added command with interactive dialog

webapp/src/index.tsx

@@ -1,15 +1,31 @@
 import {Store, Action} from 'redux';
 
-import {GlobalState} from '@mattermost/types/lib/store';
+import {GlobalState} from 'mattermost-redux/types/store';
+import {getPost} from 'mattermost-redux/selectors/entities/posts';
 
 import manifest from '@/manifest';
 
 import {PluginRegistry} from '@/types/mattermost-webapp';
 
+import {triggerRemoveAttachmentsCommand} from './actions';
+
 export default class Plugin {
     // eslint-disable-next-line @typescript-eslint/no-unused-vars, @typescript-eslint/no-empty-function
     public async initialize(registry: PluginRegistry, store: Store<GlobalState, Action<Record<string, unknown>>>) {
         // @see https://developers.mattermost.com/extend/plugins/webapp/reference/
+        registry.registerPostDropdownMenuAction(
+            'Remove attachments',
+            async (postID) => {
+                store.dispatch(triggerRemoveAttachmentsCommand(postID) as any);
+            },
+            (postID) => {
+                const state = store.getState();
+                const post = getPost(state, postID);
+
+                // Don't show up if the post has no attachments. Permissions are checked server-side.
+                return typeof post.file_ids?.length !== 'undefined' && post.file_ids?.length > 0;
+            },
+        );
     }
 }