Fixed decoding entities in attribute values

This was broken by introducing the process of lazy decoding of XML/HTML
entities. The new setup works similar to how XML::Text#text decodes any
entities that may be present.

Fixes #91

lib/oga/xml/attribute.rb

@@ -10,16 +10,12 @@ module Oga
     # @!attribute [rw] namespace_name
     #  @return [String]
     #
-    # @!attribute [rw] value
-    #  The value of the attribute.
-    #  @return [String]
-    #
     # @!attribute [r] element
     #  The element this attribute belongs to.
     #  @return [Oga::XML::Element]
     #
     class Attribute
-      attr_accessor :name, :namespace_name, :element, :value
+      attr_accessor :name, :namespace_name, :element
 
       ##
       # The default namespace available to all attributes. This namespace can
@@ -67,8 +63,28 @@ module Oga
       end
 
       ##
-      # Returns the value of the attribute.
+      # @param [String] value
       #
+      def value=(value)
+        @value   = value
+        @decoded = false
+      end
+
+      ##
+      # Returns the value of the attribute or nil if no explicit value was set.
+      #
+      # @return [String|NilClass]
+      #
+      def value
+        if !@decoded and @value
+          @value   = EntityDecoder.try_decode(@value, html?)
+          @decoded = true
+        end
+
+        return @value
+      end
+
+      ##
       # @return [String]
       #
       def text
@@ -108,6 +124,15 @@ module Oga
 
         return "Attribute(#{segments.join(' ')})"
       end
+
+      private
+
+      ##
+      # @return [TrueClass|FalseClass]
+      #
+      def html?
+        return !!@element && @element.html?
+      end
     end # Attribute
   end # XML
 end # Oga

spec/oga/xml/attribute_spec.rb

@@ -37,6 +37,66 @@ describe Oga::XML::Attribute do
     end
   end
 
+  describe '#value=' do
+    it 'sets the value of an attribute' do
+      attr = described_class.new
+
+      attr.value = 'foo'
+
+      attr.value.should == 'foo'
+    end
+
+    it 'flushes the decoded cache when setting a new value' do
+      attr = described_class.new(:value => '<')
+
+      attr.value.should == Oga::XML::Entities::DECODE_MAPPING['<']
+
+      attr.value = '>'
+
+      attr.value.should == Oga::XML::Entities::DECODE_MAPPING['>']
+    end
+  end
+
+  describe '#value' do
+    it 'returns the value of an attribute' do
+      described_class.new(:value => 'foo').value.should == 'foo'
+    end
+
+    describe 'using an XML document' do
+      before do
+        @el  = Oga::XML::Element.new(:name => 'a')
+        @doc = Oga::XML::Document.new(:children => [@el], :type => :xml)
+      end
+
+      it 'returns a String with decoded XML entities' do
+        attr = described_class.new(
+          :name    => 'class',
+          :value   => '<',
+          :element => @el
+        )
+
+        attr.value.should == '<'
+      end
+    end
+
+    describe 'using HTML documents' do
+      before do
+        @el  = Oga::XML::Element.new(:name => 'a')
+        @doc = Oga::XML::Document.new(:children => [@el], :type => :html)
+      end
+
+      it 'returns a String with decoded HTML entities' do
+        attr = described_class.new(
+          :name    => 'class',
+          :value   => '&copy;',
+          :element => @el
+        )
+
+        attr.value.should == Oga::HTML::Entities::DECODE_MAPPING['&copy;']
+      end
+    end
+  end
+
   describe '#text' do
     it 'returns an empty String when there is no value' do
       described_class.new.text.should == ''