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问题:
I'm building an accessible website and trying to manage focus. I need to open a modal and then put focus on the first element in the modal then trap the focus until the modal is closed ("canceled" or "accepted").
HTML
<a href="" ng-click="modalshow = !modalshow; modal.open();">Open Modal</a> <div ng-show="modalshow" id="modal"> <h3 id="tofs" >Terms of Service</h3> <p>Lorem Ipsum Lorem Ipsum Lorem Ipsum Lorem Ipsum </p> <span>Cancel</span> <span>Accept/span> </div> <h2>Seprate Content</h2>
Javascript
angular.module('app') .controller('Controller', modalCtrl); function modalCtrl() { $scope.modal = { open: function() { angular.element('#tofs').focus(); } } }
回答1:
angular.element("html").on("focusin", "body", function (event) { if(angular.element("#modal:visible").length>0){ event.preventDefault(); event.stopPropagation(); angular.element('#tofs').focus(); } });
you can add this code to trap all focus events to h3 tag when modal is visible.
回答2:
There's a directive called ngBlur, that fires an event when an element loses focus. Try executing your focus function on ng-blur
Here: https://docs.angularjs.org/api/ng/directive/ngBlur
An example: http://jsbin.com/hemaye/1/edit?html,js,output
You cannot ever select the 2nd input box because of the ng-blur statement
回答3:
There is multiple possibility to trap the focus.
One solution is to manually set tabindex="-1"
temporarily on all the elements in the background of your modal when it is showed (and remove this tabindex, or revert to original tabindex when leaving modal).
Another solution is to look at how angular-bootstrap plan to fix this issue : https://github.com/angular-ui/bootstrap/issues/738
You can also look at the WAI ARIA page, they have a related content about it : http://www.w3.org/TR/wai-aria-practices/#trap_focus_div
回答4:
Okay after way too much searching, this is what I came up with. Basically I created ng-focus functions on the last element in the modal and the next element following the modal. This way I could check if the focus existed within the modal and if not, I would loop the focus back to the top.
<a href="" ng-click="modalshow = !modalshow; modal.open();">Open Modal</a> <div ng-show="modalshow" id="modal"> <h3 id="tofs" >Terms of Service</h3> <p>Lorem Ipsum Lorem Ipsum Lorem Ipsum Lorem Ipsum </p> <a href="" ng-focus="modalshow.onFocus($event)">Cancel</a> <a href="" ng-focus="modalshow.onFocus($event)">Accept</a> </div> <h2>Seprate Content</h2> <a href="" ng-focus="modalshow.onFocus($event)">next link<a>
Javascript
angular.module('app') .controller('Controller', modalCtrl); function modalCtrl() { $scope.modal = { open: function() { angular.element('#tofs').focus(); }, onFocus: function(){ var modal = angular.element('#modal')[0]; if (!modal.contains( event.target ) && $scope.modalIsOpen) { event.stopPropagation(); angular.element('#tofs').focus(); } } } }
回答5:
Don't use any solution requiring you to look up "tabbable" elements. Instead, use keydown
and either click
events or a backdrop in an effective manor.
What you need to do is have a general window.keydown
event with preventDefault()
to stop all tabbing when the modal is displayed and a keydown.tab
event with stopPropagation()
to handle tabbing for the modal.
You can use click
events in a similar manor or you can just use a backdrop to prevent clicking elements behind it.
For Angular1, I'd imagine this would look similar to Asheesh Kumar's answer. You can see my Angular2-x solution here: https://stackoverflow.com/a/46738489/1754995