Add a smaller version of dom.js to renderer

src/renderer/scr.dom.js

@@ -0,0 +1,40 @@
+var DOM = (function(){
+  return {
+    /*
+     * Returns a child element by its ID. Parent defaults to the entire document.
+     */
+    id: function(id, parent){
+      return (parent || document).getElementById(id);
+    },
+    
+    /*
+     * Returns an array of all child elements containing the specified class. Parent defaults to the entire document.
+     */
+    cls: function(cls, parent){
+      return Array.prototype.slice.call((parent || document).getElementsByClassName(cls));
+    },
+    
+    /*
+     * Returns an array of all child elements that have the specified tag. Parent defaults to the entire document.
+     */
+    tag: function(tag, parent){
+      return Array.prototype.slice.call((parent || document).getElementsByTagName(tag));
+    },
+    
+    /*
+     * Creates an element, adds it to the DOM, and returns it.
+     */
+    createElement: function(tag, parent){
+      var ele = document.createElement(tag);
+      parent.appendChild(ele);
+      return ele;
+    },
+    
+    /*
+     * Removes an element from the DOM.
+     */
+    removeElement: function(ele){
+      ele.parentNode.removeChild(ele);
+    }
+  };
+})();