March 09, 2011, 11:25 AM — The changes and enhancements to the form tags are some of the most extensive amendments to the HTML5 standard, offering a wide variety of options that once required add-on libraries and a fair amount of tweaking. All of the hard work that went into building self-checking widgets and the libraries that ensure the data is of the correct format is now being poured into the browser itself. The libraries won't be necessary -- in theory -- because the work will be done seamlessly by all browsers that follow the standard. In practice, we'll probably continue to use small libraries that smooth over slight inconsistencies.
The new HTML specifications include input types that offer a number of new options for requesting just the right amount of data -- say, a form element that requests the time in different levels of granularity, such as month, week, or minute. Other new input types insist that the user type in only valid URLs or email addresses. All of these input fields will be tested to ensure that the text in them is valid and that the user's progress toward satisfying the data integrity police will be tracked by a series of events. There are even hooks for a value sanitization algorithm that checks the information and perhaps cleans it up with some AJAX.
Compliance with these options is gradually appearing in the browsers. At the time of this writing, for instance, Chrome lets you pin the min and max for some dates, but you can't install a value sanitization function. The minimum and maximum values are, of course, the simplest controls to create. It's much harder to offer the deeper hooks.