API Move logic from silverstripe/cms into central place

This logic is used by CMSMain but needs to be callable on any
hierarchical model.

In some cases this logic is generic enough it could be on any model or
any DataObject

src/Model/ModelData.php

@@ -74,6 +74,8 @@ class ModelData
 
     private array $objCache = [];
 
+    private $_cache_statusFlags = null;
+
     public function __construct()
     {
         // no-op
@@ -487,6 +489,31 @@ public function hasValue(string $field, array $arguments = [], bool $cache = tru
 
     // UTILITY METHODS -------------------------------------------------------------------------------------------------
 
+    /**
+     * Flags provides the user with additional data about the current page status.
+     *
+     * Mostly this is used for versioning, but can be used for other purposes (e.g. localisation).
+     * Each page can have more than one status flag.
+     *
+     * Returns an associative array of a unique key to a (localized) title for the flag.
+     * The unique key can be reused as a CSS class.
+     *
+     * Example (simple):
+     *   "deletedonlive" => "Deleted"
+     *
+     * Example (with optional title attribute):
+     *   "deletedonlive" => ['text' => "Deleted", 'title' => 'This page has been deleted']
+     */
+    public function getStatusFlags(bool $cached = true): array
+    {
+        if (!$this->_cache_statusFlags || !$cached) {
+            $flags = [];
+            $this->extend('updateStatusFlags', $flags);
+            $this->_cache_statusFlags = $flags;
+        }
+        return $this->_cache_statusFlags;
+    }
+
     /**
      * Find appropriate templates for SSViewer to use to render this object
      */
@@ -545,6 +572,17 @@ public function Debug(): ModelData|string
         return ModelDataDebugger::create($this);
     }
 
+    /**
+     * Clears record-specific cached data.
+     */
+    public function flushCache(): static
+    {
+        $this->objCacheClear();
+        $this->_cache_statusFlags = null;
+        $this->extend('onFlushCache');
+        return $this;
+    }
+
     /**
      * Generate the cache name for a field
      */

src/ORM/DataObject.php

@@ -116,17 +116,22 @@ class DataObject extends ModelData implements DataObjectInterface, i18nEntityPro
 {
     /**
      * Human-readable singular name.
-     * @var string
-     * @config
      */
-    private static $singular_name = null;
+    private static ?string $singular_name = null;
 
     /**
      * Human-readable plural name
-     * @var string
-     * @config
      */
-    private static $plural_name = null;
+    private static ?string $plural_name = null;
+
+    /**
+     * Description of the class.
+     * Unlike most configuration, this is usually used uninherited, meaning it should be defined
+     * on each subclass.
+     *
+     * Used in some areas of the CMS, e.g. when selecting what type of record to create.
+     */
+    private static ?string $class_description = null;
 
     /**
      * @config
@@ -141,7 +146,6 @@ class DataObject extends ModelData implements DataObjectInterface, i18nEntityPro
      * @var string
      */
     private static $default_classname = null;
-
     /**
      * Whether this DataObject class must only use the primary database and not a read-only replica
      * Note that this will be only be enforced when using DataQuery::execute() or
@@ -946,6 +950,27 @@ public function i18n_plural_name()
         return _t(static::class . '.PLURALNAME', $this->plural_name());
     }
 
+    /**
+     * Get description for this class
+     */
+    public function classDescription(): ?string
+    {
+        return static::config()->get('class_description', Config::UNINHERITED);
+    }
+
+    /**
+     * Get localised description for this class
+     */
+    public function i18nClassDescription(): ?string
+    {
+        $placeholder = 'PLACEHOLDER_DESCRIPTION';
+        $description = _t(static::class.'.CLASS_DESCRIPTION', $this->classDescription() ?? $placeholder);
+        if ($description === $placeholder) {
+            return null;
+        }
+        return $description;
+    }
+
     /**
      * Standard implementation of a title/label for a specific
      * record. Tries to find properties 'Title' or 'Name',
@@ -3515,14 +3540,14 @@ public static function get_one($callerClass = null, $filter = "", $cache = true,
     }
 
     /**
-     * Flush the cached results for all relations (has_one, has_many, many_many)
-     * Also clears any cached aggregate data.
+     * @inheritDoc
+     *
+     * Also flush the cached results for all relations (has_one, has_many, many_many)
      *
-     * @param boolean $persistent When true will also clear persistent data stored in the Cache system.
+     * @param bool $persistent When true will also clear persistent data stored in the Cache system.
      *                            When false will just clear session-local cached data
-     * @return static $this
      */
-    public function flushCache($persistent = true)
+    public function flushCache(bool $persistent = true): static
     {
         if (static::class == DataObject::class) {
             DataObject::$_cache_get_one = [];
@@ -3536,11 +3561,9 @@ public function flushCache($persistent = true)
             }
         }
 
-        $this->extend('onFlushCache');
-
         $this->components = [];
         $this->eagerLoadedData = [];
-        return $this;
+        return parent::flushCache();
     }
 
     /**
@@ -3567,7 +3590,7 @@ public static function flush_and_destroy_cache()
      */
     public static function reset()
     {
-        DBEnum::flushCache();
+        DBEnum::reset();
         ClassInfo::reset_db_cache();
         static::getSchema()->reset();
         DataObject::$_cache_get_one = [];

src/ORM/FieldType/DBEnum.php

@@ -8,6 +8,7 @@
 use SilverStripe\Forms\FormField;
 use SilverStripe\Forms\SelectField;
 use SilverStripe\Core\ArrayLib;
+use SilverStripe\Core\Resettable;
 use SilverStripe\ORM\Connect\MySQLDatabase;
 use SilverStripe\ORM\DB;
 use SilverStripe\Model\ModelData;
@@ -17,7 +18,7 @@
  *
  * See {@link DropdownField} for a {@link FormField} to select enum values.
  */
-class DBEnum extends DBString
+class DBEnum extends DBString implements Resettable
 {
     private static array $field_validators = [
         OptionFieldValidator::class => ['getEnum'],
@@ -44,7 +45,7 @@ class DBEnum extends DBString
     /**
      * Clear all cached enum values.
      */
-    public static function flushCache(): void
+    public static function reset(): void
     {
         DBEnum::$enum_cache = [];
     }
@@ -182,7 +183,7 @@ public function getEnum(): array
      * If table or name are not set, or if it is not a valid field on the given table,
      * then only known enum values are returned.
      *
-     * Values cached in this method can be cleared via `DBEnum::flushCache();`
+     * Values cached in this method can be cleared via `DBEnum::reset();`
      */
     public function getEnumObsolete(): array
     {