ruby-on-rails - 在 Rails 中存储全局共享数据结构的位置

Question

我的一个模型中有这样的数据结构:

def image_size_limits
    {
        "web" => {"maxheight" => 480, "maxwidth" => 680, "minheight" => 400, "minwidth" => 600}, 
        "phone" => {"height" => 345, "width" => 230, "minheight" => 300, "minwidth" => 200},
        "tablet" => {"height" => 680, "width" => 480, "minheight" => 600, "minwidth" => 400},
        "other" => {"height" => 680, "width" => 480, "minheight" => 600, "minwidth" => 400}
    }
end

我在自定义验证器中使用它，我必须验证上传图像的大小。我希望不仅可以在这个模型中使用这个数据结构，而且可以在任何地方使用。在我所有的模型、 View 和 Controller 中。

我该怎么做，我应该把它放在哪里？

Answer 1

我会使用模块。

将其粘贴到您的 lib 目录中。 (您可能需要配置 Rails 3 以从您的 lib 文件夹自动加载类和模块。参见 this question。)

# lib/image_sizes.rb

module ImageSizes
  def image_size_limits
    {
      "web" => {"maxheight" => 480, "maxwidth" => 680, "minheight" => 400, "minwidth" => 600}, 
      "phone" => {"height" => 345, "width" => 230, "minheight" => 300, "minwidth" => 200},
      "tablet" => {"height" => 680, "width" => 480, "minheight" => 600, "minwidth" => 400},
      "other" => {"height" => 680, "width" => 480, "minheight" => 600, "minwidth" => 400}
    }
  end
end

然后在您的模型或 Controller 中:

class MyModel < ActiveRecord::Base
  include ImageSizes
  # ...
end


class MyController < ApplicationController
  include ImageSizes
  # ...
end

现在，每个包含 ImageSizes 模块的模型或 Controller 都可以访问该模块的方法，即 image_size_limits。