Pizza: Migration { }

为了完整起见，您的 configure.swift 变为:

import FluentSQLite
import Vapor
import Leaf // added
public func configure(_ config: inout Config, _ env: inout Environment, _ services: inout Services) throws {
    // Register providers first
    try services.register(FluentSQLiteProvider())

    // Register routes to the router
    let router = EngineRouter.default()
    try routes(router)
    services.register(router, as: Router.self)

    // Register middleware
    var middlewares = MiddlewareConfig() // Create _empty_ middleware config
    // middlewares.use(FileMiddleware.self) // Serves files from `Public/` directory
    middlewares.use(ErrorMiddleware.self) // Catches errors and converts to HTTP response
    services.register(middlewares)

    let directoryConfig = DirectoryConfig.detect()
    services.register(directoryConfig)
    let sqlite = try SQLiteDatabase(storage: .file(path:"\(directoryConfig.workDir)pizza.db"))
    var databases = DatabasesConfig()
    databases.add(database: sqlite, as: .sqlite)
    services.register(databases)

    var migrations = MigrationConfig()
    migrations.add(model: Todo.self, database: .sqlite)
    migrations.add(model: Pizza.self, database: .sqlite)
    services.register(migrations)

    let leafProvider = LeafProvider()    // added
    try services.register(leafProvider)  // added
    config.prefer(LeafRenderer.self, for: ViewRenderer.self)// added
    let serverConfigure = NIOServerConfig.default(hostname: "0.0.0.0", port: 9090)
    services.register(serverConfigure)
}