MDL-81180 core: Add support for array notation in hook callback

admin/tool/mobile/db/hooks.php

@@ -26,8 +26,8 @@ defined('MOODLE_INTERNAL') || die();
 
 $callbacks = [
     [
-        'hook' => core\hook\output\standard_head_html_prepend::class,
-        'callback' => 'tool_mobile\local\hooks\output\standard_head_html_prepend::callback',
+        'hook' => \core\hook\output\standard_head_html_prepend::class,
+        'callback' => [\tool_mobile\local\hooks\output\standard_head_html_prepend::class, 'callback'],
         'priority' => 0,
     ],
 ];

lib/classes/hook/manager.php

@@ -546,6 +546,13 @@ final class manager implements
             return null;
         }
         $classmethod = $callback['callback'];
+        if (is_array($classmethod)) {
+            if (count($classmethod) !== 2) {
+                debugging("Hook callback definition contains invalid 'callback' array in '$component'", DEBUG_DEVELOPER);
+                return null;
+            }
+            $classmethod = implode('::', $classmethod);
+        }
         if (!is_string($classmethod)) {
             debugging("Hook callback definition contains invalid 'callback' string in '$component'", DEBUG_DEVELOPER);
             return null;

lib/tests/fixtures/hook/hooks1_valid.php

@@ -28,6 +28,6 @@ defined('MOODLE_INTERNAL') || die();
 $callbacks = [
     [
         'hook' => 'test_plugin\\hook\\hook',
-        'callback' => 'test_plugin\\callbacks::test1',
+        'callback' => [\test_plugin\callbacks::class, 'test1'],
     ],
 ];