feat($core): global variable "__VUEPRESS__" to store runtime key infos

Author: ulivz

packages/@vuepress/core/lib/client/clientEntry.js

@@ -4,7 +4,7 @@ import { createApp } from './app'
 
 const { app, router } = createApp(false /* isServer */)
 
-window.__VUEPRESS_VERSION__ = {
+window.__VUEPRESS__ = {
   version: VUEPRESS_VERSION,
   hash: LAST_COMMIT_HASH
 }

packages/@vuepress/core/lib/client/components/Content.js

@@ -1,3 +1,4 @@
+import { setGlobalInfo } from '@app/util'
 
 export default {
   props: {
@@ -9,6 +10,8 @@ export default {
   },
   render (h) {
     const pageKey = this.pageKey || this.$parent.$page.key
+    setGlobalInfo('pageKey', pageKey)
+
     if (pageKey) {
       return h(pageKey)
     }

packages/@vuepress/core/lib/client/components/GlobalLayout.vue

@@ -3,9 +3,11 @@
 </template>
 
 <script>
+import { setGlobalInfo } from '@app/util'
+
 export default {
-  computed: {
-    layout () {
+  methods: {
+    getLayout () {
       if (this.$page.path) {
         const layout = this.$page.frontmatter.layout
         if (layout && (this.$vuepress.getLayoutAsyncComponent(layout)
@@ -16,6 +18,14 @@ export default {
       }
       return 'NotFound'
     }
+  },
+
+  computed: {
+    layout () {
+      const layout = this.getLayout()
+      setGlobalInfo('layout', layout)
+      return layout
+    }
   }
 }
 </script>

packages/@vuepress/core/lib/client/util.js

@@ -182,3 +182,16 @@ export function normalizeConfig (component, rawConfig) {
   }
   return rawConfig
 }
+
+/**
+ * Set global info in `window.__VUEPRESS__` for debugging.
+ *
+ * @param {string}key
+ * @param {any} value
+ */
+export function setGlobalInfo (key, value) {
+  if (!window.__VUEPRESS__ || typeof window === 'undefined') {
+    return
+  }
+  window.__VUEPRESS__[key] = value
+}