如何在Rails中存储全局共享的数据结构?

I have a data structure like this in one of my models:

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

I use this in a custom validator I have to validate the sizes of images uploaded. I would like to be able to use this data structure not just in this one model - but everywhere. In all my models, views and controllers.

我在自定义验证器中使用它，我必须验证上传图片的大小。我希望能够不仅在这个模型中，而且在任何地方使用这个数据结构。在我所有的模型、视图和控制器中。

How would I go about doing that, where would I put it?

我该怎么做，把它放在哪里?

2 个解决方案

#1

I would use a module.

我会用一个模块。

Stick it in your lib directory. (You may need to configure Rails 3 to autoload classes and modules from your lib folder. See this question.)

把它放在你的库目录中。(您可能需要从lib文件夹中配置Rails 3到autoload类和模块。见这个问题。)

# 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

Then in your models or controllers:

然后在你的模型或控制器中:

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


class MyController < ApplicationController
  include ImageSizes
  # ...
end

Now, each model or controller that includes the ImageSizes module will have access to the module's methods, namely image_size_limits.

现在，包括ImageSizes模块的每个模型或控制器都可以访问模块的方法，即image_size_limit。

#2

Another option is to create an initializer file and declare a constant there.

另一个选项是创建初始化文件并在其中声明一个常量。

# config/initializers/image_size_limits.rb

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}
}

Then in your model or controller, just use IMAGE_SIZE_LIMITS['web']['maxheight'] to get 480.

然后在您的模型或控制器中，只需使用image_size_limit ['web']['maxheight']为480。

#1