Fix https://github.com/ClosureTree/closure_tree/issues/308

README.md

@@ -423,7 +423,7 @@ and in your model:
 
 ```ruby
 class OrderedTag < ActiveRecord::Base
-  has_closure_tree order: 'sort_order'
+  has_closure_tree order: 'sort_order', numeric_order: true
 end
 ```
 

lib/closure_tree/has_closure_tree.rb

@@ -8,6 +8,7 @@ def has_closure_tree(options = {})
         :hierarchy_table_name,
         :name_column,
         :order,
+        :numeric_order,
         :touch,
         :with_advisory_lock
       )

lib/closure_tree/support.rb

@@ -22,7 +22,8 @@ def initialize(model_class, options)
         :parent_column_name => 'parent_id',
         :dependent => :nullify, # or :destroy or :delete_all -- see the README
         :name_column => 'name',
-        :with_advisory_lock => true
+        :with_advisory_lock => true,
+        :numeric_order => false
       }.merge(options)
       raise ArgumentError, "name_column can't be 'path'" if options[:name_column] == 'path'
       if order_is_numeric?

lib/closure_tree/support_flags.rb

@@ -17,13 +17,7 @@ def order_option?
     end
 
     def order_is_numeric?
-      # skip if database is not connected.
-      return false unless ::ActiveRecord::Base.connected?
-
-      # The table might not exist yet (in the case of ActiveRecord::Observer use, see issue 32)
-      return false if !order_option? || !model_class.table_exists?
-      c = model_class.columns_hash[order_column]
-      c && c.type == :integer
+      options[:numeric_order]
     end
 
     def subclass?

spec/db/models.rb

@@ -81,6 +81,7 @@ class ContractType < ActiveRecord::Base
 class Label < ActiveRecord::Base
   # make sure order doesn't matter
   acts_as_tree :order => :column_whereby_ordering_is_inferred, # <- symbol, and not "sort_order"
+    :numeric_order => true,
     :parent_column_name => "mother_id",
     :dependent => :destroy