导航阻止

导航阻止是一种防止导航发生的方式。通常在以下用户尝试导航的情况下使用：

存在未保存的更改
正在填写表单过程中
正在进行支付操作

在这些场景中，应向用户显示提示或自定义界面以确认是否要离开当前页面。

如果用户确认，导航将正常继续
如果用户取消，所有待处理的导航将被阻止

导航阻止的工作原理

导航阻止为底层历史API添加了一层或多层"拦截器"。当存在任何拦截器时，导航将通过以下方式之一暂停：

自定义UI
- 如果导航由路由层级可控的触发源引起，允许执行任何任务或向用户展示任何确认操作的UI。每个拦截器的blocker函数将按顺序异步执行。若任一拦截器函数返回或解析为true，则允许导航，其他拦截器继续执行直到全部通过。若任一拦截器返回或解析为false，则取消导航并忽略剩余blocker函数。
onbeforeunload事件
- 对于无法直接控制的页面事件，依赖浏览器的onbeforeunload事件。当用户尝试关闭标签页/窗口、刷新或以任何方式卸载页面资源时，浏览器将显示通用提示"确定要离开吗？"。用户确认则绕过所有拦截器卸载页面，取消则保持当前页面状态。

如何使用导航阻止

有两种使用方式：

基于钩子/逻辑的阻止
基于组件的阻止

基于钩子/逻辑的阻止

例如阻止表单存在未保存更改时的导航：

tsx

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  useBlocker({
    shouldBlockFn: () => {
      if (!formIsDirty()) return false

      const shouldLeave = confirm('Are you sure you want to leave?')
      return !shouldLeave
    },
  })

  // ...
}

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  useBlocker({
    shouldBlockFn: () => {
      if (!formIsDirty()) return false

      const shouldLeave = confirm('Are you sure you want to leave?')
      return !shouldLeave
    },
  })

  // ...
}

shouldBlockFn提供对current和next位置的类型安全访问：

tsx

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  // 始终阻止从/foo跳转到/bar/123?hello=world
  const { proceed, reset, status } = useBlocker({
    shouldBlockFn: ({ current, next }) => {
      return (
        current.routeId === '/foo' &&
        next.fullPath === '/bar/$id' &&
        next.params.id === 123 &&
        next.search.hello === 'world'
      )
    },
    withResolver: true,
  })

  // ...
}

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  // 始终阻止从/foo跳转到/bar/123?hello=world
  const { proceed, reset, status } = useBlocker({
    shouldBlockFn: ({ current, next }) => {
      return (
        current.routeId === '/foo' &&
        next.fullPath === '/bar/$id' &&
        next.params.id === 123 &&
        next.search.hello === 'world'
      )
    },
    withResolver: true,
  })

  // ...
}

更多useBlocker钩子信息参见API参考。

基于组件的阻止

除钩子方式外，可使用Block组件实现相同效果：

tsx

import { Block } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  return (
    <Block
      shouldBlockFn={() => {
        if (!formIsDirty()) return false

        const shouldLeave = confirm('Are you sure you want to leave?')
        return !shouldLeave
      }}
    />
  )

  // OR

  return (
    <Block shouldBlockFn={() => !formIsDirty} withResolver>
      {({ status, proceed, reset }) => <>{/* ... */}</>}
    </Block>
  )
}

import { Block } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  return (
    <Block
      shouldBlockFn={() => {
        if (!formIsDirty()) return false

        const shouldLeave = confirm('Are you sure you want to leave?')
        return !shouldLeave
      }}
    />
  )

  // OR

  return (
    <Block shouldBlockFn={() => !formIsDirty} withResolver>
      {({ status, proceed, reset }) => <>{/* ... */}</>}
    </Block>
  )
}

如何展示自定义UI？

多数情况下，在钩子中使用window.confirm配合withResolver: false即可明确提示用户。但在需要更贴合应用设计的非侵入式UI时：

注意： 当withResolver为true时，shouldBlockFn的返回值不会直接决定阻止结果。

带解析器的钩子自定义UI

tsx

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  const { proceed, reset, status } = useBlocker({
    shouldBlockFn: () => formIsDirty(),
    withResolver: true,
  })

  // ...

  return (
    <>
      {/* ... */}
      {status === 'blocked' && (
        <div>
          <p>Are you sure you want to leave?</p>
          <button onClick={proceed}>Yes</button>
          <button onClick={reset}>No</button>
        </div>
      )}
    </>
}

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  const { proceed, reset, status } = useBlocker({
    shouldBlockFn: () => formIsDirty(),
    withResolver: true,
  })

  // ...

  return (
    <>
      {/* ... */}
      {status === 'blocked' && (
        <div>
          <p>Are you sure you want to leave?</p>
          <button onClick={proceed}>Yes</button>
          <button onClick={reset}>No</button>
        </div>
      )}
    </>
}

不带解析器的钩子自定义UI

tsx

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  useBlocker({
    shouldBlockFn: () => {
      if (!formIsDirty()) {
        return false
      }

      const shouldBlock = new Promise<boolean>((resolve) => {
        // Using a modal manager of your choice
        modals.open({
          title: 'Are you sure you want to leave?',
          children: (
            <SaveBlocker
              confirm={() => {
                modals.closeAll()
                resolve(false)
              }}
              reject={() => {
                modals.closeAll()
                resolve(true)
              }}
            />
          ),
          onClose: () => resolve(true),
        })
      })
      return shouldBlock
    },
  })

  // ...
}

import { useBlocker } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  useBlocker({
    shouldBlockFn: () => {
      if (!formIsDirty()) {
        return false
      }

      const shouldBlock = new Promise<boolean>((resolve) => {
        // Using a modal manager of your choice
        modals.open({
          title: 'Are you sure you want to leave?',
          children: (
            <SaveBlocker
              confirm={() => {
                modals.closeAll()
                resolve(false)
              }}
              reject={() => {
                modals.closeAll()
                resolve(true)
              }}
            />
          ),
          onClose: () => resolve(true),
        })
      })
      return shouldBlock
    },
  })

  // ...
}

基于组件的自定义UI

Block组件通过渲染属性提供相同状态和函数：

tsx

import { Block } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  return (
    <Block shouldBlockFn={() => formIsDirty()} withResolver>
      {({ status, proceed, reset }) => (
        <>
          {/* ... */}
          {status === 'blocked' && (
            <div>
              <p>Are you sure you want to leave?</p>
              <button onClick={proceed}>Yes</button>
              <button onClick={reset}>No</button>
            </div>
          )}
        </>
      )}
    </Block>
  )
}

import { Block } from '@tanstack/solid-router'

function MyComponent() {
  const [formIsDirty, setFormIsDirty] = createSignal(false)

  return (
    <Block shouldBlockFn={() => formIsDirty()} withResolver>
      {({ status, proceed, reset }) => (
        <>
          {/* ... */}
          {status === 'blocked' && (
            <div>
              <p>Are you sure you want to leave?</p>
              <button onClick={proceed}>Yes</button>
              <button onClick={reset}>No</button>
            </div>
          )}
        </>
      )}
    </Block>
  )
}