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Articles | Automating NEW! |
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I got the idea for this facility from A
Beginner's Guide to JavaScript
Rather than amend which items are new on an infrequent
basis, why not automate it with a JavaScript function called check_if_new():
<script language="JavaScript"><!--
function y2k(number) { return (number < 1000) ? number +
1900 : number; }
function check_if_new(then) {
var today = new Date();
var difference = Date.UTC(y2k(today.getYear()),
today.getMonth(),today.getDate(),0,0,0)
- Date.UTC(y2k(then.getYear()),then.getMonth(),
then.getDate(),0,0,0);
var days_difference = difference/1000/60/60/24;
if (days_difference < 14)
return '<em>NEW!<\/em>';
else return '';
}
date = new Date(1997,2,20);
document.write(check_if_new(date));
//--></script>
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Date.UTC() (Universal Coordinated Time)
returns the number of milliseconds in a Date object since January 1, 1970,
00:00:00.
For example Date.UTC(1997,0,1), i.e. 1st
January 1997, will always return 852076800000.
By subtracting the Universal Coordinated Time of one
date from another we can find the difference in milliseconds between two dates.
By dividing this difference by 1000 milliseconds and by
60 seconds and by 60 minutes and then by 24 hours, we can find the difference in
days between two dates.
By comparing this difference in days with a static
number we can tell whether the date falls within a predetermined range, e.g. 14
days, and if so output the text NEW!.
Alternatively, an image can be output:
<script language="JavaScript"><!--
function y2k(number) { return (number < 1000) ? number +
1900 : number; }
function check_if_new(then) {
var today = new Date();
var difference = Date.UTC(y2k(today.getYear()),
today.getMonth(),today.getDate(),0,0,0)
- Date.UTC(y2k(then.getYear()),then.getMonth(),
then.getDate(),0,0,0);
var days_difference = difference/1000/60/60/24;
if (days_difference < 14)
return '<img src="new.gif">';
else return '';
}
date = new Date(1997,2,20);
document.write(check_if_new(date));
//--></script>
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Also read the article
Chocolate
Chip Cookies + Automating NEW!
Articles | Automating NEW! |
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