Ruby / Rails - 如何创建类并从控制器访问它 [英] Ruby/Rails - How to Create a Class and Access it from the Controller

问题描述

我一直在尝试使用一些不同的gems在rails 3中显示googlemaps，并有几个问题。

幸运的是，我发现这https://github.com/YouthTree/bhm-google-maps 这是一个帮手，它似乎为其他人工作。

我已正确安装，但在readme https://github.com/YouthTree/bhm-google-maps/blob/master/README.md 它提到为要在视图中显示的对象创建一个类。

他们给的例子是

  class Location 
 attr_accessor：address，：lat ，：lng 
 def initialize（address，lat，lng）
 @address = address 
 @lat = lat 
 @lng = lng 
 end 
 def to_s; address.to_s; end 
 end 
  

然后运行

 <％= draw_map_of Location.new（My House，12.345，56.789）％> 
 
 
 
 
 
 
很简单，但我没有经历需要在rails中创建一个类，所以我有一些问题。
 
 
 
应该创建一个location.rb文件，并放置上面代码，但是我应该在哪里放置文件？ （模型文件夹，应用程序文件夹????）
 
 
 
我可以在我的控制器中创建这个类吗？
 
 
 
理想情况下，我想将lat / lng值作为变量操作并显示动态地图。
解决方案
应该把 location.rb 放在你觉得最合理的地方。让它在 app / models / location.rb 将确保它是在应用程序启动时自动需要的，但有些人希望在 app / models 由ActiveRecord支持。
 
 
 
您也可以将它放在 lib /  
 
 
 
要使其可用于应用程序，可以在config文件夹中的项目初始化程序中包含require语句：
  require＃{RAILS.root} /lib/location.rb 
  
至于在你的控制器中创建它肯定是一个类的另一个实例：
  def show 
 @location = Location.new（My House，12.345，56.789）
 end 
  
然后在您的视图中：
 <％= draw_map_of @location％> 
  
不要忘记 - 下面的Rails是纯Ruby的所有力量和灵活性，准备好使用你不仅限于Rails给了你什么。
 
I've been trying to use a few different gems for displaying googlemaps within rails 3 and have had several problems.

Luckily I found this https://github.com/YouthTree/bhm-google-maps which is a helper and it seems to work for others.

I've installed it properly but in the readme https://github.com/YouthTree/bhm-google-maps/blob/master/README.md  it mentions creating a class for the object to display in the view.

The example they gave was 
class Location
   attr_accessor :address, :lat, :lng
   def initialize(address, lat, lng)
      @address = address
      @lat = lat
      @lng = lng
   end
  def to_s; address.to_s; end
end
And then running 
 <%= draw_map_of Location.new("My House", 12.345, 56.789) %>
in the view.

It seems simple enough but I haven't experienced the need of creating a class before in rails  so I have some questions.

Should I create a location.rb file and place the above code in it, but where should I place the file? (model folder, application folder????)

Is there a way for me to create this class within my controller?

Ideally I would like to manipulate the lat/lng values as variables and display a dynamic map.
解决方案
You should put location.rb wherever you feel it makes the most sense. Having it at app/models/location.rb will ensure that it's automatically required when your app starts, but some people expect that classes in app/models are backed by ActiveRecord.

You could also put it under lib/ if you prefer.

To make it available to the app, you can include require statement in project initializers inside your config folder:
require "#{RAILS.root}/lib/location.rb
As for creating it inside your Controller - definitely! It's just another instance of a class:
def show
  @location = Location.new("My House", 12.345, 56.789)
end
And then in your view:
<%= draw_map_of @location %>
Don't forget – beneath Rails is all the power and flexibility of pure Ruby, ready to be used. You're not only limited to what Rails gives you.

                        
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