feat: update title & description during dev

lib/app/composables/head.js

@@ -1,11 +1,20 @@
 import { watchEffect } from 'vue'
-import { useSiteData } from './siteData'
+import { siteDataRef } from './siteData'
 
 /**
  * @param {import('./pageData').PageDataRef} pageData
  */
 export function useUpdateHead(pageData) {
-  const siteData = useSiteData()
+  const descriptionTag = createHeadElement(['meta', {
+    name: 'description',
+    content: siteDataRef.value.description
+  }])
+  document.head.appendChild(descriptionTag)
+
+  const updateTitleAndDescription = () => {
+    document.title = siteDataRef.value.title
+    descriptionTag.setAttribute('content', siteDataRef.value.description)
+  }
 
   /**
    * @type {HTMLElement[]}
@@ -24,14 +33,8 @@ export function useUpdateHead(pageData) {
     tags.forEach((el) => document.head.removeChild(el))
     tags.length = 0
     if (newTags && newTags.length) {
-      newTags.forEach(([tag, attrs, innerHTML]) => {
-        const el = document.createElement(tag)
-        for (const key in attrs) {
-          el.setAttribute(key, attrs[key])
-        }
-        if (innerHTML) {
-          el.innerHTML = innerHTML
-        }
+      newTags.forEach((headConfig) => {
+        const el = createHeadElement(headConfig)
         document.head.appendChild(el)
         tags.push(el)
       })
@@ -39,7 +42,8 @@ export function useUpdateHead(pageData) {
   }
 
   watchEffect(() => {
-    updateHeadTags(siteHeadTags, siteData.value.head)
+    updateTitleAndDescription()
+    updateHeadTags(siteHeadTags, siteDataRef.value.head)
   })
 
   watchEffect(() => {
@@ -49,3 +53,17 @@ export function useUpdateHead(pageData) {
     )
   })
 }
+
+/**
+ * @param {import('src').HeadConfig} item
+ */
+function createHeadElement([tag, attrs, innerHTML]) {
+  const el = document.createElement(tag)
+  for (const key in attrs) {
+    el.setAttribute(key, attrs[key])
+  }
+  if (innerHTML) {
+    el.innerHTML = innerHTML
+  }
+  return el
+}

lib/app/composables/siteData.js

@@ -11,7 +11,7 @@ const parse = (data) => readonly(JSON.parse(data))
 /**
  * @type {import('vue').Ref<import('src').SiteData>}
  */
-const siteDataRef = ref(parse(serialized))
+export const siteDataRef = ref(parse(serialized))
 
 export function useSiteData() {
   return siteDataRef

lib/app/index.js

@@ -1,14 +1,9 @@
-import {
-  createApp as createClientApp,
-  createSSRApp,
-  ref,
-  readonly
-} from 'vue'
+import { createApp as createClientApp, createSSRApp, ref, readonly } from 'vue'
 import { Content } from './components/Content'
 import { createRouter, RouterSymbol } from './router'
 import { useUpdateHead } from './composables/head'
-import { useSiteData } from './composables/siteData'
-import { usePageData, pageDataSymbol } from './composables/pageData'
+import { siteDataRef } from './composables/siteData'
+import { pageDataSymbol } from './composables/pageData'
 import Theme from '/@theme/index'
 import { hot } from '@hmr'
 
@@ -17,6 +12,8 @@ const inBrowser = typeof window !== 'undefined'
 const NotFound = Theme.NotFound || (() => '404 Not Found')
 
 export function createApp() {
+  // unlike site data which is static across all requests, page data is
+  // distinct per-request.
   const pageDataRef = ref()
 
   if (__DEV__ && inBrowser) {
@@ -74,18 +71,16 @@ export function createApp() {
 
   app.component('Content', Content)
 
-  app.mixin({
-    beforeCreate() {
-      const siteRef = useSiteData()
-      const pageRef = usePageData()
-      Object.defineProperties(this, {
-        $site: {
-          get: () => siteRef.value
-        },
-        $page: {
-          get: () => pageRef.value
-        }
-      })
+  Object.defineProperties(app.config.globalProperties, {
+    $site: {
+      get() {
+        return siteDataRef.value
+      }
+    },
+    $page: {
+      get() {
+        return pageDataRef.value
+      }
     }
   })
 
@@ -93,7 +88,7 @@ export function createApp() {
     Theme.enhanceApp({
       app,
       router,
-      siteData: useSiteData()
+      siteData: siteDataRef
     })
   }