The Session.OnEnd() Event

Introduction

The Session.OnEnd event applies to the Session object. In ASP there is a session for visitors who has their cookies turned on. If they do not have cookies turned on, these events won't run. The OnEnd event is called whenever a session ends or times out. See the timeout property of the session object to find out more about timeouts. Usually you load something in the OnStart event and you unload it on the OnEnd event.  The OnEnd event is useful for clearing up any resources when the user leaves. In the following OnStart event we have an application variable called "CurrentUserCounts" and we add 1 to it, every time another user visits the site. In this OnEnd event we minus 1 from an application variable called "CurrentUserCounts", because the user has left the website.

Example (global.asa)

<script language="vbscript" runat="server">

Sub Session_OnStart

       Application("CurrentUserCounts") = Application("CurrentUserCounts") + 1

       session("memberId") = trim(request.cookies("member")("memberId"))

End Sub

Sub Session_OnEnd

       Application("CurrentUserCounts") = Application("CurrentUserCounts") - 1

End Sub

</script>

In this example, we use the application variable called "CurrentUserCounts" in our front page of the website to display how many users are online at the moment. The variable "CurrentUserCounts" is written out using the write method of the ASP response object.

Example (session_object_event_onend_example.asp)

<%

       response.write Application ("CurrentUserCounts")

%>

Output

 The above screenshot shows two open browsers. The first one shows only one user online. This browser was opened first. After that another browser has been opened and the number of users has increased by one, therefore the second browser shows now two users.