# Deleting A Book Listing By ID - Planning

Refer back to [*Chapter 6, The Bookstore API Endpoint Specifications, API Endpoint #9: Delete a Book Listing*](https://book.restfulnode.com/chapter-6/1-the-bookstore-api-endpoint-specifications#api-endpoint-9-delete-a-book-listing) section for the API endpoint specifications.

## 1 - Route Name

Finally, our final API endpoint. For the delete a book by ID, it will be very similar to updating.

We'll just use `DELETE` instead of `PUT` as our method verb of choice.

`DELETE /api/v1/books/:id`

## 2 - Input Request

None.

## 3 - Middleware

This will be the exact same as the last section.

For the first layer, we'll be reusing our `isAuthenticated` helper that will protect us from unauthenticated user from accessing this endpoint.

For the second layer, we'll be reusing our `bookPermission` helper to verify that the requested book ID exists and that the currently authenticated user is in fact the owner of it.

## 4 - Validation

None.

## 5 - Domain

Just like the last section, we'll built on top of the previous section and use the **bookModel**.

We'll also need some sort of way to make a query to the database in order to find the existing book and delete it, so we'll use the `bookRepository` layer and add the method `deleteById()` to do so.

**bookRepository**

* `deleteById()`

On top of that, our controller will call a service to `deleteBookById()`, in this case, it will be the `bookService` which will use the `bookRepository` layer.

**bookService**

* `deleteBookById()`

## 6 - Events

None.

## 7 - Response

Again, very similar to the previous section, except there will be 3 possible responses that can be output with this endpoint.

The first is the authentication middleware that we'll be reusing.

```json
{
  "status": "error",
  "code": 401,
  "message": "Access denied: you must be logged in to access this API endpoint.",
  "data": null,
  "errors": ["You must be logged in."]
}
```

The second is whether or not the client has inputted an existing book ID.

```json
{
    "status": "error",
    "code": 404,
    "message": "That book with the specified ID does not exist."
    "data": null,
    "errors": [
        "Book listing not found."
    ]
}
```

The third is the successful scenario. Do keep in mind that since we are using a `DELETE` request, so won't be returning any representation back.

```json
{
  "status": "success",
  "code": 200,
  "message": "The book has successfully been deleted.",
  "data": {},
  "errors": null
}
```