tailieunhanh - DHTML Utopia Modern Web Design Using JavaScript & DOM- P10

DHTML Utopia Modern Web Design Using JavaScript & DOM- P10:In a single decade, the Web has evolved from a simple method of delivering technical documents to an essential part of daily life, making and breaking relationships and fortunes along the way. “Looking something up on the Internet,” by which is almost always meant the Web, is now within reach of almost anyone living in a first-world country, and the idea of conducting conversations and business (and probably orchestras) in your Web browser is no longer foreign, but part of life | Chapter 6 Forms and Validation ing country names. Some have worked around the problem of locating particular countries in these long lists by putting the more frequently-selected countries at the top 13 but this is hardly an ideal solution. It is possible to press the key that corresponds with the initial letter of an entry in the list in order to jump to that entry repeatedly hitting that key will move between list entries that begin with that letter. This suggests an improvement perhaps instead of keypresses triggering initial-letter searches only they should accumulate into a string which is matched as a whole. While typing k i n in a standard drop-down will result in a jump to the first list entry beginning with k then the first beginning with i then the first beginning with n this could be changed so that those keypresses jump the selection to the first entry containing the string kin. That would probably be the United Kingdom or the Kingdom of Tonga in the countries example. Functionality very similar to this is actually already present in both Safari and Firefox. Both of those browsers let you type a series of letters to match the start of an entry in a drop-down list. This example takes this feature a step further by searching for the string anywhere in the list item. And it works in Internet Explorer to boot Unfortunately Safari does not support handling keyboard events on drop-down lists with JavaScript. As a result the enhancement we will undertake in this section will not apply to that browser. A number of further enhancements also suggest themselves the current accumulated string should be displayed somewhere so that the user can see what they ve entered similar to Firefox s type-ahead find feature. It should also be possible as with type-ahead find to press Backspace to remove the most recently-added letter from the accumulated string. Finally after a period without typing the accumulated string should be reset to blank to allow typing from scratch. .