refactor(core): remove direct accesses to DOM

Closes #713

modules/angular2/src/facade/dom.dart

@@ -11,6 +11,7 @@ export 'dart:html' show
   Node,
   StyleElement,
   TemplateElement,
+  InputElement,
   Text,
   window;
 
@@ -57,6 +58,10 @@ class DOM {
   static void setInnerHTML(Element el, String value) {
     el.innerHtml = value;
   }
+  static String nodeName(Node el) => el.nodeName;
+  static String nodeValue(Node el) => el.nodeValue;
+  static String type(InputElement el) => el.type;
+  static Node content(TemplateElement el) => el.content;
   static Node firstChild(el) => el.firstChild;
   static Node nextSibling(Node el) => el.nextNode;
   static Element parentElement(Node el) => el.parent;
@@ -87,6 +92,14 @@ class DOM {
   static void setText(Node el, String value) {
     el.text = value;
   }
+  static String getValue(InputElement el) => el.value;
+  static void setValue(InputElement el, String value) {
+    el.value = value;
+  }
+  static bool getChecked(InputElement el) => el.checked;
+  static void setChecked(InputElement el, bool isChecked) {
+    el.checked = isChecked;
+  }
   static TemplateElement createTemplate(String html) {
     var t = new TemplateElement();
     t.setInnerHtml(html, treeSanitizer: identitySanitizer);
@@ -163,4 +176,10 @@ class DOM {
   static HtmlDocument defaultDoc() => document;
   static bool elementMatches(n, String selector) =>
       n is Element && n.matches(selector);
+  static bool isTemplateElement(Element el) =>
+      el is TemplateElement;
+  static bool isTextNode(Node node) =>
+      node.nodeType == Node.TEXT_NODE;
+  static bool isElementNode(Node node) =>
+      node.nodeType == Node.ELEMENT_NODE;
 }

modules/angular2/src/facade/dom.es6

@@ -42,6 +42,18 @@ export class DOM {
   static getOuterHTML(el) {
     return el.outerHTML;
   }
+  static nodeName(node:Node):string {
+    return node.nodeName;
+  }
+  static nodeValue(node:Node):string {
+    return node.nodeValue;
+  }
+  static type(node:Element):string {
+    return node.type;
+  }
+  static content(node:TemplateElement):Node {
+    return node.content;
+  }
   static firstChild(el):Node {
     return el.firstChild;
   }
@@ -97,6 +109,18 @@ export class DOM {
   static setText(el, value:string) {
     el.textContent = value;
   }
+  static getValue(el: Element) {
+    return el.value;
+  }
+  static setValue(el: Element, value:string) {
+    el.value = value;
+  }
+  static getChecked(el: Element) {
+    return el.checked;
+  }
+  static setChecked(el: Element, value:boolean) {
+    el.checked = value;
+  }
   static createTemplate(html) {
     var t = document.createElement('template');
     t.innerHTML = html;
@@ -181,4 +205,13 @@ export class DOM {
   static elementMatches(n, selector:string):boolean {
     return n instanceof Element && n.matches(selector);
   }
+  static isTemplateElement(el:any):boolean {
+    return el instanceof TemplateElement;
+  }
+  static isTextNode(node:Node):boolean {
+    return node.nodeType === Node.TEXT_NODE;
+  }
+  static isElementNode(node:Node):boolean {
+    return node.nodeType === Node.ELEMENT_NODE;
+  }
 }