Fix problem with migration on empty database

acts_as_nested_interval.gemspec

@@ -7,9 +7,9 @@ require "acts_as_nested_interval/version"
 Gem::Specification.new do |s|
   s.name        = "acts_as_nested_interval"
   s.version     = ActsAsNestedInterval::VERSION
-  s.authors     = ["Nicolae Claudius", "Pythonic"]
-  s.email       = ["[email protected]"]
-  s.homepage    = "https://github.com/clyfe/acts_as_nested_interval"
+  s.authors     = ["Nicolae Claudius", "Pythonic", "Grzegorz Łuszczek"]
+  s.email       = ["[email protected]"]
+  s.homepage    = "https://github.com/grzlus/acts_as_nested_interval"
   s.summary     = "Encode Trees in RDBMS using nested interval method."
   s.description = "Encode Trees in RDBMS using nested interval method for powerful querying and speedy inserts."
 

lib/acts_as_nested_interval.rb

@@ -39,20 +39,22 @@ def acts_as_nested_interval(options = {})
       dependent: nested_interval_dependent
     scope :roots, -> { where(nested_interval_foreign_key => nil) }
 
-    if columns_hash["rgt"]
-      scope :preorder, -> { order('rgt DESC, lftp ASC') }
-    elsif columns_hash["rgtp"] && columns_hash["rgtq"]
-      scope :preorder, -> { order('1.0 * rgtp / rgtq DESC, lftp ASC') }
-    else
-      scope :preorder, -> { order('nested_interval_rgt(lftp, lftq) DESC, lftp ASC') }
-    end
+    if self.table_exists? # Fix problem with migrating without table
+      if columns_hash["rgt"]
+        scope :preorder, -> { order('rgt DESC, lftp ASC') }
+      elsif columns_hash["rgtp"] && columns_hash["rgtq"]
+        scope :preorder, -> { order('1.0 * rgtp / rgtq DESC, lftp ASC') }
+      else
+        scope :preorder, -> { order('nested_interval_rgt(lftp, lftq) DESC, lftp ASC') }
+      end
 
-    before_create :create_nested_interval
-    before_destroy :destroy_nested_interval
-    before_update :update_nested_interval
-
-    include ActsAsNestedInterval::InstanceMethods
-    extend ActsAsNestedInterval::ClassMethods
+      before_create :create_nested_interval
+      before_destroy :destroy_nested_interval
+      before_update :update_nested_interval
+
+      include ActsAsNestedInterval::InstanceMethods
+      extend ActsAsNestedInterval::ClassMethods
+    end
   end
 
 end

lib/acts_as_nested_interval/instance_methods.rb

@@ -111,7 +111,9 @@ def update_nested_interval
       end
     end
 
+    # Rewrite method
     def update_nested_interval_move
+      return if self.class.readonly_attributes.include?(nested_interval_foreign_key.to_sym) # Fix issue #9
       begin
         db_self = self.class.find(id)
         db_parent = self.class.find(read_attribute(nested_interval_foreign_key))
@@ -176,14 +178,22 @@ def ancestors
 
     # Returns depth by counting ancestors up to 0 / 1.
     def depth
-      n = 0
-      p, q = lftp, lftq
-      while p != 0
-        x = p.inverse(q)
-        p, q = (x * p - 1) / q, x
-        n += 1
+      if new_record?
+        if parent_id.nil?
+          return 0
+        else
+          return parent.depth + 1
+        end
+      else
+        n = 0
+        p, q = lftp, lftq
+        while p != 0
+          x = p.inverse(q)
+          p, q = (x * p - 1) / q, x
+          n += 1
+        end
+        return n
       end
-      n
     end
 
     def lft; 1.0 * lftp / lftq end

lib/acts_as_nested_interval/version.rb

@@ -1,3 +1,3 @@
 module ActsAsNestedInterval
-  VERSION = "0.1.0"
+  VERSION = "0.1.1"
 end