Nested sections rendering (#4622)

* Fix: Nested sections rendering

* Changed UG and applied PR suggestions

Author: iRedds

system/View/View.php

@@ -109,6 +109,7 @@ class View implements RendererInterface
 	 */
 	protected $layout;
 
+
 	/**
 	 * Holds the sections and their data.
 	 *
@@ -121,9 +122,18 @@ class View implements RendererInterface
 	 * if any.
 	 *
 	 * @var string|null
+	 * @deprecated
 	 */
 	protected $currentSection;
 
+	/**
+	 * The name of the current section being rendered,
+	 * if any.
+	 *
+	 * @var array<string>
+	 */
+	protected $sectionStack = [];
+
 	/**
 	 * Constructor
 	 *
@@ -227,7 +237,7 @@ public function render(string $view, array $options = null, bool $saveData = nul
 		// When using layouts, the data has already been stored
 		// in $this->sections, and no other valid output
 		// is allowed in $output so we'll overwrite it.
-		if (! is_null($this->layout) && empty($this->currentSection))
+		if (! is_null($this->layout) && $this->sectionStack === [])
 		{
 			$layoutView   = $this->layout;
 			$this->layout = null;
@@ -402,35 +412,44 @@ public function extend(string $layout)
 	/**
 	 * Starts holds content for a section within the layout.
 	 *
-	 * @param string $name
+	 * @param string $name Section name
+	 *
+	 * @return void
+	 *
 	 */
 	public function section(string $name)
 	{
+		//Saved to prevent BC.
 		$this->currentSection = $name;
+		$this->sectionStack[] = $name;
 
 		ob_start();
 	}
 
 	/**
+	 * Captures the last section
+	 *
+	 * @return void
 	 * @throws RuntimeException
 	 */
 	public function endSection()
 	{
 		$contents = ob_get_clean();
 
-		if (empty($this->currentSection))
+		if ($this->sectionStack === [])
 		{
 			throw new RuntimeException('View themes, no current section.');
 		}
 
+		$section = array_pop($this->sectionStack);
+
 		// Ensure an array exists so we can store multiple entries for this.
-		if (! array_key_exists($this->currentSection, $this->sections))
+		if (! array_key_exists($section, $this->sections))
 		{
-			$this->sections[$this->currentSection] = [];
+			$this->sections[$section] = [];
 		}
-		$this->sections[$this->currentSection][] = $contents;
 
-		$this->currentSection = null;
+		$this->sections[$section][] = $contents;
 	}
 
 	/**

tests/system/View/ViewTest.php

@@ -367,7 +367,7 @@ public function testRenderSaveDataCover()
 		$this->assertEquals(true, $this->getPrivateProperty($view, 'saveData'));
 	}
 
-	public function testRenderSaveDataUseAflterSaveDataFalse()
+	public function testRenderSaveDataUseAfterSaveDataFalse()
 	{
 		$view = new View($this->config, $this->viewsDir, $this->loader);
 		$view->setVar('testString', 'test');
@@ -387,4 +387,17 @@ public function testCachedAutoDiscoverAndRender()
 		// this second renderings should go thru the cache
 		$this->assertStringContainsString($expected, $view->render('Nested/simple', ['cache' => 10]));
 	}
+
+	public function testRenderNestedSections()
+	{
+		$view = new View($this->config, $this->viewsDir, $this->loader);
+
+		$view->setVar('testString', 'Hello World');
+
+		$content = $view->render('nested_section');
+
+		$this->assertStringContainsString('<p>First</p>', $content);
+		$this->assertStringContainsString('<p>Second</p>', $content);
+		$this->assertStringContainsString('<p>Third</p>', $content);
+	}
 }

tests/system/View/Views/nested_section.php

@@ -0,0 +1,14 @@
+<?php $this->extend('layout'); ?>
+
+<?php $this->section('content'); ?>
+<p>Second</p>
+
+    <?php $this->section('content'); ?>
+    <p>First</p>
+    <?php $this->endSection(); ?>
+
+<?php $this->endSection(); ?>
+
+<?php $this->section('content'); ?>
+<p>Third</p>
+<?php $this->endSection(); ?>

user_guide_src/source/changelogs/v4.1.2.rst

@@ -16,6 +16,7 @@ Enhancements:
 
 Changes:
 
+- Layouts in views now support nested sections.
 - ``Response::getCookie`` now returns a ``Cookie`` instance instead of an array of cookie attributes.
 - ``Response::getCookies`` now returns an array of ``Cookie`` instances instead of array of array of attributes.
 - To eliminate warnings from modern browsers' consoles, empty samesite values will be defaulted to ``Lax`` on cookie dispatch.
@@ -30,6 +31,7 @@ Changes:
 
 Deprecations:
 
+- Deprecated ``Codeigniter\View\View::$currentSection`` property.
 - Language strings and exceptions on invalid cookie samesite are deprecated for the ``CookieException``'s own exception message.
 - Deprecated `CodeIgniter\Entity` in favor of `CodeIgniter\Entity\Entity`
 - Deprecated cookie-related properties of ``Response`` in order to use the ``Cookie`` class.

user_guide_src/source/outgoing/view_layouts.rst

@@ -60,6 +60,18 @@ matches the section name exists.::
 
 The ``endSection()`` does not need the section name. It automatically knows which one to close.
 
+Sections can contain nested sections::
+
+    <?= $this->extend('default') ?>
+
+    <?= $this->section('content') ?>
+        <h1>Hello World!</h1>
+        <?= $this->section('javascript') ?>
+           let a = 'a';
+        <?= $this->endSection() ?>
+    <?= $this->endSection() ?>
+
+
 ******************
 Rendering the View
 ******************