feat(accordion): add aria tags

- Improve accessibility of accordion

Closes #5338

src/accordion/accordion.js

@@ -91,6 +91,10 @@ angular.module('ui.bootstrap.accordion', ['ui.bootstrap.collapse'])
           }
         }
       };
+
+      var id = 'accordiongroup-' + scope.$id + '-' + Math.floor(Math.random() * 10000);
+      scope.headingId = id + '-tab';
+      scope.panelId = id + '-panel';
     }
   };
 })

src/accordion/test/accordion.spec.js

@@ -123,6 +123,12 @@ describe('uib-accordion', function() {
       $templateCache = _$templateCache_;
     }));
 
+    it('should be a tablist', function() {
+      element = $compile('<uib-accordion></uib-accordion>')(scope);
+      scope.$digest();
+      expect(element.html()).toContain('role="tablist"');
+    });
+
     it('should expose the controller on the view', function() {
       $templateCache.put('uib/template/accordion/accordion.html', '<div>{{accordion.text}}</div>');
 
@@ -150,6 +156,9 @@ describe('uib-accordion', function() {
   describe('uib-accordion-group', function() {
     var scope, $compile;
     var element, groups;
+    var findGroupHeading = function(index) {
+      return groups.eq(index).find('.panel-heading').eq(0);
+    };
     var findGroupLink = function(index) {
       return groups.eq(index).find('.accordion-toggle').eq(0);
     };
@@ -177,6 +186,7 @@ describe('uib-accordion', function() {
 
     describe('with static panels', function() {
       beforeEach(function() {
+        spyOn(Math, 'random').and.returnValue(0.1);
         var tpl =
           '<uib-accordion>' +
             '<uib-accordion-group heading="title 1">Content 1</uib-accordion-group>' +
@@ -204,20 +214,26 @@ describe('uib-accordion', function() {
         findGroupLink(0).click();
         scope.$digest();
         expect(findGroupBody(0).scope().isOpen).toBe(true);
+        expect(findGroupHeading(0).html()).toContain('aria-expanded="true"');
 
         findGroupLink(1).click();
         scope.$digest();
         expect(findGroupBody(0).scope().isOpen).toBe(false);
+        expect(findGroupHeading(0).html()).toContain('aria-expanded="false"');
         expect(findGroupBody(1).scope().isOpen).toBe(true);
+        expect(findGroupHeading(1).html()).toContain('aria-expanded="true"');
       });
 
       it('should toggle element on click', function() {
         findGroupLink(0).click();
         scope.$digest();
         expect(findGroupBody(0).scope().isOpen).toBe(true);
+        expect(groups.eq(0).html()).toContain('aria-hidden="false"');
+
         findGroupLink(0).click();
         scope.$digest();
         expect(findGroupBody(0).scope().isOpen).toBe(false);
+        expect(groups.eq(0).html()).toContain('aria-hidden="true"');
       });
 
       it('should add, by default, "panel-open" when opened', function() {
@@ -256,6 +272,16 @@ describe('uib-accordion', function() {
 
         expect(group).not.toHaveClass('panel-open');
       });
+
+      it('should generate an Id for the heading', function() {
+        var groupScope = findGroupBody(0).scope();
+        expect(groupScope.headingId).toEqual('accordiongroup-' + groupScope.$id + '-1000-tab');
+      });
+
+      it('should generate an Id for the panel', function() {
+        var groupScope = findGroupBody(0).scope();
+        expect(groupScope.panelId).toEqual('accordiongroup-' + groupScope.$id + '-1000-panel');
+      });
     });
 
     describe('with open-class attribute', function() {

template/accordion/accordion-group.html

@@ -1,10 +1,10 @@
 <div class="panel" ng-class="panelClass || 'panel-default'">
-  <div class="panel-heading" ng-keypress="toggleOpen($event)">
+  <div role="tab" id="{{::headingId}}" aria-selected="{{isOpen}}" class="panel-heading" ng-keypress="toggleOpen($event)">
     <h4 class="panel-title">
-      <a href tabindex="0" class="accordion-toggle" ng-click="toggleOpen()" uib-accordion-transclude="heading"><span ng-class="{'text-muted': isDisabled}">{{heading}}</span></a>
+      <a role="button" data-toggle="collapse" href aria-expanded="{{isOpen}}" aria-controls="{{::panelId}}" tabindex="0" class="accordion-toggle" ng-click="toggleOpen()" uib-accordion-transclude="heading"><span ng-class="{'text-muted': isDisabled}">{{heading}}</span></a>
     </h4>
   </div>
-  <div class="panel-collapse collapse" uib-collapse="!isOpen">
-	  <div class="panel-body" ng-transclude></div>
+  <div id="{{::panelId}}" aria-labelledby="{{::headingId}}" aria-hidden="{{!isOpen}}" role="tabpanel" class="panel-collapse collapse" uib-collapse="!isOpen">
+    <div class="panel-body" ng-transclude></div>
   </div>
 </div>

template/accordion/accordion.html

@@ -1 +1 @@
-<div class="panel-group" ng-transclude></div>
+<div role="tablist" class="panel-group" ng-transclude></div>