typoscript backend_layout_next_level not working - typo3

Question

I have the following config
page = PAGE
page {
typeNum = 0
10 = FLUIDTEMPLATE
10 {
templateRootPath = EXT:folder/Resources/Private/Website/Templates/
partialRootPath = EXT:folder/Resources/Private/Website/Partials/
layoutRootPath = EXT:folder/Resources/Private/Website/Layout/
file.stdWrap.cObject = CASE
file.stdWrap.cObject {
key.data = levelfield:-1, backend_layout_next_level, slide
key.override.field = backend_layout
default = TEXT
default.value = whatever.html
1 < .default
2 = TEXT
2.value = whatever-else.html
}
}
Somehow the 'backend_layout_next_level' is not working; it is not sliding down the tree. As a result I have to set a backend_layout for each page which is not what one should expect.
Is there a way of knowing/debugging/finding out what's causing this? I thought it might be something related to a curly brace being in the wrong place (too early, too late or just plain wrong) inside my typoscript. Therefor I looked inside the Typoscript Template Analyzer and found some errors which I've fixed, but the problem still persists.
Thanks already!
Best regards

Answer 1

You use have to give the full path to the file as a value in the .file property or you should use .templateName instead and only provide the name (case sensitive!!!) of the template file without suffix.
#see https://docs.typo3.org/typo3cms/TyposcriptReference/ContentObjects/Fluidtemplate/Index.html
Note that in your current setting, the uid of the template record must be 1 or 2.
And you can try to use levelfield: -2 instead of levelfield: -1.

Answer 2

TBH I never understood this #^$#% CASE syntax... Therefore definitely prefer common condition which works perfect, you must to add custom condition like I showed in other post, so you can use it like:
page {
typeNum = 0
10 = FLUIDTEMPLATE
10 {
templateRootPath = EXT:folder/Resources/Private/Website/Templates/
partialRootPath = EXT:folder/Resources/Private/Website/Partials/
layoutRootPath = EXT:folder/Resources/Private/Website/Layout/
file = whatever.html
}
}
[userFunc = user_beLayout(2)]
page.10.file = whatever-else.html
[userFunc = user_beLayout(3)]
page.10.file = yet-other.html
[userFunc = user_beLayout(4)]
page.10.file = etc.html
[end]
Edit - to satisfy some comments
Note: When I say that I don't understand CASE syntax, that doesn't mean that I don't know it... especially that I studied it in details not once, here's the conclusion...
About performance:
Custom conditions solution is faster than using CASE and slide combination as it doesn't involve additional DB queries (slide does), it iterates $GLOBALS['TSFE']->page array, which is already collected, and stops further checks ASAP, so it's cheaper than slide which makes additional queries if it finds slide in TS (doesn't matter if it's required or not) - (examine the code for slide mechanics), so actually conditions are performance-saver not killer :)
Yet more
Using conditions blocks you can change behavior of multiple elements at once (instead writing separate CASE for each) i.e.:
[userFunc = user_beLayout(2)]
page.10.file = whatever-else.html
lib.genericMenu >
config.absRefPrefix = /layout-specific-abs/
// etc...
[end]
Using CASE syntax you'll need to repeat all these checks for each element... (where's DRY?)
Finally
Both solutions are ... usable especially when using with cached pages, (difference between them will be about teens or maybe in drastic situation hundred milliseconds -conditions will be faster), for uncached pages most probably it will be good idea to set be_layout directly for each pages record in both cases.

Answer 3

It is quite some time ago, you probably resolved your issue but here is a working approach:
page = PAGE
page {
10 = FLUIDTEMPLATE
10 {
# select different html files for layouts - ref: backend_layout
file.stdWrap.cObject = TEXT
file.stdWrap.cObject {
data = levelfield:-2,backend_layout_next_level,slide
override.field = backend_layout
split {
token = pagets__
1.current = 1
1.wrap = |
}
wrap = EXT:folder/Resources/Private/Templates/|.html
}
layoutRootPath = EXT:folder/Resources/Private/Layouts/
partialRootPath = EXT:folder/Resources/Private/Partials/
}
}
or you can pass it as a variable:
page = PAGE
page {
10 = FLUIDTEMPLATE
10 {
file = EXT:folder/Resources/Private/Templates/Main.html
layoutRootPath = EXT:folder/Resources/Private/Layouts/
partialRootPath = EXT:folder/Resources/Private/Partials/
variables {
# BE_Layout
BE_Layout = COA
BE_Layout {
stdWrap.cObject = TEXT
stdWrap.cObject {
data = levelfield:-2,backend_layout_next_level,slide
override.field = backend_layout
split {
token = pagets__
1.current = 1
1.wrap = |
}
wrap = |.html
}
}
}
}