Rails 创建了一个可通过模型和控制器访问的方法

Question

无论如何创建一个我可以在模型和控制器中调用的函数？我有一个函数可以抓取一组文件并剥离扩展名并希望针对列表进行验证。但是我也想在控制器中访问这个列表，这样我就可以输出一个选项的选择框。我目前有这个，但是 VALID_MODULES 并没有一直被填充。

class Job < ActiveRecord::Base

  after_initialize :init
  VALID_MODULES =[];

  validates :name, presence: true
  validates :desc, presence: true
  validates :api, presence: true, :inclusion => { :in => VALID_MODULES}
  validates :filters, presence: true
  validates :toe, presence: true

  def init
    Dir.foreach('lib/resources') do |item|
         next if item == '.' or item == '..' or item == 'resource.rb'
            #Wont be called very often so O(n) complexity is fine (small #elements)
            VALID_MODULES.push(item[0..-4]) unless VALID_MODULES.include?(item[0..-4])
    end
  end

end

Answer 1

不要使用常量 (VALID_MODULES)，而是尝试将其作为 job 的属性。

class Job < ActiveRecord::Base

  attr_accessor :valid_modules
  after_initialize :init


  validates :name, presence: true
  validates :desc, presence: true
  validates :api, presence: true, :inclusion => { :in => VALID_MODULES}
  validates :filters, presence: true
  validates :toe, presence: true

  def init
    @valid_modules ||= []
    Dir.foreach('lib/resources') do |item|
         next if ['.', '..', 'resource.rb'].include?(item)
         #Wont be called very often so O(n) complexity is fine (small #elements)
         @valid_modules << item[0..-4] unless @valid_modules.include?(item[0..-4])
    end
  end

end

现在在您的控制器中，您只需在您的 Job 对象上调用 valid_modules 即可返回数组。 示例：

job = Job.new
job.valid_modules

Answer 2

# in config/initializers/api_modules.rb
module ApiModules
  def self.modules
    # the Dir[""] glob syntax here I believe exclude dot directories
    # but I still like the Array#include? syntax here for your exclusions list
    # you may need to massage the strings of your file list to be more appropriate to your case
    @modules ||= Dir["lib/*"].select{|f| !["resource.rb"].include?(f) } 
  end
end

#app/models/job.rb
validates :api, presence: true, :inclusion => { :in => ApiModules.modules}