Cookies are small pieces of data stored on users' devices that can be used to track their browsing habits, preferences, and behavior. There are several types of cookies, including:
To set cookies in your web application, you'll need to create a JavaScript file (usually called a 'cookie.js' or similar) and include the following code:
function setCookie(key, value, expires) {
var date = new Date();
if (expires == "days") {
date.setDate(date.getDate() + expires);
} else if (expires == "hours") {
date.setHours(expires);
}
// Set the cookie
document.cookie = key + "=" + escape(value) + ";expires=" + expires;
}
function getCookie(key) {
var value = "";
var cookies = document.cookie.split('; ');
for (var i in cookies) {
if (cookies[i].indexOf(key) == 0)
return cookies[i].substr(key.length + 1);
}
return false;
}
When a user navigates to your web application, their browser sends an HTTP request. Cookies are sent along with the request, but they're not stored on the server-side by default. However, some cookies can be included in the response headers as well.
To include a cookie in the response header, you'll need to set an HTTP header (usually called 'Set-Cookie') and include the desired value for the cookie name and value. For example:
responseHeader = "Set-Cookie: cookie_name=cookie_value; httpOnly=True"
Here are a few best practices and tricks to keep in mind when working with cookies: