[TASK] Update mod.SHARED.colPos_list

The standard backend layout has only
one column since at least 8.7. According to the code in the Core the default value is empty.

Update the example removing outdated screenshots and use a backend layout defined via page TSconfig.

Releases: main, 13.4, 12.4

Documentation/PageTsconfig/Mod/Shared.rst

@@ -4,6 +4,7 @@
     mod; SHARED
     Modules; All
 ..  _pagesharedotionsformodules:
+..  _mod-shared:
 
 ======
 SHARED
@@ -23,61 +24,34 @@ colPos_list
 
 ..  confval:: colPos_list
     :name: mod-share-colPos-list
-    :type: list of integers
-    :Default: 1,0,2,3
+    :type: comma separated list of integers
+    :default: ''
+    :Path: mod.SHARED.colPos_list
 
-    This option lets you specify which columns of tt_content elements should be editable in the
-    'Columns' view of the Web > Page module.
+    This setting controls which areas or columns of the backend layouts are
+    editable. Columns configured in the :ref:`Backend Layout <backend-layouts>`,
+    which are not listed here, will be displayed with placeholder area.
 
-    Used on top of backend layouts, this setting controls which columns are editable. Columns configured
-    in the Backend Layout which are not listed here, will be displayed with placeholder area.
-
-    Each column has a number which ultimately comes from the configuration of the table tt_content,
-    field 'colPos'. These are the values of the four default columns used in the default backend layout:
-
-    Left: `1`, Normal: `0`, Right: `2`, Border: `3`
+    The default backend layout only has one column, which has the id 0.
 
 ..  _example_for_backend_layout:
 
-Example: Create a basic backend layout
---------------------------------------
-
-The example creates a basic backend layout and sets the "Left" column to be not editable:
-
-*   Create a record of type "Backend Layout", for instance in the root page of your website
-
-*   Add a title, e.g. "My Layout"
-
-*   Use the wizard to create a two column backend layout, the result may look like this:
-
-    ..  figure:: /Images/ManualScreenshots/List/SimpleBackendLayout.png
-        :alt: A simple backend layout
-
-        A simple backend layout
-
-*   Create a page and select this new backend layout in the "Appearance" tab.
-    The page module then looks like this, displaying the two defined columns:
-
-    ..  figure:: /Images/ManualScreenshots/Page/SimpleBackendLayoutInPageModule.png
-        :alt: Backend layout used in page module
-
-        Backend layout used in page module
-
-*   Now set the "Left" column to be not editable using page TSconfig in the
-    :guilabel:`Resources` tab of the page, by restricting `colPos_list` to
-    `0` (the "Content" columns as defined above):
+Example: Make a column in a backend layout not editable
+-------------------------------------------------------
 
-    ..  code-block:: typoscript
-        :caption: Page TSconfig in the "Resources" tab of the page
+Assuming the current page uses the following backend layout:
 
-        mod.SHARED.colPos_list = 0
+..  literalinclude:: /PageTsconfig/Mod/WebLayout/_BackendLayout.tsconfig
+    :caption: config/sites/my-site/page.tsconfig
 
-*   The result in the page module then looks like this:
+And we want to make the area "Jumbotron" (colPos = 1) not editable.
 
-    ..  figure:: /Images/ManualScreenshots/Page/SimpleBackendLayoutLeftNotEditable.png
-        :alt: One column not editable in a backend layout
+As long as :confval:`mod-share-colPos-list` is empty all areas are allowed.
+We therefore have to list all colPos, which should still be allowed. In this
+that would be the columns left (colPos = 0) and right (colPos = 2).
 
-        One column not editable in a backend layout
+..  literalinclude:: /PageTsconfig/Mod/_snippets/_mod.SHARED.colPos_list.tsconfig
+    :caption: config/sites/my-site/page.tsconfig
 
 ..  index::
     defaultLanguageFlag

Documentation/PageTsconfig/Mod/WebLayout/_BackendLayout.tsconfig

@@ -18,7 +18,7 @@ mod.web_layout.BackendLayouts {
                         }
                     }
 
-                    1 {
+                    2 {
                         columns {
                             1 {
                                 name = Left

Documentation/PageTsconfig/Mod/_snippets/_mod.SHARED.colPos_list.tsconfig

@@ -0,0 +1 @@
+mod.SHARED.colPos_list = 0,2