如何使用邮箱程序从用户的显示页面创建对话？

Question

我正在遵循某个教程来使用邮箱程序创建用户-用户消息传递系统。

问题是，我希望一个用户能够在另一用户的页面（收件人）上创建对话，而不必从收件人列表中选择对话。
到目前为止，这是我已经完成的工作，我在用户的显示页面上添加了一个表单部分用于对话，但是我试图删除必须选择收件人的那一部分，而我希望由params[:id]设置收件人

有什么想法或建议吗？也许有办法将下面的选择的默认值设置为params[:id]吗？

<%= form_for :conversation, url: :conversations, html: { class: "" } do |f| %>
  <div class="form-group">
    <%= f.label :recipients %>
    <p id="recipient-select"><%= f.select(:recipients, @users.all.collect {|p| [ p.username, p.id ] }, {}, { multiple: true}) %></p>       
  </div> 
  <div class="form-group">
    <%= f.label :subject %>
    <%= f.text_field :subject, placeholder: "Subject", class: "form-control", :required => true %>
  </div>
  <div class="form-group">
    <%= f.label :message %>
    <%= f.text_area :body, class: 'form-control',placeholder: "Type your message here", rows: 4  %>
  </div>
  <%= f.submit "Send Message", class: "btn btn-success" %>
<% end %>

会话控制器

class ConversationsController < ApplicationController
  before_action :authenticate_user!

  def create
    recipients = User.where(id: conversation_params[:recipients])
    recipients.each do |recipient|
      if recipient != current_user
        @recipient = recipient
      end
    end
    conversation = current_user.send_message(recipients, conversation_params[:body], conversation_params[:subject]).conversation
    flash[:success] = "Your message was successfully sent!"
    redirect_to conversation_path(conversation)
  end

  def show
    @receipts = conversation.receipts_for(current_user)
    conversation.mark_as_read(current_user)
  end

  def reply
    current_user.reply_to_conversation(conversation, message_params[:body])
    flash[:notice] = "Your reply message was successfully sent!"
    redirect_to conversation_path(conversation)
  end

  private

  def message_params
    params.require(:message).permit(:body, :subject)
  end

  def conversation_params
    params.require(:conversation).permit(:subject, :body,recipients:[])
  end

end