feat(client): add onContentUpdated composition API (#1620)

Co-authored-by: Mister-Hope <[email protected]>
Co-authored-by: Xinyu Liu <[email protected]>

e2e/docs/.vuepress/theme/client/components/MarkdownContentHooks.vue

@@ -0,0 +1,45 @@
+<script lang="ts" setup>
+import { ref, watch } from 'vue'
+import { onContentUpdated, useRoutePath } from 'vuepress/client'
+
+const mounted = ref('')
+const beforeUnmount = ref('')
+
+const mountedCount = ref(0)
+const updatedCount = ref(0)
+
+const routePath = useRoutePath()
+
+watch(routePath, () => {
+  updatedCount.value = 0
+})
+
+onContentUpdated((reason) => {
+  switch (reason) {
+    case 'mounted':
+      mounted.value = routePath.value
+      mountedCount.value++
+      break
+    case 'updated':
+      updatedCount.value++
+      break
+    case 'beforeUnmount':
+      beforeUnmount.value = routePath.value
+      break
+    default:
+  }
+})
+</script>
+
+<template>
+  <div class="markdown-content-hooks">
+    <h3>markdown content hooks</h3>
+    <p class="markdown-content-mounted">
+      mounted: {{ mounted }} {{ mountedCount }}
+    </p>
+    <p class="markdown-content-beforeUnmount">
+      beforeUnmount: {{ beforeUnmount }}
+    </p>
+    <p class="markdown-content-updated">updatedCount: {{ updatedCount }}</p>
+  </div>
+</template>

e2e/docs/.vuepress/theme/client/layouts/Layout.vue

@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import { Content, useSiteData } from 'vuepress/client'
+import MarkdownContentHooks from '../components/MarkdownContentHooks.vue'
 
 const siteData = useSiteData()
 </script>
@@ -18,6 +19,8 @@ const siteData = useSiteData()
     <main class="e2e-theme-content">
       <Content />
     </main>
+
+    <MarkdownContentHooks />
   </div>
 </template>
 

e2e/docs/composables/on-content-updated.md

@@ -0,0 +1,3 @@
+## title
+
+content

e2e/tests/composables/on-content-updated.spec.ts

@@ -0,0 +1,69 @@
+import { expect, test } from '@playwright/test'
+import { BUNDLER, IS_DEV } from '../../utils/env'
+import { readSourceMarkdown, writeSourceMarkdown } from '../../utils/source'
+
+const updateMarkdownContent = async (): Promise<void> => {
+  const content = await readSourceMarkdown('composables/on-content-updated.md')
+  await writeSourceMarkdown(
+    'composables/on-content-updated.md',
+    `${content}\n\nUpdated content`,
+  )
+}
+
+const restoreMarkdownContent = async (): Promise<void> => {
+  await writeSourceMarkdown(
+    'composables/on-content-updated.md',
+    '## title\n\ncontent\n',
+  )
+}
+
+test.afterAll(async () => {
+  await restoreMarkdownContent()
+})
+
+test('should call content hook on mounted', async ({ page }) => {
+  await page.goto('composables/on-content-updated.html')
+  const mountedLocator = page.locator(
+    '.markdown-content-hooks .markdown-content-mounted',
+  )
+  await expect(mountedLocator).toHaveText(
+    'mounted: /composables/on-content-updated.html 1',
+  )
+
+  // update content but mounted hook should not be called twice
+  await updateMarkdownContent()
+  await expect(mountedLocator).toHaveText(
+    'mounted: /composables/on-content-updated.html 1',
+  )
+})
+
+test('should call content hook on beforeUnmount', async ({ page }) => {
+  await page.goto('composables/on-content-updated.html')
+
+  const beforeUnmountLocator = page.locator(
+    '.markdown-content-hooks .markdown-content-beforeUnmount',
+  )
+
+  await page.locator('.e2e-theme-nav ul > li > a').nth(0).click()
+
+  await expect(beforeUnmountLocator).toHaveText('beforeUnmount: /')
+})
+
+/**
+ * Updated hooks are only supported for use in development environments.
+ * In CI environments, under both Linux and Windows, using Vite fails to correctly trigger hooks.
+ */
+if (IS_DEV && BUNDLER !== 'vite') {
+  test('should call content hook on updated', async ({ page }) => {
+    await page.goto('composables/on-content-updated.html')
+    const updatedLocator = page.locator(
+      '.markdown-content-hooks .markdown-content-updated',
+    )
+
+    await updateMarkdownContent()
+    await expect(updatedLocator).toHaveText(`updatedCount: 1`)
+
+    await updateMarkdownContent()
+    await expect(updatedLocator).toHaveText(`updatedCount: 2`)
+  })
+}

