src/ngAria/aria.js
'use strict';
/**
* @ngdoc module
* @name ngAria
* @description
*
* The `ngAria` module provides support for common
* [<abbr title="Accessible Rich Internet Applications">ARIA</abbr>](http://www.w3.org/TR/wai-aria/)
* attributes that convey state or semantic information about the application for users
* of assistive technologies, such as screen readers.
*
* ## Usage
*
* For ngAria to do its magic, simply include the module `ngAria` as a dependency. The following
* directives are supported:
* `ngModel`, `ngChecked`, `ngReadonly`, `ngRequired`, `ngValue`, `ngDisabled`, `ngShow`, `ngHide`,
* `ngClick`, `ngDblClick`, and `ngMessages`.
*
* Below is a more detailed breakdown of the attributes handled by ngAria:
*
* | Directive | Supported Attributes |
* |---------------------------------------------|-----------------------------------------------------------------------------------------------------|
* | {@link ng.directive:ngModel ngModel} | aria-checked, aria-valuemin, aria-valuemax, aria-valuenow, aria-invalid, aria-required, input roles |
* | {@link ng.directive:ngDisabled ngDisabled} | aria-disabled |
* | {@link ng.directive:ngRequired ngRequired} | aria-required |
* | {@link ng.directive:ngChecked ngChecked} | aria-checked |
* | {@link ng.directive:ngReadonly ngReadonly} | aria-readonly |
* | {@link ng.directive:ngValue ngValue} | aria-checked |
* | {@link ng.directive:ngShow ngShow} | aria-hidden |
* | {@link ng.directive:ngHide ngHide} | aria-hidden |
* | {@link ng.directive:ngDblclick ngDblclick} | tabindex |
* | {@link module:ngMessages ngMessages} | aria-live |
* | {@link ng.directive:ngClick ngClick} | tabindex, keydown event, button role |
*
* Find out more information about each directive by reading the
* {@link guide/accessibility ngAria Developer Guide}.
*
* ## Example
* Using ngDisabled with ngAria:
* ```html
* <md-checkbox ng-disabled="disabled">
* ```
* Becomes:
* ```html
* <md-checkbox ng-disabled="disabled" aria-disabled="true">
* ```
*
* ## Disabling Specific Attributes
* It is possible to disable individual attributes added by ngAria with the
* {@link ngAria.$ariaProvider#config config} method. For more details, see the
* {@link guide/accessibility Developer Guide}.
*
* ## Disabling `ngAria` on Specific Elements
* It is possible to make `ngAria` ignore a specific element, by adding the `ng-aria-disable`
* attribute on it. Note that only the element itself (and not its child elements) will be ignored.
*/
var ARIA_DISABLE_ATTR = 'ngAriaDisable';
var ngAriaModule = angular.module('ngAria', ['ng']).
info({ angularVersion: '"NG_VERSION_FULL"' }).
provider('$aria', $AriaProvider);
/**
* Internal Utilities
*/
var nativeAriaNodeNames = ['BUTTON', 'A', 'INPUT', 'TEXTAREA', 'SELECT', 'DETAILS', 'SUMMARY'];
var isNodeOneOf = function(elem, nodeTypeArray) {
if (nodeTypeArray.indexOf(elem[0].nodeName) !== -1) {
return true;
}
};
/**
* @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 $ariaProvider#config
*
* @param {object} config object to enable/disable specific ARIA attributes
*
* - **ariaHidden** – `{boolean}` – Enables/disables aria-hidden tags
* - **ariaChecked** – `{boolean}` – Enables/disables aria-checked tags
* - **ariaReadonly** – `{boolean}` – Enables/disables aria-readonly tags
* - **ariaDisabled** – `{boolean}` – Enables/disables aria-disabled tags
* - **ariaRequired** – `{boolean}` – Enables/disables aria-required tags
* - **ariaInvalid** – `{boolean}` – Enables/disables aria-invalid tags
* - **ariaValue** – `{boolean}` – Enables/disables aria-valuemin, aria-valuemax and
* aria-valuenow tags
* - **tabindex** – `{boolean}` – Enables/disables tabindex tags
* - **bindKeydown** – `{boolean}` – Enables/disables keyboard event binding on non-interactive
* elements (such as `div` or `li`) using ng-click, making them more accessible to users of
* assistive technologies
* - **bindRoleForClick** – `{boolean}` – Adds role=button to non-interactive elements (such as
* `div` or `li`) using ng-click, making them more accessible to users of assistive
* technologies
*
* @description
* Enables/disables various ARIA attributes
*/
this.config = function(newConfig) {
config = angular.extend(config, newConfig);
};
function watchExpr(attrName, ariaAttr, nativeAriaNodeNames, negate) {
return function(scope, elem, attr) {
if (attr.hasOwnProperty(ARIA_DISABLE_ATTR)) return;
var ariaCamelName = attr.$normalize(ariaAttr);
if (config[ariaCamelName] && !isNodeOneOf(elem, nativeAriaNodeNames) && !attr[ariaCamelName]) {
scope.$watch(attr[attrName], function(boolVal) {
// ensure boolean value
boolVal = negate ? !boolVal : !!boolVal;
elem.attr(ariaAttr, boolVal);
});
}
};
}
/**
* @ngdoc service
* @name $aria
*
* @description
*
* 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.$$watchExpr('ngDisabled', 'aria-disabled', nativeAriaNodeNames, false);
* }])
*```
* Shown above, the ngAria module creates a directive with the same signature as the
* traditional `ng-disabled` directive. But this ngAria version is dedicated to
* solely managing accessibility attributes on custom elements. The internal `$aria` service is
* used to watch the boolean attribute `ngDisabled`. If it has not been explicitly set by the
* developer, `aria-disabled` is injected as an attribute with its value synchronized to the
* value in `ngDisabled`.
