TanStack Router 的路由器上下文是一个非常强大的工具,可用于依赖注入等多种用途。顾名思义,路由器上下文通过路由器传递并向下传递到每个匹配的路由。在层级结构中的每个路由,上下文都可以被修改或添加。以下是一些您可能实际使用路由器上下文的方法:
这些只是路由器上下文的建议用法。您可以根据需要使用它!
像所有其他功能一样,根路由器上下文是严格类型化的。此类型可以通过任何路由的 beforeLoad 选项进行增强,因为它会合并到路由匹配树中。要约束根路由器上下文的类型,您必须使用 createRootRouteWithContext<YourContextTypeHere>()(routeOptions) 函数来创建新的路由器上下文,而不是使用 createRootRoute() 函数来创建根路由。以下是一个示例:
import {
createRootRouteWithContext,
createRouter,
} from '@tanstack/react-router'
interface MyRouterContext {
user: User
}
// Use the routerContext to create your root route
const rootRoute = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
const routeTree = rootRoute.addChildren([
// ...
])
// Use the routerContext to create your router
const router = createRouter({
routeTree,
})
import {
createRootRouteWithContext,
createRouter,
} from '@tanstack/react-router'
interface MyRouterContext {
user: User
}
// Use the routerContext to create your root route
const rootRoute = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
const routeTree = rootRoute.addChildren([
// ...
])
// Use the routerContext to create your router
const router = createRouter({
routeTree,
})
路由器上下文在实例化时传递给路由器。您可以通过 context 选项将初始路由器上下文传递给路由器。
提示
如果您的上下文有任何必需属性,如果未在初始路由器上下文中传递它们,您将看到 TypeScript 错误。如果您所有上下文属性都是可选的,您将不会看到 TypeScript 错误,并且传递上下文将是可选的。如果您不传递路由器上下文,它将默认为 {}。
import { createRouter } from '@tanstack/react-router'
// Use the routerContext you created to create your router
const router = createRouter({
routeTree,
context: {
user: {
id: '123',
name: 'John Doe',
},
},
})
import { createRouter } from '@tanstack/react-router'
// Use the routerContext you created to create your router
const router = createRouter({
routeTree,
context: {
user: {
id: '123',
name: 'John Doe',
},
},
})
如果您需要使您传递给路由器的上下文状态失效,可以调用 invalidate 方法,告诉路由器重新计算上下文。当您需要更新上下文状态并让路由器重新计算所有路由的上下文时,这非常有用。
function useAuth() {
const router = useRouter()
const [user, setUser] = useState<User | null>(null)
useEffect(() => {
const unsubscribe = auth.onAuthStateChanged((user) => {
setUser(user)
router.invalidate()
})
return unsubscribe
}, [])
return user
}
function useAuth() {
const router = useRouter()
const [user, setUser] = useState<User | null>(null)
useEffect(() => {
const unsubscribe = auth.onAuthStateChanged((user) => {
setUser(user)
router.invalidate()
})
return unsubscribe
}, [])
return user
}
定义路由器上下文类型后,您可以在路由定义中使用它
// src/routes/todos.tsx
export const Route = createFileRoute('/todos')({
component: Todos,
loader: ({ context }) => fetchTodosByUserId(context.user.id),
})
// src/routes/todos.tsx
export const Route = createFileRoute('/todos')({
component: Todos,
loader: ({ context }) => fetchTodosByUserId(context.user.id),
})
您甚至可以注入数据获取和突变实现本身!事实上,这是强烈推荐的 😜
让我们用一个简单的函数来尝试获取一些待办事项
const fetchTodosByUserId = async ({ userId }) => {
const response = await fetch(`/api/todos?userId=${userId}`)
const data = await response.json()
return data
}
const router = createRouter({
routeTree: rootRoute,
context: {
userId: '123',
fetchTodosByUserId,
},
})
const fetchTodosByUserId = async ({ userId }) => {
const response = await fetch(`/api/todos?userId=${userId}`)
const data = await response.json()
return data
}
const router = createRouter({
routeTree: rootRoute,
context: {
userId: '123',
fetchTodosByUserId,
},
})
然后,在您的路由中
// src/routes/todos.tsx
export const Route = createFileRoute('/todos')({
component: Todos,
loader: ({ context }) => context.fetchTodosByUserId(context.userId),
})
// src/routes/todos.tsx
export const Route = createFileRoute('/todos')({
component: Todos,
loader: ({ context }) => context.fetchTodosByUserId(context.userId),
})
import {
createRootRouteWithContext,
createRouter,
} from '@tanstack/react-router'
interface MyRouterContext {
queryClient: QueryClient
}
const rootRoute = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
const queryClient = new QueryClient()
const router = createRouter({
routeTree: rootRoute,
context: {
queryClient,
},
})
import {
createRootRouteWithContext,
createRouter,
} from '@tanstack/react-router'
interface MyRouterContext {
queryClient: QueryClient
}
const rootRoute = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
const queryClient = new QueryClient()
const router = createRouter({
routeTree: rootRoute,
context: {
queryClient,
},
})
然后,在您的路由中
// src/routes/todos.tsx
export const Route = createFileRoute('/todos')({
component: Todos,
loader: async ({ context }) => {
await context.queryClient.ensureQueryData({
queryKey: ['todos', { userId: user.id }],
queryFn: fetchTodos,
})
},
})
// src/routes/todos.tsx
export const Route = createFileRoute('/todos')({
component: Todos,
loader: async ({ context }) => {
await context.queryClient.ensureQueryData({
queryKey: ['todos', { userId: user.id }],
queryFn: fetchTodos,
})
},
})
当尝试在路由的 beforeLoad 或 loader 函数中使用 React Context 或 Hooks 时,重要的是要记住 React 的 Hooks 规则。您不能在非 React 函数中使用 hooks,因此不能在您的 beforeLoad 或 loader 函数中使用 hooks。
那么,我们如何在路由的 beforeLoad 或 loader 函数中使用 React Context 或 Hooks 呢?我们可以使用路由器上下文将 React Context 或 Hooks 传递给路由的 beforeLoad 或 loader 函数。
让我们看一个设置示例,我们将 useNetworkStrength hook 传递给路由的 loader 函数
// First, make sure the context for the root route is typed
import { createRootRouteWithContext } from '@tanstack/react-router'
import { useNetworkStrength } from '@/hooks/useNetworkStrength'
interface MyRouterContext {
networkStrength: ReturnType<typeof useNetworkStrength>
}
export const Route = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
// First, make sure the context for the root route is typed
import { createRootRouteWithContext } from '@tanstack/react-router'
import { useNetworkStrength } from '@/hooks/useNetworkStrength'
interface MyRouterContext {
networkStrength: ReturnType<typeof useNetworkStrength>
}
export const Route = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
在此示例中,我们将在渲染路由器之前使用 <RouterProvider /> 实例化 hook。这样,hook 将在 React 环境中调用,从而遵循 Hooks 规则。
import { createRouter } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'
export const router = createRouter({
routeTree,
context: {
networkStrength: undefined!, // We'll set this in React-land
},
})
import { createRouter } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'
export const router = createRouter({
routeTree,
context: {
networkStrength: undefined!, // We'll set this in React-land
},
})
import { RouterProvider } from '@tanstack/react-router'
import { router } from './router'
import { useNetworkStrength } from '@/hooks/useNetworkStrength'
function App() {
const networkStrength = useNetworkStrength()
// Inject the returned value from the hook into the router context
return <RouterProvider router={router} context={{ networkStrength }} />
}
// ...
import { RouterProvider } from '@tanstack/react-router'
import { router } from './router'
import { useNetworkStrength } from '@/hooks/useNetworkStrength'
function App() {
const networkStrength = useNetworkStrength()
// Inject the returned value from the hook into the router context
return <RouterProvider router={router} context={{ networkStrength }} />
}
// ...
所以,现在在路由的 loader 函数中,我们可以从路由器上下文访问 networkStrength hook
import { createFileRoute } from '@tanstack/react-router'
export const Route = createFileRoute('/posts')({
component: Posts,
loader: ({ context }) => {
if (context.networkStrength === 'STRONG') {
// Do something
}
},
})
import { createFileRoute } from '@tanstack/react-router'
export const Route = createFileRoute('/posts')({
component: Posts,
loader: ({ context }) => {
if (context.networkStrength === 'STRONG') {
// Do something
}
},
})
路由器上下文向下传递路由树并在每个路由处合并。这意味着您可以在每个路由处修改上下文,并且这些修改将对所有子路由可用。以下是一个示例:
import { createRootRouteWithContext } from '@tanstack/react-router'
interface MyRouterContext {
foo: boolean
}
export const Route = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
import { createRootRouteWithContext } from '@tanstack/react-router'
interface MyRouterContext {
foo: boolean
}
export const Route = createRootRouteWithContext<MyRouterContext>()({
component: App,
})
import { createRouter } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'
const router = createRouter({
routeTree,
context: {
foo: true,
},
})
import { createRouter } from '@tanstack/react-router'
import { routeTree } from './routeTree.gen'
const router = createRouter({
routeTree,
context: {
foo: true,
},
})
import { createFileRoute } from '@tanstack/react-router'
export const Route = createFileRoute('/todos')({
component: Todos,
beforeLoad: () => {
return {
bar: true,
}
},
loader: ({ context }) => {
context.foo // true
context.bar // true
},
})
import { createFileRoute } from '@tanstack/react-router'
export const Route = createFileRoute('/todos')({
component: Todos,
beforeLoad: () => {
return {
bar: true,
}
},
loader: ({ context }) => {
context.foo // true
context.bar // true
},
})
上下文,特别是独立的路由 context 对象,使得累积和处理所有匹配路由的路由上下文对象变得轻而易举。以下是一个示例,我们使用所有匹配路由上下文来生成面包屑导航:
// src/routes/__root.tsx
export const Route = createRootRoute({
component: () => {
const matches = useRouterState({ select: (s) => s.matches })
const breadcrumbs = matches
.filter((match) => match.context.getTitle)
.map(({ pathname, context }) => {
return {
title: context.getTitle(),
path: pathname,
}
})
// ...
},
})
// src/routes/__root.tsx
export const Route = createRootRoute({
component: () => {
const matches = useRouterState({ select: (s) => s.matches })
const breadcrumbs = matches
.filter((match) => match.context.getTitle)
.map(({ pathname, context }) => {
return {
title: context.getTitle(),
path: pathname,
}
})
// ...
},
})
使用相同的路由上下文,我们还可以为页面的 <head> 生成标题标签
// src/routes/__root.tsx
export const Route = createRootRoute({
component: () => {
const matches = useRouterState({ select: (s) => s.matches })
const matchWithTitle = [...matches]
.reverse()
.find((d) => d.context.getTitle)
const title = matchWithTitle?.context.getTitle() || 'My App'
return (
<html>
<head>
<title>{title}</title>
</head>
<body>{/* ... */}</body>
</html>
)
},
})
// src/routes/__root.tsx
export const Route = createRootRoute({
component: () => {
const matches = useRouterState({ select: (s) => s.matches })
const matchWithTitle = [...matches]
.reverse()
.find((d) => d.context.getTitle)
const title = matchWithTitle?.context.getTitle() || 'My App'
return (
<html>
<head>
<title>{title}</title>
</head>
<body>{/* ... */}</body>
</html>
)
},
})
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