Ruby-on-rails Rails 3：获取当前命名空间？
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Rails 3: Get current namespace?
提问by arnekolja
using a method :layout_for_namespace I set my app's layout depending on whether I am in frontend or backend, as the backend is using an namespace "admin".
使用方法 :layout_for_namespace 我根据我是在前端还是后端来设置应用程序的布局，因为后端使用命名空间“admin”。
I could not find a pretty way to find out which namespace I am, the only way I found is by parsing the string from params[:controller]. Of course that's easy, seems to be fail-safe and working good. But I am just wondering if there's a better, prepared, way to do this. Does anyone know?
我找不到一种很好的方法来找出我是哪个命名空间，我找到的唯一方法是解析来自 params[:controller] 的字符串。当然，这很容易，似乎是故障安全的并且运行良好。但我只是想知道是否有更好的、准备好的方法来做到这一点。有人知道吗？
Currently I am just using the following method:
目前我只是使用以下方法：
def is_backend_namespace?
params[:controller].index("admin/") == 0
end
Thanks in advance
提前致谢
Arne
阿恩
回答by William Wong Garay
You can use:
您可以使用：
self.class.parent == Admin
回答by Ryan Crispin Heneise
Outside the controller (e.g. in the views), use controller.class.name. You can turn this into a helper method like this:
在控制器之外（例如在视图中），使用 controller.class.name。你可以把它变成这样的辅助方法：
module ApplicationHelper
def admin?
controller.class.name.split("::").first=="Admin"
end
end
回答by KenB
In both the controller and the views, you can parse controller_path, eg.:
在控制器和视图中，您都可以解析 controller_path，例如：
namespace = controller_path.split('/').first
回答by johnmcaliley
Not much more elegant, but it uses the class instead of the params hash. I am not aware of a "prepared" way to do this without some parsing.
没有更优雅，但它使用类而不是 params 哈希。我不知道没有一些解析的“准备”方式来做到这一点。
self.class.to_s.split("::").first=="Admin"
回答by Jason Harrelson
None of these solutions consider a constant with multiple parent modules. For instance:
这些解决方案都没有考虑具有多个父模块的常量。例如：
A::B::C
As of Rails 3.2.x you can simply:
从 Rails 3.2.x 开始，您可以简单地：
"A::B::C".deconstantize #=> "A::B"
As of Rails 3.1.x you can:
从 Rails 3.1.x 开始，您可以：
constant_name = "A::B::C"
constant_name.gsub( "::#{constant_name.demodulize}", '' )
This is because #demodulize is the opposite of #deconstantize:
这是因为#demodulize 与#deconstantize 相反：
"A::B::C".demodulize #=> "C"
If you really need to do this manually, try this:
如果您确实需要手动执行此操作，请尝试以下操作：
constant_name = "A::B::C"
constant_name.split( '::' )[0,constant_name.split( '::' ).length-1]
回答by Danny
Setting the namespace in application controller:
在应用程序控制器中设置命名空间：
path = self.controller_path.split('/')
@namespace = path.second ? path.first : nil
回答by Sami Birnbaum
Rails 6
导轨 6
Accessing the namespace in the view?
访问视图中的命名空间？
do not use: controller.namespace.parent == Admin
不使用： controller.namespace.parent == Admin
the parentmethod will be removed in Rails 6.1
该parent方法将在 Rails 6.1 中删除
DEPRECATION WARNING: `Module#parent` has been renamed to `module_parent`. `parent` is deprecated and will be removed in Rails 6.1.
use module_parentinstead:
使用module_parent来代替：
controller.namespace.module_parent == Admin
controller.namespace.module_parent == Admin
回答by staxim
In Rails 6, the controller class does not seem to have a namespacemethod on it.
在Rails 6 中，控制器类似乎没有namespace方法。
The solution that seemed cleanest and worked for me in a view was: controller.class.module_parent
看起来最干净并且对我有用的解决方案是： controller.class.module_parent
Specifically, if your namespace is Admin:: and you wanted 'admin', you'd do:
controller.class.module_parent.to_s.downcase
具体来说，如果你的命名空间是 Admin:: 并且你想要“admin”，你会这样做：
controller.class.module_parent.to_s.downcase
