From 221293e22d0089c4486f18dd48e5fa6828021884 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Fri, 17 Nov 2023 16:30:36 +0100
Subject: [PATCH] frontend-*-api: initial ComponentsApi implementation
MIME-Version: 1.0
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Co-authored-by: Fredrik Adelöw <freben@gmail.com>
Co-authored-by: Camila Belo <camilaibs@gmail.com>
Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .../ComponentsApi/ComponentsApi.ts            | 34 +++++++++++++++++
 .../implementations/ComponentsApi/index.ts    | 17 +++++++++
 .../src/apis/definitions/ComponentsApi.ts     | 37 +++++++++++++++++++
 .../src/apis/definitions/index.ts             |  1 +
 4 files changed, 89 insertions(+)
 create mode 100644 packages/frontend-app-api/src/apis/implementations/ComponentsApi/ComponentsApi.ts
 create mode 100644 packages/frontend-app-api/src/apis/implementations/ComponentsApi/index.ts
 create mode 100644 packages/frontend-plugin-api/src/apis/definitions/ComponentsApi.ts

diff --git a/packages/frontend-app-api/src/apis/implementations/ComponentsApi/ComponentsApi.ts b/packages/frontend-app-api/src/apis/implementations/ComponentsApi/ComponentsApi.ts
new file mode 100644
index 0000000000..87a12d136e
--- /dev/null
+++ b/packages/frontend-app-api/src/apis/implementations/ComponentsApi/ComponentsApi.ts
@@ -0,0 +1,34 @@
+/*
+ * 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 { ComponentRef, ComponentsApi } from '@backstage/frontend-plugin-api';
+
+/**
+ * Implementation for the {@linkComponentApi}
+ *
+ * @internal
+ */
+export class DefaultComponentsApi implements ComponentsApi {
+  #components: Map<ComponentRef<any>, any>;
+
+  constructor(components: Map<ComponentRef<any>, any>) {
+    this.#components = components;
+  }
+
+  getComponent<T>(ref: ComponentRef<T>): T | undefined {
+    return this.#components.get(ref);
+  }
+}
diff --git a/packages/frontend-app-api/src/apis/implementations/ComponentsApi/index.ts b/packages/frontend-app-api/src/apis/implementations/ComponentsApi/index.ts
new file mode 100644
index 0000000000..f04059c54f
--- /dev/null
+++ b/packages/frontend-app-api/src/apis/implementations/ComponentsApi/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 { DefaultComponentsApi } from './ComponentsApi';
diff --git a/packages/frontend-plugin-api/src/apis/definitions/ComponentsApi.ts b/packages/frontend-plugin-api/src/apis/definitions/ComponentsApi.ts
new file mode 100644
index 0000000000..6f057e70f2
--- /dev/null
+++ b/packages/frontend-plugin-api/src/apis/definitions/ComponentsApi.ts
@@ -0,0 +1,37 @@
+/*
+ * 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 { ComponentRef } from '../../components';
+import { createApiRef } from '../system';
+
+/**
+ * API for looking up components based on component refs.
+ *
+ * @public
+ */
+export interface ComponentsApi {
+  // TODO: Should component refs also provide the default implementation so that we're guaranteed to get a component?
+  getComponent<T>(ref: ComponentRef<T>): T | undefined;
+}
+
+/**
+ * The `ApiRef` of {@link ComponentsApi}.
+ *
+ * @public
+ */
+export const componentsApiRef = createApiRef<ComponentsApi>({
+  id: 'core.components',
+});
diff --git a/packages/frontend-plugin-api/src/apis/definitions/index.ts b/packages/frontend-plugin-api/src/apis/definitions/index.ts
index 8791912e4a..f2496ee61a 100644
--- a/packages/frontend-plugin-api/src/apis/definitions/index.ts
+++ b/packages/frontend-plugin-api/src/apis/definitions/index.ts
@@ -34,6 +34,7 @@ export * from './auth';
 
 export * from './AlertApi';
 export * from './AppThemeApi';
+export * from './ComponentsApi';
 export * from './ConfigApi';
 export * from './DiscoveryApi';
 export * from './ErrorApi';