February 17, 2000 - Universal Cookie Functions | WebReference

February 17, 2000 - Universal Cookie Functions

Yehuda Shiran February 17, 2000
Universal Cookie Functions
Tips: February 2000

Yehuda Shiran, Ph.D.
Doc JavaScript

In this tip we'll show you several universal functions for cookie manipulation. For your convenience, the functions are documented in the script body. Simply copy the entire script and paste it in the <HEAD>...</HEAD> portion of your HTML document.

<SCRIPT LANGUAGE="JavaScript">
<!--
// name - name of the cookie
// value - value of the cookie
// [expires] - expiration date of the cookie (defaults to end of current session)
// [path] - path for which the cookie is valid (defaults to path of calling document)
// [domain] - domain for which the cookie is valid (defaults to domain of calling document)
// [secure] - Boolean value indicating if the cookie transmission requires a secure transmission
// * an argument defaults when it is assigned null as a placeholder
// * a null placeholder is not required for trailing omitted arguments
function setCookie(name, value, expires, path, domain, secure) {
  var curCookie = name + "=" + escape(value) +
      ((expires) ? "; expires=" + expires.toGMTString() : "") +
      ((path) ? "; path=" + path : "") +
      ((domain) ? "; domain=" + domain : "") +
      ((secure) ? "; secure" : "");
  document.cookie = curCookie;
}
// name - name of the desired cookie
// * return string containing value of specified cookie or null if cookie does not exist
function getCookie(name) {
  var dc = document.cookie;
  var prefix = name + "=";
  var begin = dc.indexOf("; " + prefix);
  if (begin == -1) {
    begin = dc.indexOf(prefix);
    if (begin != 0) return null;
  } else
    begin += 2;
  var end = document.cookie.indexOf(";", begin);
  if (end == -1)
    end = dc.length;
  return unescape(dc.substring(begin + prefix.length, end));
}
// name - name of the cookie
// [path] - path of the cookie (must be same as path used to create cookie)
// [domain] - domain of the cookie (must be same as domain used to create cookie)
// * path and domain default if assigned null or omitted if no explicit argument proceeds
function deleteCookie(name, path, domain) {
  if (getCookie(name)) {
    document.cookie = name + "=" + 
    ((path) ? "; path=" + path : "") +
    ((domain) ? "; domain=" + domain : "") +
    "; expires=Thu, 01-Jan-70 00:00:01 GMT";
  }
}
// date - any instance of the Date object
// * hand all instances of the Date object to this function for "repairs"
function fixDate(date) {
  var base = new Date(0);
  var skew = base.getTime();
  if (skew > 0)
    date.setTime(date.getTime() - skew);
}
// -->
</SCRIPT>
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