refactor(element_binder): Remove bindAttrName

Author: jbdeboer

lib/core_dom/common.dart

@@ -6,15 +6,12 @@ List<dom.Node> cloneElements(elements) {
 
 class MappingParts {
   final String attrName;
-  final String bindAttrName;
   final AST attrValueAST;
   final String mode;
   final AST dstAST;
   final String originalValue;
 
-  MappingParts(attrName, this.attrValueAST, this.mode, this.dstAST, this.originalValue)
-    : attrName = attrName,
-      bindAttrName = "bind-" + attrName;
+  MappingParts(this.attrName, this.attrValueAST, this.mode, this.dstAST, this.originalValue);
 }
 
 class DirectiveRef {

lib/core_dom/element_binder.dart

@@ -119,7 +119,7 @@ class ElementBinder {
       }
 
       // Check if there is a bind attribute for this mapping.
-      var bindAttr = bindAttrs[p.bindAttrName];
+      var bindAttr = bindAttrs[p.attrName];
       if (bindAttr != null) {
         if (p.mode == '<=>') {
           if (directiveScope == null) {

lib/core_dom/selector.dart

@@ -21,6 +21,9 @@ part of angular.core.dom_internal;
  *  * [*=/abc/]
  */
 class DirectiveSelector {
+  static String BIND_PREFIX = "bind-";
+  static int BIND_PREFIX_LENGTH = 5;
+
   ElementBinderFactory _binderFactory;
   DirectiveMap _directives;
   Interpolate _interpolate;
@@ -86,8 +89,9 @@ class DirectiveSelector {
 
       if (attrName.startsWith("on-")) {
         builder.onEvents[attrName] = value;
-      } else if (attrName.startsWith("bind-")) {
-        builder.bindAttrs[attrName] = _astParser(value, formatters: _formatters);
+      } else if (attrName.startsWith(BIND_PREFIX)) {
+        builder.bindAttrs[attrName.substring(BIND_PREFIX_LENGTH)] =
+            _astParser(value, formatters: _formatters);
       }
 
       attrs[attrName] = value;

test/core_dom/selector_spec.dart

@@ -215,8 +215,8 @@ main() {
       it('should collect bind-* attributes', () {
         ElementBinder binder = selector(e('<input bind-x="y" bind-z="yy"></input>'));
         expect(binder.bindAttrs.keys.length).toEqual(2);
-        expect(binder.bindAttrs['bind-x'].expression).toEqual('y');
-        expect(binder.bindAttrs['bind-z'].expression).toEqual('yy');
+        expect(binder.bindAttrs['x'].expression).toEqual('y');
+        expect(binder.bindAttrs['z'].expression).toEqual('yy');
       });
     });