*
* Because ngAria hooks into the `ng-disabled` directive, developers do not have to do
* anything to enable this feature. The `aria-disabled` attribute is automatically managed
* simply as a silent side-effect of using `ng-disabled` with the ngAria module.
*
* The full list of directives that interface with ngAria:
* * **ngModel**
* * **ngChecked**
* * **ngReadonly**
* * **ngRequired**
* * **ngDisabled**
* * **ngValue**
* * **ngShow**
* * **ngHide**
* * **ngClick**
* * **ngDblclick**
* * **ngMessages**
*
* Read the {@link guide/accessibility ngAria Developer Guide} for a thorough explanation of each
* directive.
*
*
* ## Dependencies
* Requires the {@link ngAria} module to be installed.
*/
this.$get = function() {
return {
config: function(key) {
return config[key];
},
$$watchExpr: watchExpr
};
};
}
ngAriaModule.directive('ngShow', ['$aria', function($aria) {
return $aria.$$watchExpr('ngShow', 'aria-hidden', [], true);
}])
.directive('ngHide', ['$aria', function($aria) {
return $aria.$$watchExpr('ngHide', 'aria-hidden', [], false);
}])
.directive('ngValue', ['$aria', function($aria) {
return $aria.$$watchExpr('ngValue', 'aria-checked', nativeAriaNodeNames, false);
}])
.directive('ngChecked', ['$aria', function($aria) {
return $aria.$$watchExpr('ngChecked', 'aria-checked', nativeAriaNodeNames, false);
}])
.directive('ngReadonly', ['$aria', function($aria) {
return $aria.$$watchExpr('ngReadonly', 'aria-readonly', nativeAriaNodeNames, false);
}])
.directive('ngRequired', ['$aria', function($aria) {
return $aria.$$watchExpr('ngRequired', 'aria-required', nativeAriaNodeNames, false);
}])
.directive('ngModel', ['$aria', function($aria) {
function shouldAttachAttr(attr, normalizedAttr, elem, allowNonAriaNodes) {
return $aria.config(normalizedAttr) &&
!elem.attr(attr) &&
(allowNonAriaNodes || !isNodeOneOf(elem, nativeAriaNodeNames)) &&
(elem.attr('type') !== 'hidden' || elem[0].nodeName !== 'INPUT');
}
function shouldAttachRole(role, elem) {
// if element does not have role attribute
// AND element type is equal to role (if custom element has a type equaling shape) <-- remove?
// AND element is not in nativeAriaNodeNames
return !elem.attr('role') && (elem.attr('type') === role) && !isNodeOneOf(elem, nativeAriaNodeNames);
}
function getShape(attr, elem) {
var type = attr.type,
role = attr.role;
return ((type || role) === 'checkbox' || role === 'menuitemcheckbox') ? 'checkbox' :
((type || role) === 'radio' || role === 'menuitemradio') ? 'radio' :
(type === 'range' || role === 'progressbar' || role === 'slider') ? 'range' : '';
}
return {
restrict: 'A',
require: 'ngModel',
priority: 200, //Make sure watches are fired after any other directives that affect the ngModel value
compile: function(elem, attr) {
if (attr.hasOwnProperty(ARIA_DISABLE_ATTR)) return;
var shape = getShape(attr, elem);
return {
post: function(scope, elem, attr, ngModel) {
var needsTabIndex = shouldAttachAttr('tabindex', 'tabindex', elem, false);
function ngAriaWatchModelValue() {
return ngModel.$modelValue;
}
function getRadioReaction(newVal) {
// Strict comparison would cause a BC
// eslint-disable-next-line eqeqeq
var boolVal = (attr.value == ngModel.$viewValue);
elem.attr('aria-checked', boolVal);
}
function getCheckboxReaction() {
elem.attr('aria-checked', !ngModel.$isEmpty(ngModel.$viewValue));
}
switch (shape) {
case 'radio':
case 'checkbox':
if (shouldAttachRole(shape, elem)) {
elem.attr('role', shape);
}
if (shouldAttachAttr('aria-checked', 'ariaChecked', elem, false)) {
scope.$watch(ngAriaWatchModelValue, shape === 'radio' ?
