[RUBY] Use multiple checkboxes in Rails6!

I used multiple checkboxes while implementing the user registration function of the original app! I will post it for the first time as a memorandum for beginners! If you make a mistake, please point it out in the comments lol

How to write a check box There are many ways to write a check box. This time I used the check_box method because there is a related model.

 <%= f.check_box  :food, {multiple: true}, food, nil %>

It is like this. In the food part, enter the object name you want to specify. By the way, the column type is specified by text type. Write {multiple: true} to allow multiple selections.

Allow key parameters Since devise is used for user registration in this application production, we will describe it in application_controller.rb to allow the parameter of the check box in the private method.

  def configure_permitted_parameters
    devise_parameter_sanitizer.permit(:sign_up, keys: [:nickname, food:[]])
  end

Don't forget [].

How to write the form screen

It is like this.

<div class="field">
    <% %w(Steak hamburger sushi omelet rice).each.with_index do |food,i| %>
    <label>
      <%= f.check_box  :food, {multiple: true}, food, nil %>
      <%= food %>
    </label>
    <% end %>
  </div>

Checkbox items are placed in the array using% notation. Then, using each.with_index, the elements of the array are stored in the variable food and numbered. Don't forget to associate form items with the lebel tag

that's all! !! form is difficult lol Since I'm a beginner, I didn't know how to write it, and there were some things I couldn't understand, but I think it would be useful to be able to use it! If you make a mistake or have a better way to write it, please let me know! I tried to imitate it by referring to other sites, but I think the implementation was successful! The site I referred to is here! ⇓⇓ https://www.sejuku.net/blog/27132