Pankaj Kumar's Weblog

Hoping to save some time, I decided to use the JavaScript Cookie class provided in the otherwise excellent book JavaScript: The Definitive Guide, 5th Edition. However, my program was not working as intended -- the cookies that were supposed to last the whole session were getting reset at every new page. After an hour of alert() and FireBug assisted debugging finally helped me to track down the problem: the Cookie class was not behaving properly. Just submitted an errata to O'reilly's. Here is the submission:

document.cookie value on FireFox includes a blank space after ';'. As a result, the code to extract a particular cookie value doesn't work:

    var cookies = allcookies.split(';');
    var cookie = null;
    for(var i = 0; i < cookies.length; i++) {
        // Does this cookie string begin with the name we want?
        if (cookies[i].substring(0, name.length+1) == (name + "=")) {
            cookie = cookies[i];
            break;
        }
    }

This can be easily fixed by first replacing all blanks with zero length strings, as in:

    var cookies = allcookies.replace(" ", "").split(';');

My program is happy now.