getRadioReaction : getCheckboxReaction);
}
if (needsTabIndex) {
elem.attr('tabindex', 0);
}
break;
case 'range':
if (shouldAttachRole(shape, elem)) {
elem.attr('role', 'slider');
}
if ($aria.config('ariaValue')) {
var needsAriaValuemin = !elem.attr('aria-valuemin') &&
(attr.hasOwnProperty('min') || attr.hasOwnProperty('ngMin'));
var needsAriaValuemax = !elem.attr('aria-valuemax') &&
(attr.hasOwnProperty('max') || attr.hasOwnProperty('ngMax'));
var needsAriaValuenow = !elem.attr('aria-valuenow');
if (needsAriaValuemin) {
attr.$observe('min', function ngAriaValueMinReaction(newVal) {
elem.attr('aria-valuemin', newVal);
});
}
if (needsAriaValuemax) {
attr.$observe('max', function ngAriaValueMinReaction(newVal) {
elem.attr('aria-valuemax', newVal);
});
}
if (needsAriaValuenow) {
scope.$watch(ngAriaWatchModelValue, function ngAriaValueNowReaction(newVal) {
elem.attr('aria-valuenow', newVal);
});
}
}
if (needsTabIndex) {
elem.attr('tabindex', 0);
}
break;
}
if (!attr.hasOwnProperty('ngRequired') && ngModel.$validators.required
&& shouldAttachAttr('aria-required', 'ariaRequired', elem, false)) {
// ngModel.$error.required is undefined on custom controls
attr.$observe('required', function() {
elem.attr('aria-required', !!attr['required']);
});
}
if (shouldAttachAttr('aria-invalid', 'ariaInvalid', elem, true)) {
scope.$watch(function ngAriaInvalidWatch() {
return ngModel.$invalid;
}, function ngAriaInvalidReaction(newVal) {
elem.attr('aria-invalid', !!newVal);
});
}
}
};
}
};
}])
.directive('ngDisabled', ['$aria', function($aria) {
return $aria.$$watchExpr('ngDisabled', 'aria-disabled', nativeAriaNodeNames, false);
}])
.directive('ngMessages', function() {
return {
restrict: 'A',
require: '?ngMessages',
link: function(scope, elem, attr, ngMessages) {
if (attr.hasOwnProperty(ARIA_DISABLE_ATTR)) return;
if (!elem.attr('aria-live')) {
elem.attr('aria-live', 'assertive');
}
}
};
})
.directive('ngClick',['$aria', '$parse', function($aria, $parse) {
return {
restrict: 'A',
compile: function(elem, attr) {
if (attr.hasOwnProperty(ARIA_DISABLE_ATTR)) return;
var fn = $parse(attr.ngClick);
return function(scope, elem, attr) {
if (!isNodeOneOf(elem, nativeAriaNodeNames)) {
if ($aria.config('bindRoleForClick') && !elem.attr('role')) {
elem.attr('role', 'button');
}
if ($aria.config('tabindex') && !elem.attr('tabindex')) {
elem.attr('tabindex', 0);
}
if ($aria.config('bindKeydown') && !attr.ngKeydown && !attr.ngKeypress && !attr.ngKeyup) {
elem.on('keydown', function(event) {
var keyCode = event.which || event.keyCode;
if (keyCode === 13 || keyCode === 32) {
// If the event is triggered on a non-interactive element ...
if (nativeAriaNodeNames.indexOf(event.target.nodeName) === -1 && !event.target.isContentEditable) {
// ... prevent the default browser behavior (e.g. scrolling when pressing spacebar)
// See https://github.com/angular/angular.js/issues/16664
event.preventDefault();
}
scope.$apply(callback);
}
function callback() {
fn(scope, { $event: event });
}
});
}
}
};
}
};
}])
.directive('ngDblclick', ['$aria', function($aria) {
return function(scope, elem, attr) {
if (attr.hasOwnProperty(ARIA_DISABLE_ATTR)) return;
if ($aria.config('tabindex') && !elem.attr('tabindex') && !isNodeOneOf(elem, nativeAriaNodeNames)) {
elem.attr('tabindex', 0);
}
};
}]);