From 2e9ecad18b084a7e20011d395df4e99316a6e7d3 Mon Sep 17 00:00:00 2001
From: Brandon Marshall <bmarshal@adobe.com>
Date: Thu, 29 Jan 2026 12:51:47 -0800
Subject: [PATCH 1/2] fix: prevent plugin iframe blank on Library re-render

---
 blocks/edit/da-library/da-library.js          | 52 ++++++++++--------
 .../blocks/edit/da-library/da-library.test.js | 55 +++++++++++++++++++
 2 files changed, 84 insertions(+), 23 deletions(-)
 create mode 100644 test/unit/blocks/edit/da-library/da-library.test.js

diff --git a/blocks/edit/da-library/da-library.js b/blocks/edit/da-library/da-library.js
index 730b25f6b..e67fe1c00 100644
--- a/blocks/edit/da-library/da-library.js
+++ b/blocks/edit/da-library/da-library.js
@@ -8,6 +8,7 @@ import {
   createRef,
   ref,
   nothing,
+  repeat,
 } from 'da-lit';
 import { getNx, sanitizePathParts } from '../../../scripts/utils.js';
 import { getBlocks, getBlockVariants } from './helpers/index.js';
@@ -62,6 +63,7 @@ class DaLibrary extends LitElement {
     _blockPreviewPath: { state: true },
     _previewItemName: { Type: String },
     _previewStatus: { Type: Object },
+    _activePane: { state: true },
   };
 
   constructor() {
@@ -182,13 +184,12 @@ class DaLibrary extends LitElement {
     const toShow = this.shadowRoot.querySelector(`[data-library-type="${type}"]`);
     toShow.classList.remove('forward');
     toShow.inert = false;
-    const pluginIframe = toShow.querySelector('iframe');
-    if (!pluginIframe) return;
-    pluginIframe.src = pluginIframe.dataset.src;
+    this._activePane = type;
   }
 
   handleBack(e) {
     const { target } = e;
+    this._activePane = null;
     target.closest('.palette-pane').classList.add('forward');
     target.closest('.palette-pane').inert = true;
     const wrapper = target.closest('.palette-wrapper');
@@ -199,6 +200,7 @@ class DaLibrary extends LitElement {
 
   handleCloseSearch() {
     this._searchStr = '';
+    this._activePane = null;
     this.searchInputRef.value.value = '';
   }
 
@@ -383,7 +385,6 @@ class DaLibrary extends LitElement {
         @close=${this.handlePreviewClose}>
         ${status === 200 ? html`<iframe
           class="da-dialog-block-preview-frame"
-          data-src="${this._blockPreviewPath}"
           src="${this._blockPreviewPath}"
           @load=${this.handlePreviewLoad}
           allow="clipboard-write *"></iframe>` : html`<div style="margin: 0 24px">${error || 'This block / template has not been previewed.'}</div>`}
@@ -531,8 +532,7 @@ class DaLibrary extends LitElement {
     return html`
       <div class="da-library-type-plugin">
         <iframe
-          data-src="${preload ? null : url}"
-          src="${preload ? url : null}"
+          src="${preload ? url : nothing}"
           @load=${this.handlePluginLoad}
           allow="clipboard-write *"></iframe>
       </div>`;
@@ -563,11 +563,7 @@ class DaLibrary extends LitElement {
     this._previewStatus = { ...this._previewStatus, ...status };
   }
 
