Layout snippets do not work from within other layout snippets

[JojOatXGME]

Description

When I use a layout snippet within another layout snipped, the content is discarded without any error reported.

Expected behavior

I would expect to see the content of the included snippet.

Note

Since I found a workaround, the issue is not really important to me. However, I was a bit lost initially when I got an empty page without any error. I thought I should let you know anyway.

To reproduce

1. Create a snippet
2. Create another snippet which uses the previous snipped as a layout snippet
3. Create a template which uses the snipped from step 2 as a layout snippet
4. Content of the snipped from step 1 is missing

Example

In the following example, I get a HTTP 200 response, but the page is completely empty.

JojOatXGME/plainkit@5798fca

Alternative: patch on top of plainkit (based on commit 3d651f772485fa7ec836238bde103d4368e9fdcb)

$ git diff --staged
diff --git a/site/snippets/base.php b/site/snippets/base.php
new file mode 100644
index 0000000..74e38ae
--- /dev/null
+++ b/site/snippets/base.php
@@ -0,0 +1 @@
+<h1><?= $page->title() ?></h1>
diff --git a/site/snippets/subsnippet.php b/site/snippets/subsnippet.php
new file mode 100644
index 0000000..b95c82b
--- /dev/null
+++ b/site/snippets/subsnippet.php
@@ -0,0 +1 @@
+<?php snippet('base', slots: true);
diff --git a/site/templates/default.php b/site/templates/default.php
index 74e38ae..9ca23b8 100644
--- a/site/templates/default.php
+++ b/site/templates/default.php
@@ -1 +1 @@
-<h1><?= $page->title() ?></h1>
+<?php snippet('subsnippet', slots: true);

Your setup

Kirby Version
4.8.0

Console output

> Composer\Config::disableProcessTimeout
> @php -S localhost:8000 kirby/router.php
[Mon Aug 25 01:15:56 2025] PHP 8.4.11 Development Server (http://localhost:8000) started
[Mon Aug 25 01:16:02 2025] [::1]:54971 Accepted
[Mon Aug 25 01:16:02 2025] [::1]:54971 Closing

Your system (please complete the following information)

• Device: Desktop
• OS: Windows 10
• Browser: Firefox
• Version: 142.0

Workaround

Call endsnippet() at the end of either the snippet of step 2, or the template of step 3.

[afbora]

kirby/src/Template/Template.php

Lines 166 to 179 in c9708e5

	// if last `endsnippet()` inside the current template
	// has been omitted (= snippet was used as layout snippet),
	// `Snippet::$current` will point to a snippet that was
	// opened inside the template; if that snippet is the direct
	// child of the snippet that was open before the template was
	// rendered (which could be `null` if no snippet was open),
	// take the buffer output from the template as default slot
	// and render the snippet as final template output
	if (
	Snippet::$current === null ||
	Snippet::$current->parent() !== $snippet
	) {
	return $template;
	}

The code clearly states why this won't work.

A solution in core might be to check the parent chain to see if it has any children.

[JojOatXGME]

@afbora If this is the only place handling layout snippets, it looks like layout snippets are not really implemented inside other snippets. Is this a bug or intentional? If this is intentional, it should probably be documented more explicitly at Layout snippets. Otherwise, I created #7571 to implement layout snippets within other snippets.