Element#data() should return nil for undefined attribute

adambeynon · adambeynon · commit 1814202085f1 · 2014-02-07T16:51:04.000Z
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,9 @@
 
 *   Add `LocalStorage` implementation.
 
+*   Fix Element#data() to return nil for an undefined data attribute instead
+    of null.
+
 ## 0.1.2 2013-12-01
 
 *   Support setting html content through `Element#html()`.
diff --git a/opal/opal-jquery/element.rb b/opal/opal-jquery/element.rb
@@ -59,7 +59,7 @@ def self.expose(*methods)
   # Bridged functions - we just expose all core jquery functions as ruby
   # methods on this class.
   expose :after, :before, :parent, :parents, :prepend, :prev, :remove
-  expose :hide, :show, :toggle, :children, :blur, :closest, :data
+  expose :hide, :show, :toggle, :children, :blur, :closest
   expose :focus, :find, :next, :siblings, :text, :trigger, :append
   expose :height, :width, :serialize, :is, :filter, :last, :first
   expose :wrap, :stop, :clone, :empty
@@ -182,6 +182,13 @@ def animate(params, &block)
     }
   end
 
+  def data(*args)
+    %x{
+      var result = self.data.apply(self, args);
+      return result == null ? nil : result;
+    }
+  end
+
   # Start a visual effect (e.g. fadeIn, fadeOut, …) passing its name.
   # Underscored style is automatically converted (e.g. `effect(:fade_in)`).
   # Also accepts additional arguments and a block for the finished callback.
diff --git a/spec/element_spec.rb b/spec/element_spec.rb
@@ -183,6 +183,28 @@
       foo.class_name.should == 'bar'
     end
   end
+
+end
+
+describe "Element#data" do
+  html <<-HTML
+    <div id="data-foo"></div>
+    <div id="data-ford" data-authur="dent"></div>
+  HTML
+
+  it "sets a data attribute" do
+    foo = Element.id('data-foo')
+    foo.data 'bar', 'baz'
+    expect(foo.data('bar')).to eq('baz')
+  end
+
+  it "can retrieve a data attribute" do
+    expect(Element.id('data-ford').data('authur')).to eq('dent')
+  end
+
+  it "returns nil for an undefined data attribute" do
+    expect(Element.id('data-ford').data('not-here')).to be_nil
+  end
 end
 
 describe "Element#html" do
