Initial commit of Effen reactive framework experiment for Sky

sky/examples/fn/lib/style.dart

+part of fn;
+
+class Style {
+  final String _className;
+  static Map<String, Style> _cache = null;
+
+  static int nextStyleId = 1;
+
+  static String nextClassName(String styles) {
+    assert(sky.document != null);
+    var className = "style$nextStyleId";
+    nextStyleId++;
+
+    var styleNode = sky.document.createElement('style');
+    styleNode.setChild(new sky.Text(".$className { $styles }"));
+    sky.document.appendChild(styleNode);
+
+    return className;
+  }
+
+  factory Style(String styles) {
+    if (_cache == null) {
+      _cache = new HashMap<String, Style>();
+    }
+
+    var style = _cache[styles];
+    if (style == null) {
+      style = new Style._internal(nextClassName(styles));
+      _cache[styles] = style;
+    }
+
+    return style;
+  }
+
+  Style._internal(this._className);
+}