I installed a clean version of Magento 2.3.4 with composer and added a template. Then I wanted to edit some pages by inserting some XML code into the "Custom Layout XML" field that is visible in this screen:
But in my admin there is shown another field labeled "Custom Layout Update" not XML:
The help tooltip says
List of layout files with an update handle "selectable" matching
PageIdentifier_UpdateID. See Magento documentation for more information
But I can't find any information in the documentation and don't know how to enable the "Custom layout xml" field?
They go in app/design/frontend/<your_vendor_name>/<your_theme_name>/Magento_Cms/layout/
The file name should be like cms_page_view_selectable_<url-key>_<name>.xml
The name is just any name you want to give the layout. It will be used in the Custom Layout Update selection field in the Design section of the CMS Page edit page. But I noticed that, if the name is multiple words separated by "-" or "_" only the first word shows up in the selection box. So I'm naming them like "landingPage".
According to release note, now to manage custom layout updates we should do that by creating a physical files, my question is how to do that? It’s not clear for me how to manage PageIdentifier_UpdateID and where to put the file.
Thanks for your kindly help