docs(ngAria): Add Usage Details and Examples

Closes #10031
This commit is contained in:
Marcy Sutton
2014-11-12 11:56:26 -08:00
committed by Caitlin Potter
parent 9d1e87a3f1
commit 5b23bc9b07
3 changed files with 316 additions and 47 deletions

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@@ -161,6 +161,27 @@ or JavaScript callbacks.
</tr>
</table>
## {@link ngAria ngAria}
Use ngAria to inject common accessibility attributes into directives and improve the experience for users with disabilities.
<div class="alert alert-info">Include the **angular-aria.js** file and set ngAria as a dependency for this to work in your application.</div>
<table class="definition-table spaced">
<tr>
<td>
{@link ngAria#service Services}
</td>
<td>
<p>
The {@link ngAria.$aria $aria} service contains helper methods for applying ARIA attributes to HTML.
<p>
<p>
{@link ngAria.$ariaProvider $ariaProvider} is used for configuring ARIA attributes.
</p>
</td>
</tr>
</table>
## {@link ngResource ngResource}

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@@ -12,7 +12,7 @@ assistive technologies used by persons with disabilities.
##Including ngAria
Using ngAria is as simple as requiring the ngAria module in your application. ngAria hooks into
Using {@link ngAria ngAria} is as simple as requiring the ngAria module in your application. ngAria hooks into
standard AngularJS directives and quietly injects accessibility support into your application
at runtime.
@@ -20,6 +20,15 @@ at runtime.
angular.module('myApp', ['ngAria'])...
```
###Using ngAria
Most of what ngAria does is only visible "under the hood". To see the module in action, once you've
added it as a dependency, you can test a few things:
* Using your favorite element inspector, look for ngAria attributes in your own code.
* Test using your keyboard to ensure `tabindex` is used correctly.
* Fire up a screen reader such as VoiceOver to listen for ARIA support.
[Helpful screen reader tips.](http://webaim.org/articles/screenreader_testing/)
##Supported directives
Currently, ngAria interfaces with the following directives:
* <a href="#ngmodel">ngModel</a>
@@ -31,7 +40,7 @@ Currently, ngAria interfaces with the following directives:
<h2 id="ngmodel">ngModel</h2>
Most of ngAria's heavy lifting happens in the [ngModel](https://docs.angularjs.org/api/ng/directive/ngModel)
Most of ngAria's heavy lifting happens in the {@link ngModel ngModel}
directive. For elements using ngModel, special attention is paid by ngAria if that element also
has a a role or type of `checkbox`, `radio`, `range` or `textbox`.
@@ -47,15 +56,80 @@ attributes (if they have not been explicitly specified by the developer):
###Example
```html
<md-checkbox ng-model="val" required>
```
Becomes:
```html
<md-checkbox ng-model="val" required aria-required="true" tabIndex="0">
```
<example module="ngAria_ngModelExample" deps="angular-aria.js">
<file name="index.html">
<style>
[role=checkbox] {
cursor: pointer;
display: inline-block;
}
[role=checkbox] .icon:before {
content: '\2610';
display: inline-block;
font-size: 2em;
line-height: 1;
vertical-align: middle;
speak: none;
}
[role=checkbox].active .icon:before {
content: '\2611';
}
pre {
white-space: pre-wrap;
}
</style>
<div>
<form ng-controller="formsController">
<some-checkbox role="checkbox" ng-model="checked" ng-class="{active: checked}"
ng-disabled="isDisabled" ng-click="toggleCheckbox()"
aria-label="Custom Checkbox" show-attrs>
<span class="icon" aria-hidden="true"></span>
Custom Checkbox
</some-checkbox>
</form>
</div>
<script>
var app = angular.module('ngAria_ngModelExample', ['ngAria'])
.controller('formsController', function($scope){
$scope.checked = false;
$scope.toggleCheckbox = function(){
$scope.checked = !$scope.checked;
}
})
.directive('someCheckbox', function(){
return {
restrict: 'E',
link: function($scope, $el, $attrs) {
$el.on('keypress', function(event){
event.preventDefault();
if(event.keyCode === 32 || event.keyCode === 13){
$scope.toggleCheckbox();
$scope.$apply();
}
});
}
}
})
.directive('showAttrs', function() {
return function($scope, $el, $attrs) {
var pre = document.createElement('pre');
$el.after(pre);
$scope.$watch(function() {
var $attrs = {};
Array.prototype.slice.call($el[0].attributes, 0).forEach(function(item) {
if (item.name !== 'show-$attrs') {
$attrs[item.name] = item.value;
}
});
return $attrs;
}, function(newAttrs, oldAttrs) {
pre.textContent = JSON.stringify(newAttrs, null, 2);
}, true);
}
});
</script>
</file>
</example>
ngAria will also add `tabIndex`, ensuring custom elements with these roles will be reachable from
the keyboard. It is still up to **you** as a developer to **ensure custom controls will be
@@ -106,6 +180,24 @@ screen reader users won't accidentally focus on "mystery elements". Managing tab
child control can be complex and affect performance, so its best to just stick with the default
`display: none` CSS. See the [fourth rule of ARIA use](http://www.w3.org/TR/aria-in-html/#fourth-rule-of-aria-use).
###Example
```css
.ng-hide {
display: block;
opacity: 0;
}
```
```html
<div ng-show="false" class="ng-hide" aria-hidden="true"></div>
```
Becomes:
```html
<div ng-show="true" aria-hidden="false"></div>
```