-  async renderLibrary({ name, sources, url, format, class: className }) {
-    const isPlugin = className.split(' ').some((val) => val === 'is-plugin');
-
-    if (isPlugin) return this.renderPlugin({ sources, url });
-
+  async renderLibrary({ name, sources, format }) {
     if (name === 'blocks') {
       if (!data.blocks) {
         data.blocks = await getBlocks(sources);
@@ -616,12 +612,14 @@ class DaLibrary extends LitElement {
   renderMainMenu() {
     return html`
       <ul class="da-library-item-list da-library-item-list-main">
-        ${this._libraryList.map(
+        ${repeat(
+          this._libraryList,
+          (library) => library.name,
           (library) => html`
           <li>
             <button
               data-library-name="${library.name}"
-              class="${library.class || library.name} ${library.url ? 'is-plugin' : ''}"
+              class="${library.class || library.name}"
               style="${library.icon ? `background-image: url(${library.icon})` : ''}"
               @click=${(e) => this.handleLibSwitch(e, library)}>
               <span class="library-type-name">${library.title || library.name}</span>
@@ -653,16 +651,24 @@ class DaLibrary extends LitElement {
           </div>
           ${this._searchStr ? this.renderSearch() : this.renderMainMenu()}
         </div>
-        ${this._libraryList.map(
-          (library) => html`
-          <div class="palette-pane forward" data-library-type="${library.name}" inert>
-            <div class="palette-pane-header">
-              <button class="palette-back" @click=${this.handleBack}>Back</button>
-              <h2>${library.name}</h2>
-            </div>
-            ${until(this.renderLibrary(library), html`<span>Loading...</span>`)}
-          </div>
-        `,
+        ${repeat(
+          this._libraryList,
+          (library) => library.name,
+          (library) => {
+            const isPlugin = library.class?.includes('is-plugin');
+
+            return html`
+              <div class="palette-pane forward" data-library-type="${library.name}" inert>
+                <div class="palette-pane-header">
+                  <button class="palette-back" @click=${this.handleBack}>Back</button>
+                  <h2>${library.name}</h2>
+                </div>
+                ${isPlugin
+                  ? this.renderPlugin(library, this._activePane === library.name)
+                  : until(this.renderLibrary(library), html`<span>Loading...</span>`)}
+              </div>
+            `;
+          },
         )}
       </div>
       <div class="da-library-preview">
diff --git a/test/unit/blocks/edit/da-library/da-library.test.js b/test/unit/blocks/edit/da-library/da-library.test.js
new file mode 100644
index 000000000..7b76e4ee7
--- /dev/null
+++ b/test/unit/blocks/edit/da-library/da-library.test.js
@@ -0,0 +1,55 @@
+/* eslint-disable no-underscore-dangle */
+import { expect } from '@esm-bundle/chai';
+import { setNx } from '../../../../../scripts/utils.js';
+
+const MOCK_PLUGINS = [
+  { name: 'plugin1', class: 'plugin1 is-plugin', url: 'http://localhost:3000/test/plugins/plugin1' },
+  { name: 'plugin2', class: 'plugin2 is-plugin', url: 'http://localhost:3000/test/plugins/plugin2' },
+];
+
+let daLibrary;
+
+describe('Da Library', () => {
+  before(async () => {
+    setNx('/test/fixtures/nx', { hostname: 'localhost' });
+    await import('../../../../../blocks/edit/da-library/da-library.js');
+  });
+
+  beforeEach(async () => {
+    document.body.innerHTML = '<da-library></da-library>';
+    daLibrary = document.querySelector('da-library');
+    daLibrary._libraryList = MOCK_PLUGINS;
+    daLibrary._activePane = undefined;
+    await daLibrary.updateComplete;
+  });
+
+  afterEach(() => {
+    document.body.innerHTML = '';
+  });
+
+  it('tracks active pane changes', async () => {
+    expect(daLibrary._activePane).to.be.undefined;
+
+    const testPluginButton = daLibrary.shadowRoot.querySelector('.plugin1');
+    testPluginButton.click();
+    await daLibrary.updateComplete;
+    expect(daLibrary._activePane).to.equal('plugin1');
+
+    const plugin2Button = daLibrary.shadowRoot.querySelector('.plugin2');
+    plugin2Button.click();
+    await daLibrary.updateComplete;
+    expect(daLibrary._activePane).to.equal('plugin2');
+  });
+
+  it('update plugin url when active pane changes', async () => {
+    const testPluginButton = daLibrary.shadowRoot.querySelector('.plugin1');
+    const testPlugin = daLibrary.shadowRoot.querySelector('[data-library-type="plugin1"] iframe');
+    expect(daLibrary._activePane).to.be.undefined;
+    expect(testPlugin.src).to.equal('');
+
+    testPluginButton.click();
+    await daLibrary.updateComplete;
+    expect(daLibrary._activePane).to.equal('plugin1');
+    expect(testPlugin.src).to.equal('http://localhost:3000/test/plugins/plugin1');
+  });
+});

From 6e4c9a44b79a1500afb3278fa33b7bf6de660b5c Mon Sep 17 00:00:00 2001
From: Brandon Marshall <bmarshal@adobe.com>
Date: Fri, 6 Feb 2026 07:59:26 -0800
Subject: [PATCH 2/2] Update active pane

---
 blocks/edit/da-library/da-library.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/blocks/edit/da-library/da-library.js b/blocks/edit/da-library/da-library.js
index b4010b80b..b41e1171e 100644
--- a/blocks/edit/da-library/da-library.js
+++ b/blocks/edit/da-library/da-library.js
@@ -116,6 +116,8 @@ class DaLibrary extends LitElement {
       return;
     }
 
+    this._activePane = library.name;
+
     if (library.experience === 'dialog') {
       let dialog = this.shadowRoot.querySelector('.da-dialog-plugin');
       if (dialog) dialog.remove();
@@ -178,13 +180,11 @@ class DaLibrary extends LitElement {
     }
 
     const { target } = e;
-    const type = target.dataset.libraryName;
     target.closest('.palette-pane').classList.add('backward');
     target.closest('.palette-pane').inert = true;
-    const toShow = this.shadowRoot.querySelector(`[data-library-type="${type}"]`);
+    const toShow = this.shadowRoot.querySelector(`[data-library-type="${library.name}"]`);
     toShow.classList.remove('forward');
     toShow.inert = false;
-    this._activePane = type;
   }
 
   handleBack(e) {