Group items tagged

When possible, avoid using "link to" or "click this image" or similar wording in the alt attribute. Links are identified as links by screen readers and should be visually apparent to sighted users.

Decorative images do not present important content, are used for layout or non-informative purposes, and do not appear within a link. In almost all cases, spacer and decorative images should have null alt text (alt="").

Option C (alt="") would be most appropriate in this case because the image does not convey relevant or important content.

Form image buttons must have an alt attribute that describes the function of the button. Image buttons are often used to provide a more visually appealing or a smaller version of the standard form buttons. The alternative text should describe what the button will do when selected, such as "Search", "Submit", "Register", "Place your order", etc. For instance, <input type="image" alt="Submit Search"> might be appropriate for an image button on a site search form.

In many cases, images may be given an empty or null alt attribute (e.g., alt="").

Option B is the best choice - it clearly provides the content that is being presented by the image - that the link is to a PDF file.

Alt text of a functional image (e.g., an image within a link) should describe the function as well as the content.

First, choose the appropriate type attribute and element tag for your form controls. WebKit supports a variety of form control types including passwords, numeric and telephone fields, date, time, and select menus. Choosing the most relevant type attribute allows WebKit to present the most appropriate interface to handle user input.

Semantic HTML will give usability benefits to many users, help to future-proof your work, potentially boost your search engine results, and help people with disabilities use your site.

e chose not to try and replicate the entire Icelandair website, but rather to cleave from it four or five of its most crucial elements.

This page contains the only form on the mobile site. In general, forms should be avoided because form input via a mobile device can be a tricky endeavor. However, there are certain coding practices that can simplify form input. For example, if your form field should only accept numeric input, then you should make use of the -wap-input-format property of WAP CSS. The Apple iPhone will automatically set the input to numeric if the name of the input element is set to certain values - phone or zip for example.

Mobile users only need to be shown news items that have some inherent urgency.

Much like your desktop browser recognizes a mailto: link as an email address, mobile devices recognize tel: links and phone numbers.

Do not assume that just because the UA string is not in your enumerated list of “Accepted strings”, it is not possible to view the site.

This is where you build in progressive enhancements to the website experience.

WURFL is an open source list of known phones and their capabilities. This can be put into a database and when a mobile device visits the your site you can sniff the UA, look-up the capabilities of that device (including screen-dimensions, default browser, etc) and serve them the best possible experience.

The RDF vocabulary is a standard across many mobile devices. Vendors that use this approach allow mobile sites to keep up-to-date with any new devices, without having to keep their own database of device types.

ou can find more details about standards support in Opera Mini/Mobile 4 here: Designing with Opera Mini 4 in mind JavaScript support in Opera Mini 4

There are a few basic coding items to avoid in the mobile web space. Chief among these, at least for now (now being 10/2007), is client-side scripting.

While it's tempting to try and port that elegant bit of AJAX from your conventional web to your mobile web, you will only create headaches for yourself.

ome browsers do support various levels of JavaScript, but as a developer you should not expect it to work across all devices.

retty heavy processor hog, so continuous scripting can drain a battery fast

mobile browser support for stylesheets varies greatly.

keep things simple.

most mobile devices default to their own font sizes and families regardless of styling. Thus, when working on the Siminn project we made no attempt to influence font size or family. In cases where we wanted a larger font, we simply relied on the generic XHTML heading elements.

he inclusion of font-size=smaller in the body tag worked as a kind of global reset for font sizes in every device we tested. With this little bit of code we were able to sufficiently reduce the default font size and thus more faithfully reproduce the design that we had been tasked with coding.

XHTML-MP - the mobile web subset of XHTML - is fully supported on most modern devices.

You can't read 2 books and several articles about mobile web development and cover everything. Much of the effort is trial and error. When starting out, emulators are a good way to get a rough idea of how the site will work. It gives you some feel for the navigation, architecture and flow of the site, but the look and feel varies from the emulator to the real device. The best thing you can do is get a few real phones to test on. I'm sure between yourself, co-workers and a few friends, you can manage to test your site on a good cross-section of the phones out there. Finally, there is some help. The W3C mobile web initiative does have a checklist to see how well your site is doing and so does dev.mobi - if you take heed of these two lists, your site should give a quality experience to most customers.