Use server-rendered template for preview avatar and author header.

Replace data-attribute approach with a <template> element inside the
reply form. The server renders the avatar img and author name once;
JS clones the HTML for each preview update. This fixes the missing
avatar in the live preview and handles anonymous name updates.

remarkbox/static/js/custom.js

@@ -60,34 +60,26 @@ function isReplyForm(form) {
 
 function wrapPreviewAsNode(html, form) {
     // Wrap preview HTML in node-like markup so it looks like a live comment.
-    var name = '';
-    var avatarHtml = '';
+    // Uses server-rendered <template> for the avatar + author header.
+    var template = form.querySelector('.preview-header-template');
+    if (!template || !template.innerHTML.trim()) return html;
 
-    if (form.hasAttribute('data-author-name')) {
-        // Authenticated user.
-        name = form.getAttribute('data-author-name');
-        var avatarSrc = form.getAttribute('data-author-avatar');
-        if (avatarSrc) {
-            avatarHtml = '<img src="' + avatarSrc + '" class="avatar nested-avatar" align="left" />';
-        }
-    } else {
-        // Anonymous user — read name from input.
-        var nameInput = form.querySelector('[name="anonymous_name"]');
-        if (nameInput && nameInput.value.trim()) {
-            name = nameInput.value.trim();
-        } else {
-            name = 'Anonymous';
+    var headerHtml = template.innerHTML;
+
+    // For anonymous users, update name from the input field.
+    var nameInput = form.querySelector('[name="anonymous_name"]');
+    if (nameInput) {
+        var name = nameInput.value.trim() || 'Anonymous';
+        var anonEl = template.content.querySelector('.preview-anon-name');
+        if (anonEl) {
+            headerHtml = headerHtml.replace(
+                '>' + anonEl.textContent + '<',
+                '>' + escapeHtml(name) + '<'
+            );
         }
     }
 
-    if (!name) return html;
-
-    return avatarHtml
-        + '<span class="author-and-date">'
-        + '<strong>' + escapeHtml(name) + '</strong> '
-        + '<span class="date">just now</span>'
-        + '</span>'
-        + '<div class="node-data">' + html + '</div>';
+    return headerHtml + '<div class="node-data">' + html + '</div>';
 }
 
 // CSS-based toggle for smoother animations.

remarkbox/templates/snippets/forms.j2

@@ -5,12 +5,7 @@
 <p>This thread was locked to prevent additional comments.</p>
 {% else %}
 
-<form method="post" action="{{ request.link_prefix }}/{{ node.id }}/reply"
-      {% if request.user and request.user.authenticated %}
-      data-author-name="{{ request.user.name }}"
-      data-author-avatar="{{ request.user.avatar_uri(size=request.avatar_size) }}"
-      {% endif %}
-      onsubmit="submit.disabled = true; return true;">
+<form method="post" action="{{ request.link_prefix }}/{{ node.id }}/reply" onsubmit="submit.disabled = true; return true;">
 
 {# the first if statement gaurds the 2nd and is an optimization #}
 {% if node.id == request.node.id %}
@@ -31,6 +26,21 @@
   {% set submit_button_value = request.namespace.submit_button_text or 'save message' %}
   {% include 'submit.j2' %}
 
+  <template class="preview-header-template">
+  {% if request.user and request.user.authenticated %}
+  <img src="{{ request.user.avatar_uri(size=request.avatar_size) }}" class="avatar nested-avatar" align="left" />
+  <span class="author-and-date">
+    <strong>{{ request.user.name }}</strong>
+    <span class="date">just now</span>
+  </span>
+  {% elif request.namespace.allow_anonymous %}
+  <span class="author-and-date">
+    <strong class="preview-anon-name">Anonymous</strong>
+    <span class="date">just now</span>
+  </span>
+  {% endif %}
+  </template>
+
   <details class="preview-details js-only" open>
   <summary class="action link preview-toggle"><span class="when-open">hide preview ▲</span><span class="when-closed">show preview ▼</span></summary>
   <div id='preview-{{ node.id }}' name='preview' class='preview js-only'></div>