frontend-plugin-api: move extension instance creation to frontend-app-api

Co-authored-by: Fredrik Adelöw <freben@gmail.com>
Co-authored-by: Johan Haals <johan.haals@gmail.com>
Co-authored-by: Vincenzo Scamporlino <vincenzos@spotify.com>
Co-authored-by: Philipp Hugenroth <philipph@spotify.com>
Co-authored-by: Camila Belo <camilaibs@gmail.com>
Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/frontend-app-api/package.json

@@ -32,10 +32,11 @@
   "dependencies": {
     "@backstage/config": "workspace:^",
     "@backstage/frontend-plugin-api": "workspace:^",
-    "@backstage/plugin-graphiql": "workspace:^"
+    "@backstage/plugin-graphiql": "workspace:^",
+    "lodash": "^4.17.21"
   },
   "peerDependencies": {
-    "react": "*",
-    "react-router-dom": "*"
+    "react": "^16.13.1 || ^17.0.0",
+    "react-router-dom": "6.0.0-beta.0 || ^6.3.0"
   }
 }

packages/frontend-app-api/src/createApp.tsx

@@ -19,11 +19,13 @@ import { Config, ConfigReader } from '@backstage/config';
 import {
   ExtensionInstanceConfig,
   BackstagePlugin,
-  ExtensionInstance,
-  createExtensionInstance,
   coreExtensionData,
 } from '@backstage/frontend-plugin-api';
 import { RouteExtension } from './extensions/RouteExtension';
+import {
+  createExtensionInstance,
+  ExtensionInstance,
+} from './createExtensionInstance';
 
 // Since we'll never merge arrays in config the config reader context
 // isn't too much of a help. Fall back to manual config reading logic

packages/frontend-app-api/src/createExtensionInstance.ts

@@ -0,0 +1,52 @@
+/*
+ * 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 { Extension } from '@backstage/frontend-plugin-api';
+import mapValues from 'lodash/mapValues';
+
+/** @internal */
+export interface ExtensionInstance {
+  id: string;
+  data: Map<string, unknown>;
+  $$type: 'extension-instance';
+}
+
+/** @internal */
+export function createExtensionInstance(options: {
+  id: string;
+  extension: Extension;
+  config: unknown;
+  attachments: Record<string, ExtensionInstance[]>;
+}): ExtensionInstance {
+  const { extension, config, attachments } = options;
+  const extensionData = new Map<string, unknown>();
+  extension.factory({
+    config,
+    bind: mapValues(extension.output, ref => {
+      return (value: unknown) => extensionData.set(ref.id, value);
+    }),
+    inputs: mapValues(
+      extension.inputs,
+      ({ extensionData: pointData }, inputName) => {
+        // TODO: validation
+        return (attachments[inputName] ?? []).map(attachment =>
+          mapValues(pointData, ref => attachment.data.get(ref.id)),
+        );
+      },
+    ),
+  });
+  return { id: options.id, data: extensionData, $$type: 'extension-instance' };
+}