docs(input[checkbox]): mention ngChecked

Closes angular#14465
Closes angular#15277

Author: vgvenkat

src/ng/directive/input.js

@@ -1027,6 +1027,148 @@ var inputType = {
    */
   'radio': radioInputType,
 
+  /**
+   * @ngdoc input
+   * @name input[range]
+   *
+   * @description
+   * Native range input with validation and transformation.
+   *
+   * <div class="alert alert-warning">
+   *   <p>
+   *     In v1.5.9+, in order to avoid interfering with already existing, custom directives for
+   *     `input[range]`, you need to let Angular know that you want to enable its built-in support.
+   *     You can do this by adding the `ng-input-range` attribute to the input element. E.g.:
+   *     `<input type="range" ng-input-range ... />`
+   *   </p><br />
+   *   <p>
+   *     Input elements without the `ng-input-range` attibute will continue to be treated the same
+   *     as in previous versions (e.g. their model value will be a string not a number and Angular
+   *     will not take `min`/`max`/`step` attributes and properties into account).
+   *   </p><br />
+   *   <p>
+   *     **Note:** From v1.6.x onwards, the support for `input[range]` will be always enabled and
+   *     the `ng-input-range` attribute will have no effect.
+   *   </p><br />
+   *   <p>
+   *     This documentation page refers to elements which have the built-in support enabled; i.e.
+   *     elements _with_ the `ng-input-range` attribute.
+   *   </p>
+   * </div>
+   *
+   * The model for the range input must always be a `Number`.
+   *
+   * IE9 and other browsers that do not support the `range` type fall back
+   * to a text input without any default values for `min`, `max` and `step`. Model binding,
+   * validation and number parsing are nevertheless supported.
+   *
+   * Browsers that support range (latest Chrome, Safari, Firefox, Edge) treat `input[range]`
+   * in a way that never allows the input to hold an invalid value. That means:
+   * - any non-numerical value is set to `(max + min) / 2`.
+   * - any numerical value that is less than the current min val, or greater than the current max val
+   * is set to the min / max val respectively.
+   * - additionally, the current `step` is respected, so the nearest value that satisfies a step
+   * is used.
+   *
+   * See the [HTML Spec on input[type=range]](https://www.w3.org/TR/html5/forms.html#range-state-(type=range))
+   * for more info.
+   *
+   * This has the following consequences for Angular:
+   *
+   * Since the element value should always reflect the current model value, a range input
+   * will set the bound ngModel expression to the value that the browser has set for the
+   * input element. For example, in the following input `<input type="range" ng-input-range ng-model="model.value">`,
+   * if the application sets `model.value = null`, the browser will set the input to `'50'`.
+   * Angular will then set the model to `50`, to prevent input and model value being out of sync.
+   *
+   * That means the model for range will immediately be set to `50` after `ngModel` has been
+   * initialized. It also means a range input can never have the required error.
+   *
+   * This does not only affect changes to the model value, but also to the values of the `min`,
+   * `max`, and `step` attributes. When these change in a way that will cause the browser to modify
+   * the input value, Angular will also update the model value.
+   *
+   * Automatic value adjustment also means that a range input element can never have the `required`,
+   * `min`, or `max` errors.
+   *
+   * However, `step` is currently only fully implemented by Firefox. Other browsers have problems
+   * when the step value changes dynamically - they do not adjust the element value correctly, but
+   * instead may set the `stepMismatch` error. If that's the case, the Angular will set the `step`
+   * error on the input, and set the model to `undefined`.
+   *
+   * Note that `input[range]` is not compatible with `ngMax`, `ngMin`, and `ngStep`, because they do
+   * not set the `min` and `max` attributes, which means that the browser won't automatically adjust
+   * the input value based on their values, and will always assume min = 0, max = 100, and step = 1.
+   *
+   * @param           ngInputRange The presense of this attribute enables the built-in support for
+   *                  `input[range]`.
+   * @param {string}  ngModel Assignable angular expression to data-bind to.
+   * @param {string=} name Property name of the form under which the control is published.
+   * @param {string=} min Sets the `min` validation to ensure that the value entered is greater
+   *                  than `min`. Can be interpolated.
+   * @param {string=} max Sets the `max` validation to ensure that the value entered is less than `max`.
+   *                  Can be interpolated.
+   * @param {string=} step Sets the `step` validation to ensure that the value entered matches the `step`
+   *                  Can be interpolated.
+   * @param {string=} ngChange Angular expression to be executed when the ngModel value changes due
+   *                  to user interaction with the input element.
+   * @param {expression=} ngChecked If the expression is truthy, then the `checked` attribute will be set on the
+   *                      element. **Note** : `ngChecked` should not be used alongside `ngModel`.
+   *                      Checkout {@link ng.directive:ngChecked ngChecked} for usage.
+   *
+   * @example
+      <example name="range-input-directive" module="rangeExample">
+        <file name="index.html">
+          <script>
+            angular.module('rangeExample', [])
+              .controller('ExampleController', ['$scope', function($scope) {
+                $scope.value = 75;
+                $scope.min = 10;
+                $scope.max = 90;
+              }]);
+          </script>
+          <form name="myForm" ng-controller="ExampleController">
+
+            Model as range: <input type="range" ng-input-range name="range" ng-model="value" min="{{min}}"  max="{{max}}">
+            <hr>
+            Model as number: <input type="number" ng-model="value"><br>
+            Min: <input type="number" ng-model="min"><br>
+            Max: <input type="number" ng-model="max"><br>
+            value = <code>{{value}}</code><br/>
+            myForm.range.$valid = <code>{{myForm.range.$valid}}</code><br/>
+            myForm.range.$error = <code>{{myForm.range.$error}}</code>
+          </form>
+        </file>
+      </example>
+
+   * ## Range Input with ngMin & ngMax attributes
+
+   * @example
+      <example name="range-input-directive-ng" module="rangeExample">
+        <file name="index.html">
+          <script>
+            angular.module('rangeExample', [])
+              .controller('ExampleController', ['$scope', function($scope) {
+                $scope.value = 75;
+                $scope.min = 10;
+                $scope.max = 90;
+              }]);
+          </script>
+          <form name="myForm" ng-controller="ExampleController">
+            Model as range: <input type="range" ng-input-range name="range" ng-model="value" ng-min="min" ng-max="max">
+            <hr>
+            Model as number: <input type="number" ng-model="value"><br>
+            Min: <input type="number" ng-model="min"><br>
+            Max: <input type="number" ng-model="max"><br>
+            value = <code>{{value}}</code><br/>
+            myForm.range.$valid = <code>{{myForm.range.$valid}}</code><br/>
+            myForm.range.$error = <code>{{myForm.range.$error}}</code>
+          </form>
+        </file>
+      </example>
+
+   */
+  'range': rangeInputType,
 
   /**
    * @ngdoc input