Proper NaFieldStyler sub-field hiding support

* src/ui/styler/NaFieldStyler.js (_isSubField): Added
(applyStyle, revokeStyle): Will not hide parents of sub-fields

src/ui/styler/NaFieldStyler.js

@@ -59,6 +59,14 @@ module.exports = Class( 'NaFieldStyler' )
         // removed once jQuery is eradicated from the framework
         element.style = '';
 
+        if ( this.isSubField( element ) )
+        {
+            // this is a child of another field; don't consider it a
+            // containing row, since we don't want our operations affecting
+            // it
+            return;
+        }
+
         for ( var i in row )
         {
             this.addClass( row[ i ], 'hidden' );
@@ -79,6 +87,34 @@ module.exports = Class( 'NaFieldStyler' )
     'public revokeStyle': function( field, element, row )
     {
         this.removeClass( element, 'hidden' );
+
+        if ( this.isSubField( element ) )
+        {
+            return;
+        }
+
         this.removeClass( row, 'hidden' );
+    },
+
+
+    /**
+     * Determine whether element ELEMENT represents a sub-field
+     *
+     * A sub-field is a field within a field; the distinction is important
+     * because we probably don't want operations on a sub-field affecting
+     * its parent.
+     *
+     * @todo: move somewhere else (Field perhaps?)
+     *
+     * @param {HTMLElement} element DOM element associated with field
+     *
+     * @return {boolean} whether ELEMENT represents a sub-field
+     */
+    'protected isSubField': function( element )
+    {
+        var parent = element.parentElement;
+
+        // ES3-compatible (don't use classList)
+        return !!( parent && /\bwidget\b/.test( parent.className ) );
     }
 } );

test/ui/styler/NaFieldStylerTest.js

@@ -68,6 +68,50 @@ describe( 'ui.styler.NaFieldStyler', function()
                 expect( ele.style ).to.equal( '' );
             } );
         } );
+
+
+        it( 'does not set class on subfield parents', function()
+        {
+            var element = {
+                className: '',
+                parentElement: { className: 'widget' }
+            };
+
+            var r1      = { className: '' },
+                r2      = { className: '' },
+                row     = [ r1, r2 ];
+
+            Sut().applyStyle( {}, element, row );
+
+            expect( element.className ).to.match( /\bhidden\b/ );
+
+            [ r1, r2 ].forEach( function( ele )
+            {
+                expect( ele.className ).to.equal( '' );
+            } );
+        } );
+
+
+        it( 'does not clears style subfield parents', function()
+        {
+            var element = {
+                style: 'foo',
+                parentElement: { className: 'widget' }
+            };
+
+            var r1      = { style: 'foo' },
+                r2      = { style: 'foo' },
+                row     = [ r1, r2 ];
+
+            Sut().applyStyle( {}, element, row );
+
+            expect( element.style ).to.equal( '' );
+
+            [ r1, r2 ].forEach( function( ele )
+            {
+                expect( ele.style ).to.equal( 'foo' );
+            } );
+        } );
     } );
 
 
@@ -104,5 +148,68 @@ describe( 'ui.styler.NaFieldStyler', function()
                 expect( ele.style ).to.equal( 'foo' );
             } );
         } );
+
+
+        it( 'does not remove hidden class on subfield parents', function()
+        {
+            var element = {
+                className: 'foo hidden',
+                parentElement: { className: 'widget' }
+            };
+
+            var r1      = { className: 'foo hidden' },
+                r2      = { className: 'foo hidden' },
+                row     = [ r1, r2 ];
+
+            Sut().revokeStyle( {}, element, row );
+
+            expect( element.className ).to.not.match( /\bhidden\b/ );
+            expect( element.className ).to.match( /foo/ );
+
+            [ r1, r2 ].forEach( function( ele )
+            {
+                expect( ele.className ).to.equal( 'foo hidden' );
+            } );
+        } );
+    } );
+
+
+    describe( 'protected API', function()
+    {
+        describe( '#isSubField', function()
+        {
+            it( 'recognizes parent widget class as subfield', function()
+            {
+                var element = {
+                    className: '',
+                    parentElement: { className: 'widget' }
+                };
+
+                expect( protSut().protIsSubField( element ) )
+                    .to.be.true;
+            } );
+
+
+            it( 'missing parent widget class is non-subfield', function()
+            {
+                var element = {
+                    className: '',
+                };
+
+                expect( protSut().protIsSubField( element ) )
+                    .to.be.false;
+            } );
+        } );
     } );
 } );
+
+
+function protSut()
+{
+    return Class.extend( Sut, {
+        protIsSubField: function( element )
+        {
+            return this.isSubField( element );
+        }
+    } )();
+}