diff --git a/lib/rabl-rails.rb b/lib/rabl-rails.rb
index 2b67406..db3c321 100644
--- a/lib/rabl-rails.rb
+++ b/lib/rabl-rails.rb
@@ -5,6 +5,7 @@ require 'active_support/core_ext/class/attribute_accessors'
 
 require 'rabl-rails/version'
 require 'rabl-rails/template'
+require 'rabl-rails/condition'
 require 'rabl-rails/compiler'
 
 require 'rabl-rails/renderer'
diff --git a/lib/rabl-rails/compiler.rb b/lib/rabl-rails/compiler.rb
index 357e2c2..707a279 100644
--- a/lib/rabl-rails/compiler.rb
+++ b/lib/rabl-rails/compiler.rb
@@ -5,7 +5,7 @@ module RablRails
   #
   class Compiler
     def initialize
-      @glue_count = 0
+      @i = 0
     end
 
     #
@@ -80,8 +80,8 @@ module RablRails
     #
     def glue(data)
       return unless block_given?
-      name = :"_glue#{@glue_count}"
-      @glue_count += 1
+      name = :"_glue#{@i}"
+      @i += 1
       @template[name] = sub_compile(data) { yield }
     end
 
@@ -118,6 +118,20 @@ module RablRails
       @template.merge!(t.source)
     end
 
+    #
+    # Provide a conditionnal block
+    #
+    # condition(->(u) { u.is_a?(Admin) }) do
+    #   attributes :secret
+    # end
+    #
+    def condition(proc)
+      return unless block_given?
+      name = :"_if#{@i}"
+      @i += 1
+      @template[name] = Condition.new(proc, sub_compile(nil) { yield })
+    end
+
     protected
 
     #
@@ -142,7 +156,7 @@ module RablRails
       return {} unless block_given?
       old_template, @template = @template, {}
       yield
-      @template.merge!(:_data => data)
+      data ? @template.merge!(:_data => data) : @template
     ensure
       @template = old_template
     end
diff --git a/lib/rabl-rails/condition.rb b/lib/rabl-rails/condition.rb
new file mode 100644
index 0000000..68cc5b3
--- /dev/null
+++ b/lib/rabl-rails/condition.rb
@@ -0,0 +1,10 @@
+module RablRails
+  class Condition
+    attr_reader :proc, :source
+
+    def initialize(proc, source)
+      @proc = proc
+      @source = source
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/rabl-rails/renderers/base.rb b/lib/rabl-rails/renderers/base.rb
index c336de3..ef664d7 100644
--- a/lib/rabl-rails/renderers/base.rb
+++ b/lib/rabl-rails/renderers/base.rb
@@ -78,6 +78,11 @@ module RablRails
             else # child
               object.respond_to?(:each) ? render_collection(object, current_value) : render_resource(object, current_value)
             end
+          when Condition
+            if instance_exec data, &(value.proc)
+              output.merge!(render_resource(data, value.source))
+            end
+            next output
           end
           output[key] = out
           output
diff --git a/test/compiler_test.rb b/test/compiler_test.rb
index d2d8c8f..7011939 100644
--- a/test/compiler_test.rb
+++ b/test/compiler_test.rb
@@ -153,6 +153,12 @@ class CompilerTest < ActiveSupport::TestCase
     assert_equal 2, t.source[:foo].size
   end
 
+  test "conditionnal block compile nicely" do
+    t = @compiler.compile_source(%{ condition(->(u) {}) do attributes :secret end })
+    assert_instance_of RablRails::Condition, t.source[:_if0]
+    assert_equal({ :secret => :secret }, t.source[:_if0].source)
+  end
+
   test "compile with no object" do
     t = @compiler.compile_source(%{
      object false
diff --git a/test/renderers/json_renderer_test.rb b/test/renderers/json_renderer_test.rb
index 93d3ab0..ec0cd80 100644
--- a/test/renderers/json_renderer_test.rb
+++ b/test/renderers/json_renderer_test.rb
@@ -127,6 +127,18 @@ class TestJsonRenderer < ActiveSupport::TestCase
     assert_equal %q({"users":[]}), render_json_output
   end
 
+  test "condition blocks are transparent if the condition passed" do
+    c = RablRails::Condition.new(->(u) { true }, { :name => :name })
+    @template.source = { :_if0 => c }
+    assert_equal %q({"name":"foobar"}), render_json_output
+  end
+
+  test "condition blocks are ignored if the condition is not met" do
+    c = RablRails::Condition.new(->(u) { false }, { :name => :name })
+    @template.source = { :_if0 => c }
+    assert_equal %q({}), render_json_output
+  end
+
   test "render object with root node" do
     @template.root_name = :author
     @template.source = { :id => :id, :name => :name }