Active Admin share view helper

active_admin_share_views_helper.rb

# Example:
#
# ActiveAdmin.register Customer do
#   add_helper(:header) do |name|
#     h1(name)    
#   end
# 
#   index do
#     helper(:header, 'INDEX')
#    
#     # ...
#   end
#  
#   show do
#     helper(:header, 'SHOW')
#    
#     # ...
#   end
# end

class ActiveAdmin::DSL
  def add_helper(name, &block)
    config.add_helper(name, block)
  end
end

class ActiveAdmin::Views::Pages::Page
  def helper(name, *args)
    helper_proc = active_admin_config.helpers.fetch(name.to_s)

    instance_exec(*args, &helper_proc)
  end
end

class ActiveAdmin::Page
  def helpers
    @helpers ||= {}
  end

  def add_helper(name, block)
    helpers[name.to_s] = block
  end
end