Rails表单,以一种形式创建多个父母和子女

class Parent< ApplicationRecord
  has_many :children
  accepts_nested_attributes_for :children, allow_destroy: true
end

def new
  @parent = Parent.new
  3.times { @parent.children.build }
end

def edit
  @parent = Parent.find(params[:id])
  3.times { @parent.children.build }
end

<%= form_with(model: parent) do |f| %>
  <%= f.label :name %>
  <%= f.text_field :name %>

  <%= f.fields_for :children do |child_form| %>
    <%= child_form.label :name, "Child Name" %>
    <%= child_form.text_field :name %>
  <% end %>

  <%= f.submit "Submit" %>
<% end %>

def create
  @parent = Parent.new(parent_params)

  if @parent.save
    redirect_to @parent
  else
    render :new
  end
end

def update
  @parent = Parent.find(params[:id])

  if @parent.update(parent_params)
    redirect_to @parent
  else
    render :edit
  end
end

private

def parent_params
  params.require(:parent).permit(:name, children_attributes: [:id, :name, :_destroy])
end