Revert "fix: also set ssrAppId for first Vue app when ssrAttribute ex…

…ists"

This reverts commit 4cb5724.

examples/ssr/App.js

@@ -66,7 +66,8 @@ export default function createApp () {
     ]
   })
 
-  const App = ({
+  const app = new Vue({
+    router,
     metaInfo () {
       return {
         title: 'Boring Title',
@@ -156,11 +157,6 @@ export default function createApp () {
     </div>`
   })
 
-  const app = new Vue({
-    router,
-    render: h => h(App)
-  })
-
   const { set } = app.$meta().addApp('custom')
   set({
     bodyAttrs: { class: 'custom-app' },

src/shared/mixin.js

@@ -1,7 +1,6 @@
 import { triggerUpdate } from '../client/update'
 import { isUndefined, isFunction } from '../utils/is-type'
 import { find } from '../utils/array'
-import { getTag } from '../utils/elements'
 import { rootConfigKey } from './constants'
 import { hasMetaInfo } from './meta-helpers'
 import { addNavGuards } from './nav-guards'
@@ -22,6 +21,12 @@ export default function createMixin (Vue, options) {
       const $options = this.$options
       const devtoolsEnabled = Vue.config.devtools
 
+      if (this === $root) {
+        this.$on('hook:beforeMount', function () {
+          wasServerRendered = this.$el && this.$el.nodeType === 1 && this.$el.hasAttribute('data-server-rendered')
+        })
+      }
+
       Object.defineProperty(this, '_hasMetaInfo', {
         configurable: true,
         get () {
@@ -34,22 +39,6 @@ export default function createMixin (Vue, options) {
         }
       })
 
-      if (this === $root) {
-        $root.$once('hook:beforeMount', function () {
-          wasServerRendered = this.$el && this.$el.nodeType === 1 && this.$el.hasAttribute('data-server-rendered')
-
-          // In most cases when you have a SSR app it will be the first app thats gonna be
-          // initiated, if we cant detect the data-server-rendered attribute from Vue but we
-          // do see our own ssrAttribute then _assume_ the Vue app with appId 1 is the ssr app
-          // attempted fix for #404 & #562, but we rly need to refactor how we pass appIds from
-          // ssr to the client
-          if (!wasServerRendered && $root[rootConfigKey] && $root[rootConfigKey].appId === 1) {
-            const htmlTag = getTag({}, 'html')
-            wasServerRendered = htmlTag && htmlTag.hasAttribute(options.ssrAttribute)
-          }
-        })
-      }
-
       // Add a marker to know if it uses metaInfo
       // _vnode is used to know that it's attached to a real component
       // useful if we use some mixin to add some meta tags (like nuxt-i18n)
@@ -118,7 +107,6 @@ export default function createMixin (Vue, options) {
 
             this.$on('hook:beforeMount', function () {
               const $root = this[rootKey]
-
               // if this Vue-app was server rendered, set the appId to 'ssr'
               // only one SSR app per page is supported
               if (wasServerRendered) {
@@ -131,37 +119,35 @@ export default function createMixin (Vue, options) {
           this.$on('hook:mounted', function () {
             const $root = this[rootKey]
 
-            if ($root[rootConfigKey].initialized) {
-              return
+            if (!$root[rootConfigKey].initialized) {
+              // used in triggerUpdate to check if a change was triggered
+              // during initialization
+              $root[rootConfigKey].initializing = true
+
+              // refresh meta in nextTick so all child components have loaded
+              this.$nextTick(function () {
+                const { tags, metaInfo } = $root.$meta().refresh()
+
+                // After ssr hydration (identifier by tags === false) check
+                // if initialized was set to null in triggerUpdate. That'd mean
+                // that during initilazation changes where triggered which need
+                // to be applied OR a metaInfo watcher was triggered before the
+                // current hook was called
+                // (during initialization all changes are blocked)
+                if (tags === false && $root[rootConfigKey].initialized === null) {
+                  this.$nextTick(() => triggerUpdate(options, $root, 'init'))
+                }
+
+                $root[rootConfigKey].initialized = true
+                delete $root[rootConfigKey].initializing
+
+                // add the navigation guards if they havent been added yet
+                // they are needed for the afterNavigation callback
+                if (!options.refreshOnceOnNavigation && metaInfo.afterNavigation) {
+                  addNavGuards($root)
+                }
+              })
             }
-
-            // used in triggerUpdate to check if a change was triggered
-            // during initialization
-            $root[rootConfigKey].initializing = true
-
-            // refresh meta in nextTick so all child components have loaded
-            this.$nextTick(function () {
-              const { tags, metaInfo } = $root.$meta().refresh()
-
-              // After ssr hydration (identifier by tags === false) check
-              // if initialized was set to null in triggerUpdate. That'd mean
-              // that during initilazation changes where triggered which need
-              // to be applied OR a metaInfo watcher was triggered before the
-              // current hook was called
-              // (during initialization all changes are blocked)
-              if (tags === false && $root[rootConfigKey].initialized === null) {
-                this.$nextTick(() => triggerUpdate(options, $root, 'init'))
-              }
-
-              $root[rootConfigKey].initialized = true
-              delete $root[rootConfigKey].initializing
-
-              // add the navigation guards if they havent been added yet
-              // they are needed for the afterNavigation callback
-              if (!options.refreshOnceOnNavigation && metaInfo.afterNavigation) {
-                addNavGuards($root)
-              }
-            })
           })
           // add the navigation guards if requested
           if (options.refreshOnceOnNavigation) {