*Note: Child links, buttons or other interactive controls must also be removed from the tab order.*
<h2 id="nghide">ngHide</h2>
>The [ngHide](https://docs.angularjs.org/api/ng/directive/ngHide) directive shows or hides the
@@ -116,12 +208,22 @@ The default CSS for `ngHide`, the inverse method to `ngShow`, makes ngAria redun
`aria-hidden` on the directive when it is hidden or shown, but the content is already hidden with
`display: none`. See explanation for <a href="#ngshow">ngShow</a> when overriding the default CSS.
<h2 id="ngclick">ngClick and ngDblClick</h2>
If `ngClick` or `ngDblClick` is encountered, ngAria will add `tabIndex` if it isn't there already.
Even with this, you must currently still add `ng-keypress` to non-interactive elements such as
`<div>` or `<taco-button>` to enable keyboard access. Conversation is
[currently ongoing](https://github.com/angular/angular.js/issues/9254) about whether ngAria
should also bind `ng-keypress` to be more useful.
<h2 id="ngclick-and-ngdblclick">ngClick and ngDblclick</h2>
If `ng-click` or `ng-dblclick` is encountered, ngAria will add `tabindex` if it isn't there already.
Even with this, you must currently still add `ng-keypress` to non-interactive elements such as `div`
or `taco-button` to enable keyboard access. Conversation is currently ongoing about whether ngAria
should also bind `ng-keypress`.
<h3>Example</h3>
```html
<div ng-click="toggleMenu()"></div>
```
Becomes:
```html
<div ng-click="toggleMenu()" tabindex="0"></div>
```
*Note: ngAria still requires `ng-keypress` to be added manually to non-native controls like divs.*
<h2 id="ngmessages">ngMessages</h2>
@@ -129,20 +231,105 @@ The new ngMessages module makes it easy to display form validation or other mess
sequencing and animation. To expose these visual messages to screen readers,
ngAria injects `aria-live="polite"`, causing them to be read aloud any time a message is shown,
regardless of the user's focus location.
###Example
* * *
```html
<div ng-messages="myForm.myName.$error">
<div ng-message="required">You did not enter a field</div>
<div ng-message="maxlength">Your field is too long</div>
</div>
```
Becomes:
```html
<div ng-messages="myForm.myName.$error" aria-live="polite">
<div ng-message="required">You did not enter a field</div>
<div ng-message="maxlength">Your field is too long</div>
</div>
```
##Disabling attributes
The attribute magic of ngAria may not work for every scenario. To disable individual attributes,
you can use the {@link ngAria.$ariaProvider#config config} method:
you can use the {@link ngAria.$ariaProvider#config config} method. Just keep in mind this will
tell ngAria to ignore the attribute globally.
```
angular.module('myApp', ['ngAria'], function config($ariaProvider) {
$ariaProvider.config({
tabindex: false
<example module="ngAria_ngDisabledExample" deps="angular-aria.js">
<file name="index.html">
<style>
[role=checkbox] {
cursor: pointer;
display: inline-block;
}
[role=checkbox] .icon:before {
content: '\2610';
display: inline-block;
font-size: 2em;
line-height: 1;
vertical-align: middle;
speak: none;
}
[role=checkbox].active .icon:before {
content: '\2611';
}
</style>
<form ng-controller="formsController">
<div ng-model="someModel" show-attrs>
Div with ngModel and aria-invalid disabled
</div>
<div role="checkbox" ng-model="checked" ng-class="{active: checked}"
aria-label="Custom Checkbox" ng-click="toggleCheckbox()" some-checkbox show-attrs>
<span class="icon" aria-hidden="true"></span>
Custom Checkbox for comparison
</div>
</form>
<script>
angular.module('ngAria_ngDisabledExample', ['ngAria'], function config($ariaProvider) {
$ariaProvider.config({
ariaInvalid: false,
tabindex: true
});
})
.controller('formsController', function($scope){
$scope.checked = false;
$scope.toggleCheckbox = function(){
$scope.checked = !$scope.checked;
}
})
.directive('someCheckbox', function(){
return {
restrict: 'A',
link: function($scope, $el, $attrs) {
$el.on('keypress', function(event){
event.preventDefault();
if(event.keyCode === 32 || event.keyCode === 13){
$scope.toggleCheckbox();
$scope.$apply();
}
});
}
}
})
.directive('showAttrs', function() {
return function(scope, el, attrs) {
var pre = document.createElement('pre');
el.after(pre);
scope.$watch(function() {
var attrs = {};
Array.prototype.slice.call(el[0].attributes, 0).forEach(function(item) {
if (item.name !== 'show-attrs') {
attrs[item.name] = item.value;
}
});
return attrs;
}, function(newAttrs, oldAttrs) {
pre.textContent = JSON.stringify(newAttrs, null, 2);
}, true);
}
});
});
```
</script>
</file>
</example>
##Common Accessibility Patterns
@@ -171,6 +358,7 @@ Accessibility best practices that apply to web apps in general also apply to Ang
* [Using ARIA in HTML](http://www.w3.org/TR/aria-in-html/)
* [AngularJS Accessibility at ngEurope](https://www.youtube.com/watch?v=dmYDggEgU-s&list=UUEGUP3TJJfMsEM_1y8iviSQ)
* [Testing with Screen Readers](http://webaim.org/articles/screenreader_testing/)
* [Chrome Accessibility Developer Tools](https://chrome.google.com/webstore/detail/accessibility-developer-t/fpkknkljclfencbdbgkenhalefipecmb?hl=en)
* [W3C Accessibility Testing](http://www.w3.org/wiki/Accessibility_testing)
* [WebAIM](http://webaim.org)