rails json exclude nested attribute

Rails JSON exclude nested attribute

When working with Rails and generating JSON responses, you may come across situations where you want to exclude certain attributes from being included in the JSON output. This can be particularly useful when you have nested attributes that you don't want to include.

Using `as_json` method with `except` option

One way to exclude nested attributes is by using the `as_json` method with the `except` option. This will exclude the specified attributes from the JSON output.

def show
  @post = Post.find(params[:id])
  render json: @post.as_json(except: [:created_at, :updated_at, comments: [:created_at]])
end

In the above example, we are excluding the `created_at` and `updated_at` attributes from the main `Post` object, as well as the `created_at` attribute from any nested `Comment` objects.

Using `to_json` method with `only` option

Another way to exclude nested attributes is by using the `to_json` method with the `only` option. This will include only the specified attributes in the JSON output.

def show
  @post = Post.find(params[:id])
  render json: @post.to_json(only: [:title, :body], include: { author: { only: [:name] } })
end

In the above example, we are including only the `title` and `body` attributes from the main `Post` object, as well as the `name` attribute from the nested `Author` object.

Overall, there are different ways to exclude nested attributes in Rails JSON responses, and it all depends on the specific situation and requirements. The key is to use the appropriate method and options to achieve the desired output.