Include specs to ensure that columns aren't included when unavailable.

lib/table_cloth/presenter.rb

@@ -28,8 +28,14 @@ def render_rows
 
     def columns
       @columns ||= table.class.columns.map do |name, options|
-        options[:class].new(name, options[:options])
-      end
+        column = options[:class].new(name, options[:options])
+
+        if ColumnJury.new(column, table).available?
+          column
+        else
+          nil
+        end
+      end.compact
     end
 
     def column_names

spec/factories/dummy_tables.rb

@@ -0,0 +1,11 @@
+FactoryGirl.define do
+  factory :dummy_table, class: "TableCloth::Base" do
+    initialize_with do
+      Class.new(TableCloth::Base).tap do |klass|
+        attributes.each do |key,attribute|
+          klass.column *[key, attribute]
+        end
+      end
+    end
+  end
+end

spec/lib/presenter_spec.rb

@@ -20,14 +20,31 @@
         expect(column).to be_kind_of TableCloth::Column
       end
     end
+
+    context "that are unavaialble" do
+      let(:dummy_table) { FactoryGirl.build(:dummy_table, email: {if: :admin?}) }
+      let(:table_instance) { dummy_table.new(objects, view_context) }
+      before(:each) do 
+        table_instance.stub admin?: false
+        subject.stub table: table_instance
+      end
+
+      specify "are not returned" do
+        expect(subject).to have(0).columns
+      end
+
+      specify "name is not returned" do
+        expect(subject.column_names).not_to include "email"
+      end
+    end
   end
 
   context ".column_names" do
     let(:table_instance) { dummy_table.new(objects, view_context) }
     before(:each) { table_instance.stub admin?: false, awesome?: true }
 
     it 'returns all names' do
-      subject.column_names.should =~ ["Id", "Name", "Email"]
+      subject.column_names.should == ["Id", "Name", "Email"]
     end
   end