Ruby on rails 组消息收发邮箱

我将遵循以下教程（向下滚动到相关部分的底部）：

我的消息\u helper.rb：

def recipients_options(chosen_recipient = nil)
  s = ''
  User.all.each do |user|
     s << "<option value='#{user.id}' data-img-src='#{gravatar_image_url(user.email, size: 50)}' #{'selected' if user == chosen_recipient}>#{user.name}</option>"
  end
  s.html_safe
end

---

现在，这允许通过如下url传递一个当前收件人：。但是我希望能够为“组消息”传入多个当前用户，因此类似于：

的url确保正在呈现的选择具有名称：name='to[]'

这不起作用。如果您选择了多个收件人，它已经可以发送多个收件人，但我希望它们已经被选中，因为它们是在参数中发送的

<div class="form-group">
  <%= label_tag 'recipients', 'Choose recipients' %>
  <%= select_tag 'recipients', recipients_options(@chosen_recipient), multiple: true, class: 'form-control chosen-it' %>
</div>

def new
  @chosen_recipient = User.find_by(id: params[:to].to_i) if params[:to]
end
def create
   recipients = User.where(id: params['recipients'])
   conversation = current_user.send_message(recipients, params[:message][:body], params[:message][:subject]).conversation
   flash[:success] = "Message has been sent!"
   redirect_to conversation_path(conversation)
end