docs(api): add ngRequired to input/select/textarea directives

Closes #1202

src/ng/directive/input.js

@@ -15,7 +15,10 @@ var inputType = {
    *
    * @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=} required Sets `required` validation error key if the value is not entered.
+   * @param {string=} required Adds `required` validation error key if the value is not entered.
+   * @param {string=} ngRequired Adds `required` attribute and `required` validation constraint to
+   *    the element when the ngRequired expression evaluates to true. Use `ngRequired` instead of
+   *    `required` when you want to data-bind to the `required` attribute.
    * @param {number=} ngMinlength Sets `minlength` validation error key if the value is shorter than
    *    minlength.
    * @param {number=} ngMaxlength Sets `maxlength` validation error key if the value is longer than
@@ -85,6 +88,9 @@ var inputType = {
    * @param {string=} min Sets the `min` validation error key if the value entered is less then `min`.
    * @param {string=} max Sets the `max` validation error key if the value entered is greater then `min`.
    * @param {string=} required Sets `required` validation error key if the value is not entered.
+   * @param {string=} ngRequired Adds `required` attribute and `required` validation constraint to
+   *    the element when the ngRequired expression evaluates to true. Use `ngRequired` instead of
+   *    `required` when you want to data-bind to the `required` attribute.
    * @param {number=} ngMinlength Sets `minlength` validation error key if the value is shorter than
    *    minlength.
    * @param {number=} ngMaxlength Sets `maxlength` validation error key if the value is longer than
@@ -151,6 +157,9 @@ var inputType = {
    * @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=} required Sets `required` validation error key if the value is not entered.
+   * @param {string=} ngRequired Adds `required` attribute and `required` validation constraint to
+   *    the element when the ngRequired expression evaluates to true. Use `ngRequired` instead of
+   *    `required` when you want to data-bind to the `required` attribute.
    * @param {number=} ngMinlength Sets `minlength` validation error key if the value is shorter than
    *    minlength.
    * @param {number=} ngMaxlength Sets `maxlength` validation error key if the value is longer than
@@ -216,6 +225,9 @@ var inputType = {
    * @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=} required Sets `required` validation error key if the value is not entered.
+   * @param {string=} ngRequired Adds `required` attribute and `required` validation constraint to
+   *    the element when the ngRequired expression evaluates to true. Use `ngRequired` instead of
+   *    `required` when you want to data-bind to the `required` attribute.
    * @param {number=} ngMinlength Sets `minlength` validation error key if the value is shorter than
    *    minlength.
    * @param {number=} ngMaxlength Sets `maxlength` validation error key if the value is longer than
@@ -638,6 +650,9 @@ function checkboxInputType(scope, element, attr, ctrl) {
  * @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=} required Sets `required` validation error key if the value is not entered.
+ * @param {string=} ngRequired Adds `required` attribute and `required` validation constraint to
+ *    the element when the ngRequired expression evaluates to true. Use `ngRequired` instead of
+ *    `required` when you want to data-bind to the `required` attribute.
  * @param {number=} ngMinlength Sets `minlength` validation error key if the value is shorter than
  *    minlength.
  * @param {number=} ngMaxlength Sets `maxlength` validation error key if the value is longer than
@@ -662,6 +677,7 @@ function checkboxInputType(scope, element, attr, ctrl) {
  * @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=} required Sets `required` validation error key if the value is not entered.
+ * @param {boolean=} ngRequired Sets `required` attribute if set to true
  * @param {number=} ngMinlength Sets `minlength` validation error key if the value is shorter than
  *    minlength.
  * @param {number=} ngMaxlength Sets `maxlength` validation error key if the value is longer than

src/ng/directive/select.js

@@ -29,6 +29,9 @@
  *
  * @param {string} name assignable expression to data-bind to.
  * @param {string=} required The control is considered valid only if value is entered.
+ * @param {string=} ngRequired Adds `required` attribute and `required` validation constraint to
+ *    the element when the ngRequired expression evaluates to true. Use `ngRequired` instead of
+ *    `required` when you want to data-bind to the `required` attribute.
  * @param {comprehension_expression=} ngOptions in one of the following forms:
  *
  *   * for array data sources: