faster HiddenFromSSR implementation

package-lock.json

@@ -8131,20 +8131,15 @@
           }
         },
         "ajv": {
-          "version": "6.2.1",
+          "version": "6.3.0",
-          "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.2.1.tgz",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.3.0.tgz",
-          "integrity": "sha1-KKarxJOiq+D7TIUHrK7bQ/pVBnE=",
+          "integrity": "sha1-FlCkERTvAFdMrBC4Ay2PTBSBLac=",
           "requires": {
             "fast-deep-equal": "1.0.0",
             "fast-json-stable-stringify": "2.0.0",
             "json-schema-traverse": "0.3.1"
           }
         },
-        "ajv-keywords": {
-          "version": "3.1.0",
-          "resolved": "https://registry.npmjs.org/ajv-keywords/-/ajv-keywords-3.1.0.tgz",
-          "integrity": "sha1-rCsnk5xUPpXSwG5/f1wnvkqlQ74="
-        },
         "ansi-styles": {
           "version": "3.2.1",
           "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-3.2.1.tgz",
@@ -8341,7 +8336,7 @@
           "requires": {
             "acorn": "5.3.0",
             "acorn-dynamic-import": "2.0.2",
-            "ajv": "6.2.1",
+            "ajv": "6.3.0",
             "ajv-keywords": "3.1.0",
             "async": "2.6.0",
             "enhanced-resolve": "3.4.1",

routes/_components/HiddenFromSSR.html

@@ -1,13 +1,22 @@
-<div class="{{hidden ? 'hidden' : ''}}">
+<!-- toggled in 2xx.html based on whether the user is logged in or not -->
+<div class="hidden-from-ssr {{shown ? 'shown' : ''}}">
   <slot></slot>
 </div>
+<style>
+  .hidden-from-ssr {
+    opacity: 0;
+  }
+  .hidden-from-ssr.shown {
+    opacity: 1;
+  }
+</style>
 <script>
   export default {
-    data: () => ({
-      hidden: true
-    }),
     oncreate () {
-      this.set({hidden: !process.browser})
+      this.set({ shown: true })
-    }
+    },
+    data: () => ({
+      shown: false
+    })
   }
 </script>

templates/2xx.html

@@ -21,8 +21,8 @@ body.offline,body.theme-hotpants.offline,body.theme-majesty.offline,body.theme-o
 
   <noscript>
     <style>
-			.hidden {
+      .hidden-from-ssr {
-				opacity: 1;
+        opacity: 1 !important;
       }
     </style>
   </noscript>
@@ -63,6 +63,12 @@ body.offline,body.theme-hotpants.offline,body.theme-majesty.offline,body.theme-o
         }
       }
     }
+    if (!localStorage.store_currentInstance) {
+      // if not logged in, show all these "hidden-from-ssr" elements
+      let style = document.createElement('style')
+      style.textContent = '.hidden-from-ssr { opacity: 1 !important; }'
+      document.head.appendChild(style)
+    }
   </script>
   <svg xmlns="http://www.w3.org/2000/svg" style="display:none;">
     <!-- auto-generated w/ build-svg.js -->