如何将redmine插件升级到rails 5，现在不推荐使用alias_method_chain

Question

故事模式

刚开始学习RoR，但是在短时间内我需要在我们的项目中添加类似于Loading images from LDAP（不兼容版本）的功能。项目被废除，我找不到任何相关的信息/文档，所以我在这里寻求帮助。解决方案，教程，任何事情都可行。

错误日志

$ ruby bin/rake redmine:plugins RAILS_ENV="production"
rake aborted!
NoMethodError: undefined method `alias_method_chain' for ApplicationHelper:Module
Did you mean?  alias_method
...

需要更新的Monkey补丁

plugins \ redmine_gemavatar \ lib \ application_helper_gemavatar_patch.rb：

require 'application_helper'

module GemAvatarPlugin
    module ApplicationAvatarPatch
        def self.included(base)
            base.send(:include, InstanceMethods)
            base.class_eval do
                alias_method_chain :avatar, :gemavatar
            end
        end
        module InstanceMethods
            def avatar_with_gemavatar(user, options = { })
                if Setting.gravatar_enabled? && user.is_a?(User)
                    options.merge!({:ssl => (defined?(request) && request.ssl?), :default => Setting.gravatar_default})
                    options[:size] = "64" unless options[:size]
                    avatar_url = url_for :controller => :pictures, :action => :delete, :user_id => user
                    return "<img class=\"gravatar\" width=\"#{options[:size]}\" height=\"#{options[:size]}\" src=\"#{avatar_url}\" />".html_safe
                else
                    ''
                end
            end
        end
    end
end

我的尝试/文章

我在这里找到了很好的文章How To Replace alias_method_chain，但我不太确定如何应用prepend样式来redmine插件的猴子补丁。只是不能让它工作：/

Answer 1

这与this plugin有关吗？

如果是这样，我会这样做：

• 在init.rb文件中，更改此：

RedmineApp::Application.config.after_initialize do
  ApplicationHelper.send(:include, GemAvatarPlugin::ApplicationAvatarPatch)
end

对此：

RedmineApp::Application.config.after_initialize do
  ApplicationHelper.prepend(GemAvatarPlugin::ApplicationAvatarPatch)
end

• 在lib/application_helper_gemavatar_patch.rb，改变这个：

require 'application_helper'

module GemAvatarPlugin
  module ApplicationAvatarPatch

    def self.included(base)
      base.send(:include, InstanceMethods)
      base.class_eval do
        alias_method_chain :avatar, :gemavatar
      end
    end

    module InstanceMethods

      def avatar_with_gemavatar(user, options = { })
        # method content omitted for clarity
      end

    end
  end
end

对此：

module GemAvatarPlugin
  module ApplicationAvatarPatch

    def avatar(user, options = { })
      # method content omitted for clarity
    end

  end
end

我会删除require 'application_helper'因为我不明白为什么需要它

Answer 2

您可以使用alias_method而不是alias_method_chain，但我正在寻找类似prepend解决方案的东西

                alias_method :avatar_without_gemavatar, :avatar
                alias_method :avatar, :avatar_with_gemavatar

UPD：但它会引发警告：

/app/helpers/application_helper.rb:180: warning: already initialized constant ApplicationHelper
::RECORD_LINK
/app/helpers/application_helper.rb:180: warning: previous definition of RECORD_LINK was here
/app/helpers/application_helper.rb:199: warning: already initialized constant ApplicationHelper
::ATTACHMENT_CONTAINER_LINK
/app/helpers/application_helper.rb:199: warning: previous definition of ATTACHMENT_CONTAINER_LI
NK was here
/app/helpers/application_helper.rb:1053: warning: already initialized constant ApplicationHelpe
r::LINKS_RE
/app/helpers/application_helper.rb:1053: warning: previous definition of LINKS_RE was here
Exiting

UPD：因为它已经包含在核心中，所以可以删除ste26054 mentioned in his answer and commented here require 'application_helper'以防止警告。