afform_tags - use Tag entity rather than option group

ext/afform/admin/Civi/AfformAdmin/AfformAdminMeta.php

@@ -19,12 +19,7 @@ public static function getAdminSettings() {
       ->addWhere('option_group_id:name', '=', 'afform_placement')
       ->addOrderBy('weight')
       ->execute(), 'label', 'value');
-    $afformTags = \CRM_Utils_Array::formatForSelect2((array) \Civi\Api4\OptionValue::get(FALSE)
-      ->addSelect('value', 'label', 'icon', 'description')
-      ->addWhere('is_active', '=', TRUE)
-      ->addWhere('option_group_id:name', '=', 'afform_tags')
-      ->addOrderBy('weight')
-      ->execute(), 'label', 'value');
+    $afformTags = \CRM_Utils_Array::formatForSelect2((array) \Civi\Api4\Utils\AfformTags::getTagOptions());
     $afformTypes = (array) \Civi\Api4\OptionValue::get(FALSE)
       ->addSelect('name', 'label', 'icon')
       ->addWhere('is_active', '=', TRUE)

ext/afform/core/Civi/Api4/Afform.php

@@ -187,7 +187,9 @@ public static function getFields($checkPermissions = TRUE) {
         [
           'name' => 'tags',
           'title' => E::ts('Tags'),
-          'pseudoconstant' => ['optionGroupName' => 'afform_tags'],
+          'pseudoconstant' => [
+            'callback' => [Utils\AfformTags::class, 'getTagOptions'],
+          ],
           'data_type' => 'Array',
           'input_type' => 'Select',
         ],

ext/afform/core/Civi/Api4/Utils/AfformTags.php

@@ -0,0 +1,33 @@
+<?php
+namespace Civi\Api4\Utils;
+
+/**
+ * Class AfformTags
+ * @package Civi\Api4\Utils
+ *
+ * Utils for managing the tags field on Afforms
+ *
+ */
+class AfformTags {
+
+  /**
+   * @return array
+   */
+  public static function getTagOptions(): array {
+    $tagRecords = (array) \Civi\Api4\Tag::get(FALSE)
+      ->addSelect('name', 'label', 'description', 'color')
+      ->addWhere('used_for', 'CONTAINS', 'Afform')
+      ->addWhere('is_selectable', '=', TRUE)
+      ->execute();
+
+    $tagOptions = [];
+
+    // prefer tag names to keys for portability
+    foreach ($tagRecords as $record) {
+      $record['id'] = $record['name'];
+      $tagOptions[] = $record;
+    }
+
+    return $tagOptions;
+  }
+}

ext/afform/core/managed/AfformTags.mgd.php

@@ -2,49 +2,52 @@
 
 use CRM_Afform_ExtensionUtil as E;
 
-// Option group for Afform.tags field
+// This file:
+// - adds option value to `tag_used_for`, allowing Afforms to be tagged
+//   NOTE: this is unusual in that afform is not a db entity
+//   (normally the value normally corresponds to a physical table name in the
+//   database - here it is just the entity name)
+//
+// - creates an example tag that can be used for afforms. This is more to demonstrate
+//   how it can be used, as Donor Journey might be useful for some orgs but not for others
+//   @todo think of better example tag that is more universally applicable?
 return [
   [
-    'name' => 'AfformTags',
-    'entity' => 'OptionGroup',
-    'update' => 'always',
+    'name' => 'AfformTags:tag_used_for',
+    'entity' => 'OptionValue',
     'cleanup' => 'always',
+    'update' => 'always',
     'params' => [
       'version' => 4,
       'values' => [
-        'name' => 'afform_tags',
-        'title' => E::ts('Afform Tags'),
-        'is_reserved' => TRUE,
+        'option_group_id.name' => 'tag_used_for',
+        'value' => 'Afform',
+        'name' => 'Afform',
+        'label' => E::ts('Afforms'),
+        'is_reserved' => FALSE,
         'is_active' => TRUE,
-        'option_value_fields' => [
-          'name',
-          'label',
-          'icon',
-          'description',
-          'color',
-        ],
+        'domain_id' => NULL,
       ],
-      'match' => ['name'],
+      'match' => ['option_group_id', 'name'],
     ],
   ],
   [
     'name' => 'AfformTags:donor_journey',
-    'entity' => 'OptionValue',
+    'entity' => 'Tag',
     'cleanup' => 'unused',
     'update' => 'unmodified',
     'params' => [
       'version' => 4,
       'values' => [
-        'option_group_id.name' => 'afform_tags',
         'name' => 'donor_journey',
-        'value' => 'donor_journey',
+        'tag_used_for' => ['afform'],
         'label' => E::ts('Donor Journey'),
         'is_reserved' => FALSE,
         'is_active' => TRUE,
         'icon' => 'fa-coins',
         'description' => E::ts('Forms relating to donor journey.'),
       ],
-      'match' => ['option_group_id', 'name'],
+      'match' => ['name'],
     ],
   ],
 ];