feat(ngModel): support ngTrim attribute on input

src/ng/directive/input.js

@@ -25,19 +25,21 @@ var inputType = {
    *    patterns defined as scope expressions.
    * @param {string=} ngChange Angular expression to be executed when input changes due to user
    *    interaction with the input element.
+   * @param {boolean=} [ngTrim=true] If set to false Angular will not automatically trimming the
+   *    input.
    *
    * @example
       <doc:example>
         <doc:source>
          <script>
            function Ctrl($scope) {
              $scope.text = 'guest';
-             $scope.word = /^\w*$/;
+             $scope.word = /^\s*\w*\s*$/;
            }
          </script>
          <form name="myForm" ng-controller="Ctrl">
            Single word: <input type="text" name="input" ng-model="text"
-                               ng-pattern="word" required>
+                               ng-pattern="word" required ng-trim="false">
            <span class="error" ng-show="myForm.input.$error.required">
              Required!</span>
            <span class="error" ng-show="myForm.input.$error.pattern">
@@ -66,6 +68,12 @@ var inputType = {
             input('text').enter('hello world');
             expect(binding('myForm.input.$valid')).toEqual('false');
           });
+
+          it('should not be trimmed', function() {
+            input('text').enter('untrimmed ');
+            expect(binding('text')).toEqual('untrimmed ');
+            expect(binding('myForm.input.$valid')).toEqual('true');
+          });
         </doc:scenario>
       </doc:example>
    */
@@ -370,7 +378,14 @@ function isEmpty(value) {
 function textInputType(scope, element, attr, ctrl, $sniffer, $browser) {
 
   var listener = function() {
-    var value = trim(element.val());
+    var value = element.val();
+
+    // By default we will trim the value
+    // If the attribute ng-trim exists we will avoid trimming
+    // e.g. <input ng-model="foo" ng-trim="false">
+    if (toBoolean(attr.ngTrim || 'T')) {
+      value = trim(value);
+    }
 
     if (ctrl.$viewValue !== value) {
       scope.$apply(function() {

test/ng/directive/inputSpec.js

@@ -382,6 +382,14 @@ describe('input', function() {
   });
 
 
+  it('should update the model and not trim the value', function() {
+    compileInput('<input type="text" ng-model="name" name="alias" ng-trim="false" />');
+
+    changeInputValueTo('  a  ');
+    expect(scope.name).toEqual('  a  ');
+  });
+
+
   it('should allow complex reference binding', function() {
     compileInput('<input type="text" ng-model="obj[\'abc\'].name"/>');