工厂助手

工厂助手提供了用于创建 Hono 组件（如中间件）的有用函数。有时很难设置正确的 TypeScript 类型，但此助手可以帮助您做到这一点。

导入

import { Hono } from 'hono'
import { createFactory, createMiddleware } from 'hono/factory'

createFactory()

createFactory() 将创建一个 Factory 类的实例。

import { createFactory } from 'hono/factory'

const factory = createFactory()

您可以将您的 Env 类型作为泛型传递

type Env = {
  Variables: {
    foo: string
  }
}

const factory = createFactory<Env>()

createMiddleware()

createMiddleware() 是 factory.createMiddleware() 的简写。此函数将创建您的自定义中间件。

const messageMiddleware = createMiddleware(async (c, next) => {
  await next()
  c.res.headers.set('X-Message', 'Good morning!')
})

提示：如果您想获取一个类似 message 的参数，可以像下面这样将其创建一个函数。

const messageMiddleware = (message: string) => {
  return createMiddleware(async (c, next) => {
    await next()
    c.res.headers.set('X-Message', message)
  })
}

app.use(messageMiddleware('Good evening!'))

factory.createHandlers()

createHandlers() 有助于在不同于 app.get('/') 的位置定义处理程序。

import { createFactory } from 'hono/factory'
import { logger } from 'hono/logger'

// ...

const factory = createFactory()

const middleware = factory.createMiddleware(async (c, next) => {
  c.set('foo', 'bar')
  await next()
})

const handlers = factory.createHandlers(logger(), middleware, (c) => {
  return c.json(c.var.foo)
})

app.get('/api', ...handlers)

factory.createApp() 实验性

createApp() 有助于使用正确的类型创建 Hono 实例。如果您将此方法与 createFactory() 一起使用，则可以避免在 Env 类型定义中出现冗余。

如果您的应用程序是这样的，您必须在两个地方设置 Env

import { createMiddleware } from 'hono/factory'

type Env = {
  Variables: {
    myVar: string
  }
}

// 1. Set the `Env` to `new Hono()`
const app = new Hono<Env>()

// 2. Set the `Env` to `createMiddleware()`
const mw = createMiddleware<Env>(async (c, next) => {
  await next()
})

app.use(mw)

通过使用 createFactory() 和 createApp()，您只需在一个地方设置 Env。

import { createFactory } from 'hono/factory'

// ...

// Set the `Env` to `createFactory()`
const factory = createFactory<Env>()

const app = factory.createApp()

// factory also has `createMiddleware()`
const mw = factory.createMiddleware(async (c, next) => {
  await next()
})

createFactory() 可以接收 initApp 选项来初始化由 createApp() 创建的 app。以下是用该选项的示例。

// factory-with-db.ts
type Env = {
  Bindings: {
    MY_DB: D1Database
  }
  Variables: {
    db: DrizzleD1Database
  }
}

export default createFactory<Env>({
  initApp: (app) => {
    app.use(async (c, next) => {
      const db = drizzle(c.env.MY_DB)
      c.set('db', db)
      await next()
    })
  },
})

// crud.ts
import factoryWithDB from './factory-with-db'

const app = factoryWithDB.createApp()

app.post('/posts', (c) => {
  c.var.db.insert()
  // ...
})