Get layout name in front end - fluid typo3 - typo3

Question

I have a fluid typo3 site with single page layout.One menu have different layout.How to get the selected layout name in my main template?
main.html
<v:page.menu levels="1" as="sections">
<f:for each="{sections}" as="section" iteration="itemIteration">
<f:debug>{sections}</f:debug>
</f:for>
</v:page.menu>
sub.html
<f:layout name="Pagewithnav" />
<f:section name="Configuration">
<flux:form id="subnav" icon="{f:uri.resource(path: 'Icons/Page/logo.png')}" label="Sub Navigation">
<!-- Insert fields, sheets, grid, form section objects etc. here, in this flux:form tag -->
</flux:form>
<flux:grid>
<!-- Edit this grid to change the "backend layout" structure -->
<flux:grid.row>
<flux:grid.column colPos="0" colspan="4" name="main" label="Navigation wrapper" />
</flux:grid.row>
<flux:grid.row>
<flux:grid.column colPos="1" colspan="4" name="main" label="Main wrapper" />
</flux:grid.row>
</flux:grid>
</f:section>
<f:section name="Main">
<div class="sub_nav">
<div class="container">
<v:content.render column="0"/>
</div>
</div>
<div class="container">
<v:content.render column="1"/>
</div>
</f:section>

Answer 1

It depends on what exactly you mean by "Layout name":
If you mean fields of the pages table for each individual page then those will be available in each record when you iterate it in v:page.menu (for example, tx_fed_page_controller_action).
If you mean fields of pages but also when this variable is inherited (for example, backend_layout is and tx_fed_page_controller_action is as well, but each through different methods) it becomes more complex: you would need to walk through the root line and use the first non-empty value. For that, v:page.rootLine plus v:iterator.filter plus v:iterator.first can be of great help (put output from root line into filter to remove non-empty values then use the first VH to select the first value from that filtered result).
If you define this "layout" in a Flux form field on your page template it becomes a FlexForm variable which you can read with flux:form.data (with inheritance if not disabled and if templates match up through root line).
Depending on exactly which you mean there are quite a few possible solutions. If you are also looking for a recommendation about which one it makes sense to use: most likely you mean the layout you select in page properties (regardless of field) and for this, v:page.rootLine plus v:iterator.filter plus v:iterator.first is a nice and generic method to "slide select" any non-empty value from the root line of the current page.

Answer 2

You can get it with a variable in fluid
lib.templateName = TEXT
lib.templateName.stdWrap.cObject = CASE
lib.templateName.stdWrap {
cObject = TEXT
cObject {
data = levelfield:-2,backend_layout_next_level,slide
override.field = backend_layout
split {
token = pagets__
1.current = 1
1.wrap = |
}
}
ifEmpty = Default
}
page = PAGE
page.10 = FLUIDTEMPLATE
page.10 {
#...
variables.templateName < lib.templateName
}