diff --git a/app/models/category.rb b/app/models/category.rb
index 874f560..edb1379 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -13,6 +13,16 @@ class Category < ActiveRecord::Base
     {:conditions => ['parent_id is null and environment_id = ?', environment.id ]}
   }
 
+  named_scope :on_level, lambda { |parent| {:conditions => {:parent_id => parent}} }
+
+  named_scope :sub_categories, lambda { |category|
+    {:conditions => ['categories.path LIKE ? AND categories.id != ?', "%#{category.slug}%", category.id]}
+  }
+
+  named_scope :sub_tree, lambda { |category|
+    {:conditions => ['categories.path LIKE ?', "%#{category.slug}%"]}
+  }
+
   acts_as_filesystem
 
   has_many :article_categorizations, :dependent => :destroy
diff --git a/app/models/product.rb b/app/models/product.rb
index 8d910e7..032c626 100644
--- a/app/models/product.rb
+++ b/app/models/product.rb
@@ -23,6 +23,10 @@ class Product < ActiveRecord::Base
 
   named_scope :more_recent, :order => "created_at DESC"
 
+  named_scope :from_category, lambda { |category|
+    {:joins => :product_category, :conditions => ['categories.path LIKE ?', "%#{category.slug}%"]} if category
+  }
+
   after_update :save_image
 
   def lat
diff --git a/test/unit/category_test.rb b/test/unit/category_test.rb
index 03b716a..f1c7a86 100644
--- a/test/unit/category_test.rb
+++ b/test/unit/category_test.rb
@@ -552,4 +552,62 @@ class CategoryTest < ActiveSupport::TestCase
     cat.save!
   end
 
+  should 'return categories of a level' do
+    c1 = fast_create(Category)
+    c2 = fast_create(Category)
+    c3 = fast_create(Category, :parent_id => c1)
+    c4 = fast_create(Category, :parent_id => c1)
+    c5 = fast_create(Category, :parent_id => c2)
+    c6 = fast_create(Category, :parent_id => c3)
+
+    assert_includes Category.on_level(nil), c1
+    assert_includes Category.on_level(nil), c2
+    assert_includes Category.on_level(c1), c3
+    assert_includes Category.on_level(c1), c4
+    assert_includes Category.on_level(c2), c5
+    assert_includes Category.on_level(c3), c6
+  end
+
+  should 'on level named_scope must be able to receive parent or parent_id' do
+    parent = fast_create(Category)
+    category = fast_create(Category, :parent_id => parent)
+
+    assert_includes Category.on_level(parent), category
+    assert_includes Category.on_level(parent.id), category
+  end
+
+  should 'list category sub-categories' do
+    c1 = Category.create!(:name => 'Category 1', :environment => Environment.default)
+    c2 = Category.create!(:name => 'Category 2', :environment => Environment.default)
+    c3 = Category.create!(:name => 'Category 3', :environment => Environment.default, :parent_id => c1)
+    c4 = Category.create!(:name => 'Category 4', :environment => Environment.default, :parent_id => c1)
+    c5 = Category.create!(:name => 'Category 5', :environment => Environment.default, :parent_id => c3)
+
+    sub_categories = Category.sub_categories(c1)
+
+    assert ActiveRecord::NamedScope::Scope, sub_categories.class
+    assert_not_includes sub_categories, c1
+    assert_not_includes sub_categories, c2
+    assert_includes sub_categories, c3
+    assert_includes sub_categories, c4
+    assert_includes sub_categories, c5
+  end
+
+  should 'list category sub-tree' do
+    c1 = Category.create!(:name => 'Category 1', :environment => Environment.default)
+    c2 = Category.create!(:name => 'Category 2', :environment => Environment.default)
+    c3 = Category.create!(:name => 'Category 3', :environment => Environment.default, :parent_id => c1)
+    c4 = Category.create!(:name => 'Category 4', :environment => Environment.default, :parent_id => c1)
+    c5 = Category.create!(:name => 'Category 5', :environment => Environment.default, :parent_id => c3)
+
+    sub_tree = Category.sub_tree(c1)
+
+    assert ActiveRecord::NamedScope::Scope, sub_tree.class
+    assert_includes sub_tree, c1
+    assert_not_includes sub_tree, c2
+    assert_includes sub_tree, c3
+    assert_includes sub_tree, c4
+    assert_includes sub_tree, c5
+  end
+
 end
diff --git a/test/unit/product_test.rb b/test/unit/product_test.rb
index 3d22f0f..a45590a 100644
--- a/test/unit/product_test.rb
+++ b/test/unit/product_test.rb
@@ -772,4 +772,40 @@ class ProductTest < ActiveSupport::TestCase
     assert_equal [prod3, prod2, prod1], Product.more_recent
   end
 
+  should 'return products from a category' do
+    pc1 = ProductCategory.create!(:name => 'PC1', :environment => Environment.default)
+    pc2 = ProductCategory.create!(:name => 'PC2', :environment => Environment.default)
+    pc3 = ProductCategory.create!(:name => 'PC3', :environment => Environment.default, :parent => pc1)
+    p1 = fast_create(Product, :product_category_id => pc1)
+    p2 = fast_create(Product, :product_category_id => pc1)
+    p3 = fast_create(Product, :product_category_id => pc2)
+    p4 = fast_create(Product, :product_category_id => pc3)
+
+    products = Product.from_category(pc1)
+
+    assert_includes products, p1
+    assert_includes products, p2
+    assert_not_includes products, p3
+    assert_includes products, p4
+  end
+
+  should 'not crash if nil is passed to from_category' do
+    assert_nothing_raised do
+      Product.from_category(nil)
+    end
+  end
+
+  should 'return from_category scope untouched if passed nil' do
+    enterprise = fast_create(Enterprise)
+    p1 = fast_create(Product, :enterprise_id => enterprise.id)
+    p2 = fast_create(Product, :enterprise_id => enterprise.id)
+    p3 = fast_create(Product, :enterprise_id => enterprise.id)
+
+    products = enterprise.products.from_category(nil)
+
+    assert_includes products, p1
+    assert_includes products, p2
+    assert_includes products, p3
+  end
+
 end
--
libgit2 0.21.2