万一有人无意中发现了这个问题，我有另一个解决方案，不依赖于dir读取或扩展Class类……

ActiveRecord::Base.send :subclasses

这将返回一个类数组。所以你可以这样做

ActiveRecord::Base.send(:subclasses).map(&:name)

编辑:看看评论和其他答案。有比这个更聪明的答案!或者尝试改进这个社区维基。

模型不会将自己注册到主对象，所以Rails没有模型列表。

但是您仍然可以在应用程序的models目录的内容中查找…

Dir.foreach("#{RAILS_ROOT}/app/models") do |model_path|
  # ...
end

编辑:另一个(疯狂的)想法是使用Ruby反射来搜索每个扩展ActiveRecord::Base的类。我不知道你怎么列出所有的类…

编辑:只是为了好玩，我找到了一种列出所有职业的方法

Module.constants.select { |c| (eval c).is_a? Class }

编辑:终于成功地列出所有型号，而不查看目录

Module.constants.select do |constant_name|
  constant = eval constant_name
  if not constant.nil? and constant.is_a? Class and constant.superclass == ActiveRecord::Base
    constant
  end
end

如果你也想处理派生类，那么你需要测试整个超类链。我通过在Class类中添加一个方法来做到这一点:

class Class
  def extend?(klass)
    not superclass.nil? and ( superclass == klass or superclass.extend? klass )
  end
end

def models 
  Module.constants.select do |constant_name|
    constant = eval constant_name
    if not constant.nil? and constant.is_a? Class and constant.extend? ActiveRecord::Base
    constant
    end
  end
end

在Rails 6中，Zetiwerk成为默认的代码加载器。

对于快速加载，请尝试:

Zeitwerk::Loader.eager_load_all

Then

ApplicationRecord.descendants

ActiveRecord:美国:基地connection。表

Rails实现了方法的后代，但模型不一定继承自ActiveRecord::Base，例如，包含ActiveModel::Model模块的类将具有与模型相同的行为，只是不会链接到表。

所以，与上面同事所说的相辅相成，最轻微的努力就会做到这一点:

Ruby的类别:

class Class
  def extends? constant
    ancestors.include?(constant) if constant != self
  end
end

方法模型，包括祖先，如下:

方法Module。constants返回(表面上)一个符号集合，而不是常量，因此，array# select方法可以像模块的猴子补丁一样被替换:

class Module

  def demodulize
    splitted_trail = self.to_s.split("::")
    constant = splitted_trail.last

    const_get(constant) if defines?(constant)
  end
  private :demodulize

  def defines? constant, verbose=false
    splitted_trail = constant.split("::")
    trail_name = splitted_trail.first

    begin
      trail = const_get(trail_name) if Object.send(:const_defined?, trail_name)
      splitted_trail.slice(1, splitted_trail.length - 1).each do |constant_name|
        trail = trail.send(:const_defined?, constant_name) ? trail.const_get(constant_name) : nil
      end
      true if trail
    rescue Exception => e
      $stderr.puts "Exception recovered when trying to check if the constant \"#{constant}\" is defined: #{e}" if verbose
    end unless constant.empty?
  end

  def has_constants?
    true if constants.any?
  end

  def nestings counted=[], &block
    trail = self.to_s
    collected = []
    recursivityQueue = []

    constants.each do |const_name|
      const_name = const_name.to_s
      const_for_try = "#{trail}::#{const_name}"
      constant = const_for_try.constantize

      begin
        constant_sym = constant.to_s.to_sym
        if constant && !counted.include?(constant_sym)
          counted << constant_sym
          if (constant.is_a?(Module) || constant.is_a?(Class))
            value = block_given? ? block.call(constant) : constant
            collected << value if value

            recursivityQueue.push({
              constant: constant,
              counted: counted,
              block: block
            }) if constant.has_constants?
          end
        end
      rescue Exception
      end

    end

    recursivityQueue.each do |data|
      collected.concat data[:constant].nestings(data[:counted], &data[:block])
    end

    collected
  end

end

猴子的绳子。

class String
  def constantize
    if Module.defines?(self)
      Module.const_get self
    else
      demodulized = self.split("::").last
      Module.const_get(demodulized) if Module.defines?(demodulized)
    end
  end
end

最后是模型方法

def models
  # preload only models
  application.config.eager_load_paths = model_eager_load_paths
  application.eager_load!

  models = Module.nestings do |const|
    const if const.is_a?(Class) && const != ActiveRecord::SchemaMigration && (const.extends?(ActiveRecord::Base) || const.include?(ActiveModel::Model))
  end
end

private

  def application
    ::Rails.application
  end

  def model_eager_load_paths
    eager_load_paths = application.config.eager_load_paths.collect do |eager_load_path|
      model_paths = application.config.paths["app/models"].collect do |model_path|
        eager_load_path if Regexp.new("(#{model_path})$").match(eager_load_path)
      end
    end.flatten.compact
  end

Rails5的模型现在是ApplicationRecord的子类，所以要获得应用程序中所有模型的列表，你需要:

ApplicationRecord.descendants.collect { |type| type.name }

或更短:

ApplicationRecord.descendants.collect(&:name)

如果你在开发模式下，你需要在以下情况之前加载模型:

Rails.application.eager_load!