Cookies

Javascript Cookies function

From : head first Javascript (ISBN:9789866840241)

 

function writeCookie(name, value, days) {

      // By default, there is no expiration so the cookie is temporary

      var expires = "";

      // Specifying a number of days makes the cookie persistent

      if (days) {

        var date = new Date();

        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));

        expires = "; expires=" + date.toGMTString();

      }

      // Set the cookie to the name, value, and expiration date

      document.cookie = name + "=" + value + expires + "; path=/";

    }

    function readCookie(name) {

      // Find the specified cookie and return its value

      var searchName = name + "=";

      var cookies = document.cookie.split(';');

      for(var i=0; i < cookies.length; i++) {

        var c = cookies[i];

        while (c.charAt(0) == ' ')

          c = c.substring(1, c.length);

        if (c.indexOf(searchName) == 0)

          return c.substring(searchName.length, c.length);

      }

      return null;

    }

    function eraseCookie(name) {

      // Erase the specified cookie

      writeCookie(name, "", -1);

    }