Enable :if condition for node properties

lib/rabl-fast-json/compiler.rb

@@ -47,8 +47,18 @@ module RablFastJson
     end
 
     def node(name, options = {}, &block)
+      condition = options[:if]
+
+      if condition.present?
+        if condition.is_a?(Proc)
+          @template[name] = [condition, block]
+        else
+          @template[name] = block if condition
+        end
+      else
         @template[name] = block
       end
+    end
     alias_method :code, :node
 
     def collection(data, options = {})

lib/rabl-fast-json/template.rb

@@ -30,6 +30,9 @@ module RablFastJson
           data.send(value) # attributes
         when Proc
           value.call(data) # node
+        when Array # node with condition
+          next output if !value.first.call(data)
+          value.last.call(data)
         when Hash
           current_value = value.dup
           data_symbol = current_value.delete(:_data)

test/compiled_template_test.rb

@@ -36,4 +36,24 @@ class TestCompiledTemplate < ActiveSupport::TestCase
       { :uid => 2, :name => 'bar', :gender => 'female'}
     ], @template.render)
   end
+
+  test "render object with node property" do
+    proc = lambda { |object| object.sex }
+    @template.source = { :sex => proc }
+    assert_equal({ :sex => 'male' }, @template.render)
+  end
+
+  test "render obejct with conditionnal node property" do
+    condition = lambda { |u| u.name.present? }
+    proc = lambda { |object| object.name }
+    @template.source = { :name => [condition, proc] }
+    assert_equal({ :name => 'foobar' }, @template.render)
+  end
+
+  test "render node property with false condition" do
+    condition = lambda { |u| false }
+    proc = lambda { |object| object.name }
+    @template.source = { :name => [condition, proc] }
+    assert_equal({}, @template.render)
+  end
 end

test/compiler_test.rb

@@ -122,4 +122,11 @@ class CompilerTest < ActiveSupport::TestCase
     assert_not_nil t.source[:foo]
     assert_instance_of Proc, t.source[:foo]
   end
+
+  test "node with condition are compiled as an array of procs" do
+    t = @compiler.compile_source(%{ node(:foo, :if => lambda { |m| m.foo.present? }) do |m| m.foo end })
+    assert_not_nil t.source[:foo]
+    assert_instance_of Array, t.source[:foo]
+    assert_equal 2, t.source[:foo].size
+  end
 end