ruby-on-rails – Rails :: Railtie：无法创建Rails 3 gem

我真的可以用另一套眼睛,所以我想我会把它贴在这里.
不久之前,我为自己的教育目的写了一个基本的ActiveRecord扩展.我最近一直在阅读有关Railties的文章,并且我认为我会尝试使用Rails 3.我想我会把它打包成一块宝石来了解这个过程.
如果我跳过Railtie并在初始化文件夹中将其作为传统的monkeypatch执行,它可以正常工作.使用铁路……没什么.

从它的外观来看,我的Railtie永远不会被执行,因此似乎没有其他任何事情发生.

这里有人看错吗？

我们也欢迎任何有关最佳实践或改进的建议.

项目Gemfile：

gem 'sql_explain',:path => "/home/mike/projects/sql_explain/"

gemspec：

...
  spec.files = %w(README.rdoc sql_explain.rb lib/sql_explain.rb lib/railtie.rb sql_explain.gemspec)
...

sql_explain.rb

require 'lib/railtie.rb'

railtie.rb

require 'active_record'
require 'sql_explain'

module SqlExplain
  class Railtie < Rails::Railtie
    railtie_name :sql_explain
    initializer 'sql_explain.extend.activerecord' do
      if defined?(ActiveRecord)
        ActiveRecord::ConnectionAdapters::MysqlAdapter.include SqlExplain::AR
      end
    end
  end
end

sql_explain.rb

module SqlExplain
  module AR
    def self.included(base_klass)
      base_klass.send :alias_method_chain,:select,:explain
    end


    def select_with_explain(sql,name = nil)
      @connection.query_with_result = true
      result = execute('explain ' + sql,:skip_logging)
      rows = []
      result.each_hash { |row| rows << row }
      result.free
      @connection.more_results && @connection.next_result    # invoking stored procedures with CLIENT_MULTI_RESULTS requires this to tidy up else connection will be dropped
      exp_string = ""
      rows.each{|row| row.each_pair{|k,v| exp_string += " #{k}: #{v} |"}}
      log(exp_string,"Explanation") {}
      select_without_explain(sql,name)
    end
  end
end

ActiveSupport.on_load :active_record do
  ActiveRecord::ConnectionAdapters::MysqlAdapter.include SqlExplain::AR
end