@ngdoc provider
@name $ariaProvider
@this

@description

Used for configuring the ARIA attributes injected and managed by ngAria.

```js
angular.module('myApp', ['ngAria'], function config($ariaProvider) {
$ariaProvider.config({
ariaValue: true,
tabindex: false
});
});
```

## Dependencies
Requires the {@link ngAria} module to be installed.
function $AriaProvider() {
  var config = {
    ariaHidden: true,
    ariaChecked: true,
    ariaReadonly: true,
    ariaDisabled: true,
    ariaRequired: true,
    ariaInvalid: true,
    ariaValue: true,
    tabindex: true,
    bindKeydown: true,
    bindRoleForClick: true
  };

  /**
   * @ngdoc method
   * @name $ariaProvider#config
   *
   * @param {object} config object to enable/disable specific ARIA attributes
   *
   *  - **ariaHidden** – `{boolean}` – Enables/disables aria-hidden tags
   *  - **ariaChecked** – `{boolean}` – Enables/disables aria-checked tags
   *  - **ariaReadonly** – `{boolean}` – Enables/disables aria-readonly tags
   *  - **ariaDisabled** – `{boolean}` – Enables/disables aria-disabled tags
   *  - **ariaRequired** – `{boolean}` – Enables/disables aria-required tags
   *  - **ariaInvalid** – `{boolean}` – Enables/disables aria-invalid tags
   *  - **ariaValue** – `{boolean}` – Enables/disables aria-valuemin, aria-valuemax and
   *    aria-valuenow tags
   *  - **tabindex** – `{boolean}` – Enables/disables tabindex tags
   *  - **bindKeydown** – `{boolean}` – Enables/disables keyboard event binding on non-interactive
   *    elements (such as `div` or `li`) using ng-click, making them more accessible to users of
   *    assistive technologies
   *  - **bindRoleForClick** – `{boolean}` – Adds role=button to non-interactive elements (such as
   *    `div` or `li`) using ng-click, making them more accessible to users of assistive
   *    technologies
   *
   * @description
   * Enables/disables various ARIA attributes
   */
  this.config = function(newConfig) {
    config = angular.extend(config, newConfig);
  };

  function watchExpr(attrName, ariaAttr, nodeBlackList, negate) {
    return function(scope, elem, attr) {
      if (attr.hasOwnProperty(ARIA_DISABLE_ATTR)) return;

      var ariaCamelName = attr.$normalize(ariaAttr);
      if (config[ariaCamelName] && !isNodeOneOf(elem, nodeBlackList) && !attr[ariaCamelName]) {
        scope.$watch(attr[attrName], function(boolVal) {
          // ensure boolean value
          boolVal = negate ? !boolVal : !!boolVal;
          elem.attr(ariaAttr, boolVal);
        });
      }
    };
  }
  /**
   * @ngdoc service
   * @name $aria
   *
   * @description
   * @priority 200
   *
   * The $aria service contains helper methods for applying common
   * [ARIA](http://www.w3.org/TR/wai-aria/) attributes to HTML directives.
   *
   * ngAria injects common accessibility attributes that tell assistive technologies when HTML
   * elements are enabled, selected, hidden, and more. To see how this is performed with ngAria,
   * let's review a code snippet from ngAria itself:
   *
   *```js
   * ngAriaModule.directive('ngDisabled', ['$aria', function($aria) {
   *   return $aria.$$watchExpr('ngDisabled', 'aria-disabled', nodeBlackList, false);
   * }])
   *```
   * Shown above, the ngAria module creates a directive with the same signature as the
   * traditional `ng-disabled` directive. But this ngAria version is dedicated to
   * solely managing accessibility attributes on custom elements. The internal `$aria` service is
   * used to watch the boolean attribute `ngDisabled`. If it has not been explicitly set by the
   * developer, `aria-disabled` is injected as an attribute with its value synchronized to the
   * value in `ngDisabled`.
   *
   * Because ngAria hooks into the `ng-disabled` directive, developers do not have to do
   * anything to enable this feature. The `aria-disabled` attribute is automatically managed
   * simply as a silent side-effect of using `ng-disabled` with the ngAria module.
   *
   * The full list of directives that interface with ngAria:
   * * **ngModel**
   * * **ngChecked**
   * * **ngReadonly**
   * * **ngRequired**
   * * **ngDisabled**
   * * **ngValue**
   * * **ngShow**
   * * **ngHide**
   * * **ngClick**
   * * **ngDblclick**
   * * **ngMessages**
   *
   * Read the {@link guide/accessibility ngAria Developer Guide} for a thorough explanation of each
   * directive.
   *
   *
   * ## Dependencies
   * Requires the {@link ngAria} module to be installed.
   */
  this.$get = function() {
    return {
      config: function(key) {
        return config[key];
      },
      $$watchExpr: watchExpr
    };
  };
}