Scopes available in ATG

Nucleus gives a place to live for all its components. For managing their life span, it uses a variable named "scope" for all its components. As, it is a nucleus property, it is preceded by $ sign.

An application component can be set to one of the following scopes:

• Global: Component is shared among all users.
• Session: Separate instances of the component are provided to each user.
• Request: Separate instances of the component are provided to each active request.

Specifying component scopes

You specify a component’s scope by setting its $scope property to global, session, or request. For example, a NewPerson component might be set to session scope as follows:

$class=Person
$scope=session
name=Bill
age=28

Note: If a component’s $scope property is not explicitly set, it automatically has global scope.

A component’s properties should always point to objects whose scope is equal to or greater than its own. Thus, global-scope component properties should only point to objects that also have global scope; session-scope component properties should only point to objects that have global or session scope; while request-scope component properties can point to objects of any scope, including request.