From 4d53d0acb391dd175087147204797ef0e9a8040c Mon Sep 17 00:00:00 2001
From: jbpenrath <jb.penrath@gmail.com>
Date: Tue, 26 Jan 2021 15:36:52 +0100
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8(pagetree)=20Page=20node=20can=20be=20?=
 =?UTF-8?q?foldable=20or=20not=20according=20to=20a=20limit?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add a setting `CMS_PAGETREE_DESCENDANTS_LIMIT` to define a limit of
descendants to allow a page node to be foldable or not. If this setting is not defined,
there is no descendants limit.
---
 cms/admin/pageadmin.py                             |  2 ++
 cms/static/cms/sass/components/pagetree/_tree.scss |  4 ++++
 cms/templates/admin/cms/page/tree/menu.html        |  9 +++++++--
 cms/utils/conf.py                                  |  1 +
 docs/reference/configuration.rst                   | 12 ++++++++++++
 5 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/cms/admin/pageadmin.py b/cms/admin/pageadmin.py
index cb522d923a5..921688110a3 100644
--- a/cms/admin/pageadmin.py
+++ b/cms/admin/pageadmin.py
@@ -1461,6 +1461,7 @@ def get_tree_rows(self, request, pages, language, root_pages, open_nodes=[]):
         is_popup = (IS_POPUP_VAR in request.POST or IS_POPUP_VAR in request.GET)
         languages = get_language_list(site.pk)
         user_can_add = page_permissions.user_can_add_subpage
+        descendants_limit = get_cms_setting('PAGETREE_DESCENDANTS_LIMIT')
 
         def render_page_row(page):
             page.title_cache = {trans.language: trans for trans in page.filtered_translations}
@@ -1486,6 +1487,7 @@ def render_page_row(page):
                 'node': page.node,
                 'ancestors': [node.item for node in page.node.get_cached_ancestors()],
                 'descendants': [node.item for node in page.node.get_cached_descendants()],
+                'follow_descendants': page.node.numchild <= descendants_limit,
                 'request': request,
                 'lang': language,
                 'metadata': metadata,
diff --git a/cms/static/cms/sass/components/pagetree/_tree.scss b/cms/static/cms/sass/components/pagetree/_tree.scss
index 078bfc4c8b8..e091590e7ee 100644
--- a/cms/static/cms/sass/components/pagetree/_tree.scss
+++ b/cms/static/cms/sass/components/pagetree/_tree.scss
@@ -857,6 +857,9 @@
     .jstree-closed > .jstree-ocl {
         @include icon(arrow-right);
     }
+    .jstree-unfoldable > .jstree-ocl {
+        @include icon(minus);
+    }
     .jstree-loading > .jstree-ocl {
         @include icon(loader);
         &:before {
@@ -905,6 +908,7 @@
     }
 
     .jstree-open,
+    .jstree-unfoldable,
     .jstree-closed,
     .jstree-loading {
         > .jstree-anchor {
diff --git a/cms/templates/admin/cms/page/tree/menu.html b/cms/templates/admin/cms/page/tree/menu.html
index e11783704a7..24b420b5a94 100644
--- a/cms/templates/admin/cms/page/tree/menu.html
+++ b/cms/templates/admin/cms/page/tree/menu.html
@@ -2,8 +2,13 @@
 
 {# INFO: columns are defined in base.html options #}
 {% spaceless %}
-<li class="cms-tree-node {{ css_class }}
-    {% if descendants %} jstree-open{% elif node.is_branch %} jstree-closed{% endif %}
+<li {% if not follow_descendants %}title="{% blocktrans %}There are too many descendants to unfold this page. Please search the page you are looking for.{% endblocktrans %}"{% endif %}class="cms-tree-node {{ css_class }}
+    {% spaceless %}
+    {% if follow_descendants %}
+        {% if descendants %} jstree-open{% elif node.is_branch %} jstree-closed{% endif %}
+    {% else %}
+        jstree-unfoldable
+    {% endif %}{% endspaceless %}
     {% if page.reverse_id == 'page_types' %} cms-tree-node-pagetype{% endif %}
     {% if node.depth == 0 %} cms-tree-node-top{% endif %}
     {% if filtered %} cms-tree-node-filtered{% endif %}
diff --git a/cms/utils/conf.py b/cms/utils/conf.py
index fabee4111d1..96cfbc9db87 100644
--- a/cms/utils/conf.py
+++ b/cms/utils/conf.py
@@ -74,6 +74,7 @@ def wrapper():
     'TOOLBAR_HIDE': False,
     'INTERNAL_IPS': [],
     'REQUEST_IP_RESOLVER': 'cms.utils.request_ip_resolvers.default_request_ip_resolver',
+    'PAGETREE_DESCENDANTS_LIMIT': float('inf'),
     'PAGE_WIZARD_DEFAULT_TEMPLATE': constants.TEMPLATE_INHERITANCE_MAGIC,
     'PAGE_WIZARD_CONTENT_PLUGIN': 'TextPlugin',
     'PAGE_WIZARD_CONTENT_PLUGIN_BODY': 'body',
diff --git a/docs/reference/configuration.rst b/docs/reference/configuration.rst
index 76d241fc660..c2f4603dbe0 100644
--- a/docs/reference/configuration.rst
+++ b/docs/reference/configuration.rst
@@ -1212,3 +1212,15 @@ default
 
 This indicates to the CMS that it should redirect requests with an non-lowercase
 slug to its lowercase version if no page with that slug is found.
+
+..  setting:: CMS_PAGETREE_DESCENDANTS_LIMIT
+
+PAGETREE_DESCENDANTS_LIMIT
+===================================
+
+default
+    ``float('inf')``
+
+A limit that prevents a node from being unfoldable if it contains too many
+descendants. This setting can be useful for sites with a very large tree
+structure to avoid performance drawbacks.