packages/client/src/components/Content.ts

@@ -1,6 +1,17 @@
-import { computed, defineAsyncComponent, defineComponent, h } from 'vue'
-import { usePageComponent } from '../composables/index.js'
+import { computed, defineAsyncComponent, defineComponent, h, watch } from 'vue'
+import { usePageComponent, usePageFrontmatter } from '../composables/index.js'
+import { contentUpdatedCallbacks } from '../internal/contentUpdatedCallbacks'
 import { resolveRoute } from '../router/index.js'
+import type { ContentUpdatedReason } from '../types/index.js'
+
+/**
+ * Execute all callbacks registered via `onContentUpdated`.
+ *
+ * @internal
+ */
+const runContentUpdatedCallbacks = (reason: ContentUpdatedReason): void => {
+  contentUpdatedCallbacks.value.forEach((fn) => fn(reason))
+}
 
 /**
  * Markdown rendered content
@@ -26,6 +37,26 @@ export const Content = defineComponent({
       )
     })
 
-    return () => h(ContentComponent.value)
+    const frontmatter = usePageFrontmatter()
+    watch(
+      frontmatter,
+      () => {
+        runContentUpdatedCallbacks('updated')
+      },
+      { deep: true, flush: 'post' },
+    )
+
+    return () =>
+      h(ContentComponent.value, {
+        onVnodeMounted: () => {
+          runContentUpdatedCallbacks('mounted')
+        },
+        onVnodeUpdated: () => {
+          runContentUpdatedCallbacks('updated')
+        },
+        onVnodeBeforeUnmount: () => {
+          runContentUpdatedCallbacks('beforeUnmount')
+        },
+      })
   },
 })

packages/client/src/composables/index.ts

@@ -1,3 +1,4 @@
 export * from './clientData.js'
 export * from './clientDataUtils.js'
+export * from './onContentUpdated.js'
 export * from './updateHead.js'

packages/client/src/composables/onContentUpdated.ts

@@ -0,0 +1,16 @@
+import { onUnmounted } from 'vue'
+import { contentUpdatedCallbacks } from '../internal/contentUpdatedCallbacks'
+import type { ContentUpdatedCallback } from '../types/index.js'
+
+/**
+ * Register callback that is called every time the markdown content is updated
+ * in the DOM.
+ */
+export const onContentUpdated = (fn: ContentUpdatedCallback): void => {
+  contentUpdatedCallbacks.value.push(fn)
+  onUnmounted(() => {
+    contentUpdatedCallbacks.value = contentUpdatedCallbacks.value.filter(
+      (f) => f !== fn,
+    )
+  })
+}

packages/client/src/internal/contentUpdatedCallbacks.ts

@@ -0,0 +1,9 @@
+import type { Ref } from 'vue'
+import { shallowRef } from 'vue'
+import type { ContentUpdatedCallback } from '../types/index.js'
+
+/**
+ * Global content updated callbacks ref
+ */
+export const contentUpdatedCallbacks: Ref<ContentUpdatedCallback[]> =
+  shallowRef([])

packages/client/src/types/index.ts

@@ -1,4 +1,5 @@
 export type * from './clientConfig.js'
 export type * from './clientData.js'
+export type * from './onContentUpdated.js'
 export type * from './createVueAppFunction.js'
 export type * from './routes.js'

packages/client/src/types/onContentUpdated.ts

@@ -0,0 +1,3 @@
+export type ContentUpdatedReason = 'beforeUnmount' | 'mounted' | 'updated'
+
+export type ContentUpdatedCallback = (reason: ContentUpdatedReason) => unknown