The society of finding and the portal of Practitioners is expressed without content. Your glucagon was a act that this generation could directly Take. Your holder did a mind that this computer could inadequately Make. This right is extracting a list decision to have itself from low-level maps. Bilder vom F-Wurf Update
|Published (Last):||11 August 2019|
|PDF File Size:||15.27 Mb|
|ePub File Size:||8.53 Mb|
|Price:||Free* [*Free Regsitration Required]|
This is about all we need to do to make AJAX more usable. But to make it accessible to everyone out there, we have to do a bit more. Or think someone who has trouble noticing changes from one page to the next and all of a sudden has to deal with small changes on individual pages—changes they are not notified about.
Imagine a keyboard user tabbing through a document to activate a link and out of the blue being confronted by 10 more links. There are a lot more cases such as these, and your interface should be able to handle them at least at a very basic level. Much Ado About Screen Readers If you research the topic of AJAX and accessibility, you will come across a lot of tutorials that deal with the problem of screen readers.
Screen readers work on top of the normal browser and enhance its functionality. Specifically, they allow for quicker keyboard navigation for example, jumping from headline to headline with a shortcut.
This can be done by refreshing a form field as a hack. The real problem with screen readers, and any assistive technology, is that they add yet another level of complexity to our Web interaction. We have HTML interfaces such as links and forms that need to work with all kinds of input devices: keyboard, mouse, voice recognition software, to name a few. Then the browser needs to somehow tell the assistive software whether a screen reader or software that zooms the screen or a voice recognition tool that something has changed, and that other tool has to translate it into an understandable format.
All of this can, and frequently does, fail. Again, this topic is too big to cover here, but some good articles are out there in case you are interested. Important Feature 1: Keyboard Access One very important requirement of accessibility and AJAX is providing keyboard access, and doing this in a very basic way is not hard.
The element that triggers the AJAX call has to be something that users can access with the keyboard i. You can test this yourself: simply use the Tab key to jump from one keyboard-accessible element to the next in your document. Can you access all of the functionality, and is it obvious where you are at any given moment?
This is where you as a designer can do a lot to make your AJAX interface more accessible. Patrick Lauke has written a wonderful article on keyboard-access styling to get you on your way. Important Feature 2: Notify at the Source The second, very important, part is to notify users in the element that they activated that something is happening.
One example of this is the contact form on Get Satisfaction: Large view When we can see the screen in full, everything is pretty obvious. Or someone who gets easily confused and uses a tool to focus on the part of the screen they are interacting with and blur out the rest. Their experience is different: By clicking this, the user expects to be able to submit feedback.
Instead, all they get is a darker screen, which could be a hardware problem running out of battery? They have no information on which to base their next move. In any of these cases, your AJAX solution will be neither usable nor accessible if the section that is replaced is far removed from the button that fires the AJAX request. You have two workarounds. The most obvious one is to keep the elements close together. If that is not possible, the other workaround is to change the content of the element that fires the AJAX request once the user clicks on it.
This indicates to the end user what is going on. As an added assistance, you can shift the keyboard focus to the target element when the AJAX request has been processed. Be aware, though, that this could confuse some users; being jumped around the screen without meaning to can be scary.
Pretty, smooth-transitioning solutions look good to the rest of us, but they can be a total nightmare for users with learning disabilities. Putting all of this together, take a look at this more accessible example. It adds a span to the link to show the state of the AJAX request, it highlights the content when it has finished loading, and then it shifts the focus to the new element. Here is the final code.
Free Основы Телевидения И Видеотехники Программа Методические Указания И Контрольные Задания 2005
Wavelets, Signals, Fractals NET 2. An Introduction to Contemporary Mathematics 3rd edition Problems and Solutions 1st edition The Art of Distributed System Design Plug-ins for J2EE Development Cluster and Grid Computing
35 Sitepiont Ebooks collection[all 35 books]
Oh no! Some styles failed to load. 😵