4 files changed, 20 insertions, 32 deletions

diff --git a/ext/bg/js/api.js b/ext/bg/js/api.js
index 6ab130a7..5c1aebb6 100644
--- a/ext/bg/js/api.js
+++ b/ext/bg/js/api.js
@@ -100,27 +100,9 @@ async function apiNoteView(noteId) {
 
 async function apiTemplateRender(template, data, dynamic) {
     if (dynamic) {
-        return new Promise((resolve, reject) => {
-            const sequence = utilBackend().sequenceNew();
-            const handler = event => {
-                if (event.data.sequence === sequence) {
-                    if (event.data.command === 'error') {
-                        reject(event.data.result);
-                    } else {
-                        resolve(event.data.result);
-                    }
-
-                    window.removeEventListener('message', handler);
-                }
-            };
-
-            window.addEventListener('message', handler);
-
-            const sandbox = utilBackend().sandbox();
-            sandbox.postMessage({template, data, sequence, command: 'render'}, '*');
-        });
+        return handlebarsRenderDynamic(template, data);
     } else {
-        return handlebarsRender(template, data);
+        return handlebarsRenderStatic(template, data);
     }
 }
 
diff --git a/ext/bg/js/backend.js b/ext/bg/js/backend.js
index 5061557b..7d68ed84 100644
--- a/ext/bg/js/backend.js
+++ b/ext/bg/js/backend.js
@@ -22,7 +22,6 @@ class Backend {
         this.translator = new Translator();
         this.anki = new AnkiNull();
         this.options = null;
-        this.sequence = 0;
     }
 
     async prepare() {
@@ -37,14 +36,6 @@ class Backend {
         }
     }
 
-    sequenceNew() {
-        return this.sequence++;
-    }
-
-    sandbox() {
-        return document.getElementById('sandbox').contentWindow;
-    }
-
     onOptionsUpdated(options) {
         this.options = utilIsolate(options);
 
diff --git a/ext/bg/js/handlebars.js b/ext/bg/js/handlebars.js
index e0804986..66d5fa2b 100644
--- a/ext/bg/js/handlebars.js
+++ b/ext/bg/js/handlebars.js
@@ -75,7 +75,7 @@ function handlebarsMultiLine(options) {
     return options.fn(this).split('\n').join('<br>');
 }
 
-function handlebarsRender(template, data) {
+function handlebarsRegisterHelpers() {
     if (Handlebars.partials !== Handlebars.templates) {
         Handlebars.partials = Handlebars.templates;
         Handlebars.registerHelper('dumpObject', handlebarsDumpObject);
@@ -84,6 +84,21 @@ function handlebarsRender(template, data) {
         Handlebars.registerHelper('kanjiLinks', handlebarsKanjiLinks);
         Handlebars.registerHelper('multiLine', handlebarsMultiLine);
     }
+}
+
+function handlebarsRenderStatic(name, data) {
+    handlebarsRegisterHelpers();
+    return Handlebars.templates[name](data).trim();
+}
+
+function handlebarsRenderDynamic(template, data) {
+    handlebarsRegisterHelpers();
+
+    Handlebars.yomichan_cache = Handlebars.yomichan_cache || {};
+    let instance = Handlebars.yomichan_cache[template];
+    if (!instance) {
+        instance = Handlebars.yomichan_cache[template] = Handlebars.compile(template);
+    }
 
-    return Handlebars.templates[template](data).trim();
+    return instance(data).trim();
 }
diff --git a/ext/bg/js/settings.js b/ext/bg/js/settings.js
index d4e6ab17..55b469d0 100644
--- a/ext/bg/js/settings.js
+++ b/ext/bg/js/settings.js
@@ -218,7 +218,7 @@ async function dictionaryGroupsPopulate(options) {
 
     for (const dictRow of dictRowsSort(dictRows, options)) {
         const dictOptions = options.dictionaries[dictRow.title] || {enabled: false, priority: 0};
-        const dictHtml = handlebarsRender('dictionary.html', {
+        const dictHtml = await apiTemplateRender('dictionary.html', {
             title: dictRow.title,
             version: dictRow.version,
             revision: dictRow.revision,