Hoot Back-End Delete Comment

Learning objective: By the end of this lesson, students will be able build a route that deletes embedded sub-documents inside a single hoot.

Overview

In this section, we will create a delete route to find and delete a single comment within a hoot.

We will be following these specs when building the route:

• CRUD Action: DELETE
• Method: DELETE
• Path: /hoots/<hoot_id>/comments/<comment_id>
• Response: JSON
• Success Status Code: 200 Ok
• Success Response Body: A JSON status message.
• Error Status Code: 500 Internal Server Error
• Error Response Body: A JSON object with an error key and a message describing the error

Define the route

Next we’ll define a route that listens for DELETE requests on /hoots/<hoot_id>/comments/<comment_id>:

DELETE /hoots/<hoot_id>/comments/<comment_id>

We’ll make use of our @token_required decorator, as only a logged in user should be able to delete a comment.

Add the following to comments_blueprint.py:

@comments_blueprint.route('/hoots/<hoot_id>/comments/<comment_id>', methods=['DELETE'])
@token_required

🏆 Any route that requires auth should include the @token_required decorator. These are our protected routes.

Code the controller function

Let’s breakdown what we’ll accomplish inside our controller function.

Our function will use the connection cursor to execute the following SQL queries:

SELECT * FROM comments WHERE id = %s

DELETE FROM comments WHERE id = %s

This should resemble our previous update and delete routes, since we’ll need to check for ownership before allowing a user to delete a comment.

Add the following to comments_blueprint.py:

@comments_blueprint.route('/hoots/<hoot_id>/comments/<comment_id>', methods=['DELETE'])
@token_required
def delete_comment(hoot_id, comment_id):
    try:
        connection = get_db_connection()
        cursor = connection.cursor(cursor_factory=psycopg2.extras.RealDictCursor)
        cursor.execute("SELECT * FROM comments WHERE id = %s", (comment_id,))
        comment_to_delete = cursor.fetchone()
        if comment_to_delete is None:
            return jsonify({"error": "Comment not found"}), 404
        if comment_to_delete["author"] != g.user["id"]:
            return jsonify({"error": "Unauthorized"}), 401
        cursor.execute("DELETE FROM comments WHERE id = %s", (comment_id,))
        connection.commit()
        connection.close()
        return jsonify({"message": "Comment deleted successfully"}), 200
    except Exception as error:
        return jsonify({"error": str(error)}), 500

Test the route in Postman

Now that we have the route, let’s test it with Postman.

We’ll do this by sending a DELETE request to the following URL:

http://127.0.0.1:5000/hoots/4/comments/1

💡 Be sure to update this with hoot and comment id values that exists in your database!

If the request is successful, you should see a response like the one below:

{
  "message": "Comment deleted successfully"
}