On
the last page,
we learned how to cram lots of information into one cookie.
Another way to
do this is with multiple cookies.
Saving
multiple cookies is
very straightforward. We've learned that every cookie
has a name. In the
last example, we named the cookie
my_happy_cookie, and did
something like
this:
var the_cookie = "my_happy_cookie=happiness_and_joy";
document.cookie = the_cookie;
To save multiple cookies,
just
give each cookie a different name. If you're adding a new cookie,
setting
document.cookie doesn't delete cookies that are already
there. So
if we do this:
var the_cookie = "my_happy_cookie=happiness_and_joy";
document.cookie = the_cookie;
var another_cookie= "my_other_cookie=more_joy_more_happiness";
document.cookie = another_cookie;
You'll now have access
to
both cookies. It's sort of weird, so make sure you understand
what's going
on.
Let's assume you executed the last block of code
and you want
to access my_happy_cookie. If you look
at
document.cookie, you'll
see
this:
my_happy_cookie=happiness_and_joy;
my_other_cookie=more_joy_more_happiness;
If you
don't
believe me, just look
at your cookie.
function WM_readCookie(name) {
if (document.cookie == '') {
// there's no cookie, so go no further
return false;
} else {
// there is a cookie
var firstChar, lastChar;
var theBigCookie = document.cookie;
firstChar = theBigCookie.indexOf(name);
// find the start of 'name'
if(firstChar != -1) {
// if you found the cookie
firstChar += name.length + 1;
// skip 'name' and '='
lastChar = theBigCookie.indexOf(';', firstChar);
// Find the end of the value string (i.e. the next ';').
if(lastChar == -1) lastChar = theBigCookie.length;
return unescape(theBigCookie.substring(firstChar, lastChar));
} else {
// If there was no cookie of that name, return false.
return false;
}
}
}
// WM_readCookie
Since this is very well
commented,
I'll just let you take a look at it and figure out what's
happening on your
own (c'mon, you know everything you need to know to make
sense of
this).
Once you've parsed that information, let's leave
our
"setting and reading basic cookies" discussion and look at some of
the
cooler things you can do with cookies.
next page»
