Helper
2016-01-05 本文已影响19人
臻有一扑
Helper
What
ActionController::Helpers
Basically helpers in Rails are used to extract complex logic out of the view so that you can organize your code better.
Advantages
-
Extract some complexity out of the view
-
Make view logic easier to test
Move complexity out of the view
把一些复杂的逻辑从view层中抽出来，放在controller里面：
<% if @user && @user.email.present? %>
<%= @user.email %>
<% end %>
完全可以在controller里面这样：
#site_helper.rb
module SiteHelper
def user_email(user)
user.email if user && user.email.present?
end
end
#user_controller.rb
class UserController
helper SiteHelper
end
有一个method很近似，那就是helper_method
下面来看他们两的区别
helper vs helper_method
helper_method可以把controller中的method share给view
helper则是把整个Hepler 引入到view中，相当于：
``
include_all_helpers
``
