chore: hook to get the field extensions

Signed-off-by: blam <ben@blam.sh>

plugins/scaffolder-react/src/api/ref.ts

@@ -16,8 +16,13 @@
 
 import { createApiRef } from '@backstage/core-plugin-api';
 import { ScaffolderApi } from './types';
+import { getOrCreateGlobalSingleton } from '@backstage/version-bridge';
 
 /** @public */
-export const scaffolderApiRef = createApiRef<ScaffolderApi>({
-  id: 'plugin.scaffolder.service',
-});
+export const scaffolderApiRef = getOrCreateGlobalSingleton(
+  'scaffolder:scaffolder-api-ref',
+  () =>
+    createApiRef<ScaffolderApi>({
+      id: 'plugin.scaffolder.service',
+    }),
+);

plugins/scaffolder-react/src/extensions/index.tsx

@@ -22,17 +22,7 @@ import {
   FieldExtensionComponentProps,
 } from './types';
 import { Extension, attachComponentData } from '@backstage/core-plugin-api';
-
-/**
- * The key used to store the field extension data for the `<ScaffolderFieldExtensions />` component
- * @public
- */
-export const FIELD_EXTENSION_WRAPPER_KEY = 'scaffolder.extensions.wrapper.v1';
-/**
- * The key used to store the field extension data for any `<FieldExtension />` component
- * @public
- */
-export const FIELD_EXTENSION_KEY = 'scaffolder.extensions.field.v1';
+import { FIELD_EXTENSION_KEY, FIELD_EXTENSION_WRAPPER_KEY } from './keys';
 
 /**
  * A type used to wrap up the FieldExtension to embed the ReturnValue and the InputProps

plugins/scaffolder-react/src/extensions/keys.ts

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export const FIELD_EXTENSION_WRAPPER_KEY = 'scaffolder.extensions.wrapper.v1';
+/**
+ * The key used to store the field extension data for any `<FieldExtension />` component
+ */
+export const FIELD_EXTENSION_KEY = 'scaffolder.extensions.field.v1';

plugins/scaffolder-react/src/hooks/index.ts

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export { useCustomFieldExtensions } from './useCustomFieldExtensions';

plugins/scaffolder-react/src/hooks/useCustomFieldExtensions.ts

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { useElementFilter } from '@backstage/core-plugin-api';
+import { FieldExtensionOptions } from '../extensions';
+import {
+  FIELD_EXTENSION_KEY,
+  FIELD_EXTENSION_WRAPPER_KEY,
+} from '../extensions/keys';
+import { NextFieldExtensionOptions } from '../next';
+
+/**
+ * Hook that returns all custom field extensions from the current outlet.
+ * @public
+ */
+export const useCustomFieldExtensions = (outlet: React.ReactNode) => {
+  return useElementFilter(outlet, elements =>
+    elements
+      .selectByComponentData({
+        key: FIELD_EXTENSION_WRAPPER_KEY,
+      })
+      .findComponentData<FieldExtensionOptions | NextFieldExtensionOptions>({
+        key: FIELD_EXTENSION_KEY,
+      }),
+  );
+};

plugins/scaffolder-react/src/index.ts

@@ -18,5 +18,6 @@ export * from './extensions';
 export * from './types';
 export * from './secrets';
 export * from './api';
+export * from './hooks';
 
 export * from './next';