Portal Request Cycle 
The request cycle starts when the dispatcher receives an HTTP request and ends when the response is sent back to the browser. The dispatcher selects the portal connection according to the information encoded in the URL. The default connection performs the following steps:
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1. User authentication
Authenticates the user attached to the request
2. Use JNDI to get the portal object that has to be rendered
The name of the portal object to be started is provided by the prtroot URL parameter
3. Create the Portal Object Model (POM)
Create the request's POM, which represents the structure of all components in the portals that participate in event handling and content creation within this request. During creation, the PRT notifies the participating elements to create their sub-structures in the POM and notifies them about their state
4. Handle request event
Raise any event defined by using an appropriately generated URL
5. Start the content collection phase. The process steps are:
a. Before content phase
The before content event is sent to all the nodes in the POM. All nodes involved in the POM can perform special actions before the actual content phase start
b. Content phase
Retrieve the content of all the nodes present in the POM
c. After content phase
An after content event is sent to all nodes in the POM
Node
When building the POM, the PRT constructs a tree of special objects called Node. The Node semantics are defined in the INode interface. It offers methods that can:
· Construct and traverse the tree
· Send and receive events
· Store and retrieve data
· Access the portal component instance attached to it. Every portal component involved in the process of the request is attached to a Node.
Node and Component Relations
A simple POM with three Nodes. The root node called the portal node, a Node without any component attached to it and a Node with its component.
See also: