Added WhenNotEmpty component.

web-view-components/src/main/groovy/groowt/view/component/web/DefaultWebViewComponentScope.groovy

@@ -1,10 +1,7 @@
 package groowt.view.component.web
 
 import groowt.view.component.context.DefaultComponentScope
-import groowt.view.component.web.lib.Each
+import groowt.view.component.web.lib.*
-import groowt.view.component.web.lib.Echo
-import groowt.view.component.web.lib.IntrinsicHtml
-import groowt.view.component.web.lib.WhenNotNull
 import org.codehaus.groovy.runtime.InvokerHelper
 
 import static WebViewComponentFactories.withAttr
@@ -15,6 +12,7 @@ class DefaultWebViewComponentScope extends DefaultComponentScope implements WebV
         new DefaultWebViewComponentScope().tap {
             addWithAttr(Echo)
             addWithAttr(Each)
+            addWithAttr(WhenNotEmpty)
             addWithAttr(WhenNotNull)
         }
     }

web-view-components/src/main/groovy/groowt/view/component/web/lib/WhenNotEmpty.groovy

@@ -0,0 +1,24 @@
+package groowt.view.component.web.lib
+
+import groowt.view.View
+import groowt.view.component.runtime.DefaultComponentWriter
+
+class WhenNotEmpty extends DelegatingWebViewComponent {
+
+    private final Collection items
+
+    WhenNotEmpty(Map attr) {
+        items = attr.items
+    }
+
+    @Override
+    protected View getDelegate() {
+        return { Writer w ->
+            if (!items.empty) {
+                def cw = new DefaultComponentWriter(w, context.renderContext, context)
+                children.each { cw << it }
+            }
+        }
+    }
+
+}