Add a clearMessages() method in ChatModel (#195)

Author: brichet

packages/jupyter-chat/src/model.ts

@@ -101,6 +101,11 @@ export interface IChatModel extends IDisposable {
    */
   sendMessage(message: INewMessage): Promise<boolean | void> | boolean | void;
 
+  /**
+   * Clear the message list.
+   */
+  clearMessages(): void;
+
   /**
    * Optional, to update a message from the chat panel.
    *
@@ -403,6 +408,14 @@ export class ChatModel implements IChatModel {
    */
   sendMessage(message: INewMessage): Promise<boolean | void> | boolean | void {}
 
+  /**
+   * Clear the message list.
+   */
+  clearMessages(): void {
+    this._messages = [];
+    this._messagesUpdated.emit();
+  }
+
   /**
    * Dispose the chat model.
    */

packages/jupyterlab-chat/src/model.ts

@@ -173,6 +173,13 @@ export class LabChatModel extends ChatModel implements DocumentRegistry.IModel {
     this.sharedModel.addMessage(msg);
   }
 
+  /**
+   * Override the clear messages method.
+   */
+  clearMessages(): void {
+    // No-op as we may not need to clear the messages in file based chat.
+  }
+
   updateMessage(
     id: string,
     updatedMessage: IChatMessage