Update card collapsed state handling to change child view model visibility attribute

panel/models/card.ts

@@ -22,13 +22,15 @@ export class CardView extends ColumnView {
 
   button_el: HTMLButtonElement
   header_el: HTMLElement
+  initially_collapsed: boolean
 
   readonly collapsed_style = new DOM.InlineStyleSheet()
 
   override connect_signals(): void {
     super.connect_signals()
 
     const {active_header_background, collapsed, header_background, header_color, hide_header} = this.model.properties
+    this.initially_collapsed = this.model.collapsed
     this.on_change(collapsed, () => this._collapse())
     this.on_change([header_color, hide_header], () => this.render())
 
@@ -106,11 +108,11 @@ export class CardView extends ColumnView {
       header.r_after_render()
     }
 
-    if (this.model.collapsed) {
-      return
-    }
-
     for (const child_view of this.child_views.slice(1)) {
+      if (this.initially_collapsed) {
+        child_view.model.visible = false
+        this.initially_collapsed = false
+      }
       this.shadow_el.appendChild(child_view.el)
       child_view.render()
       child_view.r_after_render()

panel/tests/test_server.py

@@ -798,6 +798,7 @@
     wait_until(lambda: len(counts) > 0 and max(counts) > 1)
 
 
+@pytest.mark.flaky(max_runs=3)
 def test_server_thread_pool_change_event(server_implementation, threads):
     button = Button(name='Click')
     button2 = Button(name='Click')
@@ -823,7 +824,7 @@
         button2._server_change(doc, model.ref['id'], None, 'clicks', 0, 1)
 
     # Checks whether Button on_click callback was executed concurrently
     wait_until(lambda: len(counts) > 0 and max(counts) > 1)
 
 
 def test_server_thread_pool_bokeh_event(server_implementation, threads):

panel/tests/ui/layout/test_accordion.py

@@ -19,9 +19,9 @@ def accordion_components():
     return d0, d1
 
 
-def is_collapsed(card_object, card_content):
+def is_collapsed(card_object, card_content, page):
     expect(card_object.locator('svg')).to_have_class("icon icon-tabler icons-tabler-outline icon-tabler-chevron-right")
-    expect(card_object).not_to_contain_text(card_content)
+    expect(page.get_by_text(card_content)).to_be_hidden()
     return True
 
 
@@ -51,8 +51,8 @@ def test_accordion_default(page, accordion_components):
     expect(d1_object).to_contain_text(d1.name)
 
     # cards are collapsed and their content is hidden by default
-    assert is_collapsed(card_object=d0_object, card_content=d0.text)
-    assert is_collapsed(card_object=d1_object, card_content=d1.text)
+    assert is_collapsed(card_object=d0_object, card_content=d0.text, page=page)
+    assert is_collapsed(card_object=d1_object, card_content=d1.text, page=page)
 
     # cards can be expanded simultaneously
     d0_object.click()
@@ -94,7 +94,7 @@ def test_accordion_active(page, accordion_components):
     # second card is collapsed and its content is hidden
     d1_object = accordion_elements.nth(1)
     d1_object.wait_for()
-    assert is_collapsed(card_object=d1_object, card_content=d1.text)
+    assert is_collapsed(card_object=d1_object, card_content=d1.text, page=page)
 
 
 def test_accordion_objects(page, accordion_components):
@@ -127,11 +127,11 @@ def test_accordion_toggle(page, accordion_components):
     # click to expand the first card, 2nd card is collapsed
     d0_object.click()
     assert is_expanded(card_object=d0_object, card_content=d0.text)
-    assert is_collapsed(card_object=d1_object, card_content=d1.text)
+    assert is_collapsed(card_object=d1_object, card_content=d1.text, page=page)
 
     # click to expand the 2nd card, 1st card is collapsed
     d1_object.click()
-    assert is_collapsed(card_object=d0_object, card_content=d0.text)
+    assert is_collapsed(card_object=d0_object, card_content=d0.text, page=page)
     assert is_expanded(card_object=d1_object, card_content=d1.text)
 
 
@@ -150,15 +150,15 @@ def test_accordion_append(page, accordion_components):
     expect(accordion_elements).to_have_count(1)
     # collapsed by default
     d0_object = accordion_elements.nth(0)
-    assert is_collapsed(card_object=d0_object, card_content=d0.text)
+    assert is_collapsed(card_object=d0_object, card_content=d0.text, page=page)
 
     # add new element d1
     accordion.append(d1)
     expect(accordion_elements).to_have_count(2)
     d1_object = accordion_elements.nth(1)
     # both cards are collapsed
-    assert is_collapsed(card_object=d0_object, card_content=d0.text)
-    assert is_collapsed(card_object=d1_object, card_content=d1.text)
+    assert is_collapsed(card_object=d0_object, card_content=d0.text, page=page)
+    assert is_collapsed(card_object=d1_object, card_content=d1.text, page=page)
 
 
 def test_accordion_extend(page, accordion_components):
@@ -179,9 +179,9 @@ def test_accordion_extend(page, accordion_components):
     d0_object = accordion_elements.nth(0)
     d1_object = accordion_elements.nth(1)
     d2_object = accordion_elements.nth(2)
-    assert is_collapsed(card_object=d0_object, card_content=d0.text)
-    assert is_collapsed(card_object=d1_object, card_content=d1.text)
-    assert is_collapsed(card_object=d2_object, card_content=d2.text)
+    assert is_collapsed(card_object=d0_object, card_content=d0.text, page=page)
+    assert is_collapsed(card_object=d1_object, card_content=d1.text, page=page)
+    assert is_collapsed(card_object=d2_object, card_content=d2.text, page=page)
 
 
 def test_accordion_clear(page, accordion_components):