Rails active admin undefined methods - ruby-on-rails

Question

I'm using this code:
ActiveAdmin.register_page "Dashboard" do
section "Recent Posts" do
table_for Post.order("id desc").limit(15) do
column :id
column "Post title", :title do |post|
link_to post.title,[:admin,post]
end
column :category,sortable: :category
column :created_at
end
strong (link_to "Show all posts")
end
end
and I get this error:
undefined method `section'
if I delete 'section' do-end part, then I get error for:
undefined method `table_for'
and so on...
Seems like I cant use any of active admin given methods, maybe I'm mising something? Any gems or something? I installed active admin gem using this setup:
gem 'inherited_resources', github: 'activeadmin/inherited_resources'
gem 'activeadmin', github: 'activeadmin'
gem 'devise', github: 'plataformatec/devise'
I'm using rails 5

Answer 1

I managed to transform my code and now it compiles without any errors.
ActiveAdmin.register_page "Dashboard" do
content :title => proc{ I18n.t("active_admin.dashboard") } do
columns do
column do
panel "Recent Posts" do
table_for Post.order("id desc").limit(5) do
column :name do |post|
link_to post.title, [:admin, post]
end
column :created_at
end
strong (link_to "Show All Posts" , :posts )
end
end
end
end
end
I suppose my previously used syntax is old and not supported any more.