MDL-81725 course: Get delegated section from cm_info

lib/modinfolib.php

@@ -93,6 +93,12 @@ class course_modinfo {
      */
     private $delegatedsections;
 
+    /**
+     * Index of sections delegated by course modules, indexed by course module instance.
+     * @var null|section_info[]
+     */
+    private ?array $delegatedbycm = null;
+
     /**
      * User ID
      * @var int
@@ -139,6 +145,7 @@ class course_modinfo {
         'cms' => 'get_cms',
         'instances' => 'get_instances',
         'groups' => 'get_groups_all',
+        'delegatedbycm' => 'get_sections_delegated_by_cm',
     );
 
     /**
@@ -410,6 +417,33 @@ class course_modinfo {
         return !empty($this->delegatedsections);
     }
 
+    /**
+     * Gets data about section delegated by course modules.
+     *
+     * @return section_info[] sections array indexed by course module ID
+     */
+    public function get_sections_delegated_by_cm(): array {
+        if (!is_null($this->delegatedbycm)) {
+            return $this->delegatedbycm;
+        }
+        $this->delegatedbycm = [];
+        foreach ($this->delegatedsections as $componentsections) {
+            foreach ($componentsections as $section) {
+                $delegateinstance = $section->get_component_instance();
+                // We only return sections delegated by course modules. Sections delegated to other
+                // types of components must implement their own methods to get the section.
+                if (!$delegateinstance || !($delegateinstance instanceof \core_courseformat\sectiondelegatemodule)) {
+                    continue;
+                }
+                if (!$cm = $delegateinstance->get_cm()) {
+                    continue;
+                }
+                $this->delegatedbycm[$cm->id] = $section;
+            }
+        }
+        return $this->delegatedbycm;
+    }
+
     /**
      * Static cache for generated course_modinfo instances
      *
@@ -2171,6 +2205,19 @@ class cm_info implements IteratorAggregate {
         return $cmrecord;
     }
 
+    /**
+     * Returns the section delegated by this module, if any.
+     *
+     * @return ?section_info
+     */
+    public function get_delegated_section_info(): ?section_info {
+        $delegatedsections = $this->modinfo->get_sections_delegated_by_cm();
+        if (!array_key_exists($this->id, $delegatedsections)) {
+            return null;
+        }
+        return $delegatedsections[$this->id];
+    }
+
     // Set functions
     ////////////////