Client Side State Management : Cookies
When you go to a website and the website leaves a txt file/files on your computer that contains information for the website to use the next time you come to the site called Cookies.Cookies are used to identify a user, to store state information, user selection options and other details of the user and etc.
C# code to create a cookie.
//Create a cookie
HttpCookie trialCookie = new HttpCookie(“ABC”);
trialCookie.Value = txtLoginName.Text;
//To set expiration time of cookie to 20 minutes from now.
trialCookie.Expires = DateTime.Now + new TimeSpan(0,0,20,0);
//Add the cookie to users computer
The cookie can also save multiple values:
Response.Cookies[“cookie1”][“key1”].Value = “value1”;
To access the cookies
if (Request.Cookies[“ABC”] == null)
//The cookie is not available go on without it.
//Cookie is still there let’s read it.
string oldValue = Request.Cookies[“ABC”].Value;
- The user can disable cookies in browser.
- Most browsers support cookies of up to 4096( 4k) bytes. This limitation makes the cookies a way to store only small amount of data.Some new browsers supports up to 8k data
- Browsers have a limit on the amount of cookies a web site can save in the client.Most browsers allow only 20 cookies per site.
- We can not leave critical information in cookies, as they are places on client computer and information can be easily found.