如题，我的是 Rails 5.2，并调用的时 @ichord 大神的 at.js。 现在，我能获取全部的当前用户，但是我不能通过后台获取用户的一些信息，并显示出来。

相关代码如下：

Rails 代码

## users_controller.rb
 def mentions
    respond_to do |format|
      format.json { render :json => Mention.all(params[:q]) }
    end
  end


## routes.rb

get 'mentions', to: 'users#mentions'


## mentions.rb 

class Mention
  attr_reader :mentionable
  include Rails.application.routes.url_helpers

  def self.all(letters)
    return Mention.none unless letters.present?
    users = User.limit(5).where('name LIKE ?', "#{letters}%").compact
    users.map do |user|
      { name: user.name, img: user.picture.nil? ? "images/default_member.png" : user.picture.url, name_before: user.name_before ? user.name_before : "" }
    end
  end

  def self.create_from_text(post)
    potential_matches = post.content.scan(/@\w+/i)
    potential_matches.uniq.map do |match|
      mention = Mention.create_from_match(match)
      next unless mention
      post.update_attributes(content: mention.markdown_string(post.content))
      # You could fire an email to the user here with ActionMailer
      mention
    end.compact
  end

  def self.create_from_match(match)
    user = User.find_by(name: match.delete('@'))
    UserMention.new(user) if user.present?
  end

  def initialize(mentionable)
    @mentionable = mentionable
  end

  class UserMention < Mention
    def markdown_string(text)
      host = Rails.env.development? ? 'localhost:3000' : '' # add your app's host here!
      text.gsub(/@#{mentionable.name}/i,
                "[**@#{mentionable.name}**]("")")
    end
  end
end


##  comments_controller.rb

def new
    @comment = Comment.new
    Mention.create_from_text(self)
  end

js 代码

## markdown.js


## 获取当前页面的全部用户，并去重。
function logins(){
        let uName = [];
        $("a.username").each(function () {
            uName.push($(this).text());
        });
        return $.unique(uName);
    }


### 调用atwho功能。
    function mentionable(logins){
        if(logins.length > 0){
            $("textarea").atwho({
                at: '@',
                limit: 8,
                callbacks:{
                    remoteFilter: function (query,callback) {
                        if(query.length < 1){
                            return false;
                        }else{
                            $.getJSON('/mentions',{q:query},function(data){
                                console.log(data)
                                callback(data);
                            });
                        }
                    }
                },
                'data':'/mentions',
                displayTpl: "<li data-value='@${name}'><img src='${img}' height='20' width='20' style='border-radius: 20px'/><span class='mlr5'>${name}</span> <small>${name_before}</small></li>",
            });
        }else{
            console.log("无内容");
        }
    }

    mentionable(logins());

请问下路过的各位大神，我按上述代码，当我在评论框，输入@时，提示错误信息如下，并且没有用户下拉框，但是在@后，输入字符，可以查询的到用户信息。

Completed 500 Internal Server Error in 9ms (ActiveRecord: 1.1ms)
NoMethodError - undefined method `none' for Mention:Class:
  app/models/mention.rb:6:in `all'
  app/controllers/users_controller.rb:73:in `block (2 levels) in mentions'
  app/controllers/users_controller.rb:72:in `mentions'