Ruby on rails 从类中呈现分部时，Url帮助程序不可用

我有一个helper类，它呈现一个片段以将内容存储在数据库中

它可以正常工作，但是当视图包含url帮助器提供的url时

<%= link_to "Show project", projects_url, class: "button" %>

我在类通知中包含此帮助程序

class Notification < ActiveRecord::Base
  include NotificationRender

  .....
  def self.create_for(user, event, params)   
      template = "notifications/_email_project"
      list_params = {:template => template,:locals => params}
      notification = Notification.new
      notification.message = notification.render(list_params) #here I render the partial
      notification.subject = I18n.t "subject.#{event}"
      notification.to = user.email     
      notification.save
 end

end

---

您可能必须在渲染帮助器中包含URL帮助器

class Notification < ActiveRecord::Base
  include NotificationRender

  .....
  def self.create_for(user, event, params)   
      template = "notifications/_email_project"
      list_params = {:template => template,:locals => params}
      notification = Notification.new
      notification.message = notification.render(list_params) #here I render the partial
      notification.subject = I18n.t "subject.#{event}"
      notification.to = user.email     
      notification.save
 end

end