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ASP Application Object

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A group of ASP files that work together to perform some purpose is called an application.

Application Object

An application on the Web may consist of several ASP files that work together to perform some purpose. The Application object is used to tie these files together.

The Application object is used to store and access variables from any page, just like the Session object. The difference is that ALL users share ONE Application object (with Sessions there is ONE Session object for EACH user).

The Application object holds information that will be used by many pages in the application (like database connection information). The information can be accessed from any page. The information can also be changed in one place, and the changes will automatically be reflected on all pages.

Store and Retrieve Application Variables

Application variables can be accessed and changed by any page in an application.

You can create Application variables in "Global.asa" like this:

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

Sub Application_OnStart
application("vartime")=""
application("users")=1
End Sub

</script>

In the example above we have created two Application variables: "vartime" and "users".

You can access the value of an Application variable like this:

There are
<%
Response.Write(Application("users"))
%>
active connections.

Loop Through the Contents Collection

The Contents collection contains all application variables. You can loop through the Contents collection, to see what's stored in it:

<%
dim i
For Each i in Application.Contents
  Response.Write(i & "<br>")
Next
%>

If you do not know the number of items in the Contents collection, you can use the Count property:

<%
dim i
dim j
j=Application.Contents.Count
For i=1 to j
  Response.Write(Application.Contents(i) & "<br>")
Next
%>

Loop Through the StaticObjects Collection

You can loop through the StaticObjects collection, to see the values of all objects stored in the Application object:

<%
dim i
For Each i in Application.StaticObjects
  Response.Write(i & "<br>")
Next
%>

Lock and Unlock

You can lock an application with the "Lock" method. When an application is locked, the users cannot change the Application variables (other than the one currently accessing it). You can unlock an application with the "Unlock" method. This method removes the lock from the Application variable:

<%
Application.Lock
'do some application object operations
Application.Unlock
%>

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