Add ability to identify a link to the current page

A new MenuItem boolean property is available, $is_active:
- its value is true if the link points to the current page
- its value is false otherwise

MenuItem.php

@@ -5,6 +5,11 @@ namespace dokuwiki\plugin\childrenpages;
 use dokuwiki\Menu\Item\AbstractItem;
 
 class MenuItem extends AbstractItem {
+	/**
+	 * @var bool $is_active True if it is a link to the current page
+	 */
+	public bool $is_active;
+
 	/**
 	 * Generate a menu item from a passed string
 	 *
@@ -24,6 +29,7 @@ class MenuItem extends AbstractItem {
 		$this->label = $label;
 		parent::__construct();
 		$this->setTargetFromType($type, $strip_namespace);
+		$this->setIsActive();
 	}
 
 	/**
@@ -69,6 +75,16 @@ class MenuItem extends AbstractItem {
 		$this->params = [];
 	}
 
+	/**
+	 * Set the active status of the link
+	 */
+	protected function setIsActive() : void {
+		global $INFO;
+		$current_page_id = $INFO['id'];
+		$target_page_id = $this->id;
+		$this->is_active = ( $target_page_id === $current_page_id );
+	}
+
 	/**
 	 * Convenience method to get the attributes for constructing an <a> element
 	 * Parent method is declared in dokuwiki\Menu\Item\AbstractItem