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Publish/subscribe message based communication


These communication methods are based on directed communication links that pass information from a source portlet to a target portlet.

The portlet programmer defines which information a portlet can send or receive in order to participate in the communication. At run time data is passed by an event broker component across communication links created by administrators or end users. When data is sent across a link, the target portlet is explicitly invoked to process the received information and can perform arbitrary updates as a side-effect. This is called the push model. Previously cached markup is discarded as a result of receiving an event.

Message based communication allows more programmatic and administrative control than shared state, but also creates more overhead. To coordinate many portlets and create a large number of connections, consider using shared state instead.


Parent: Portlet communication
Related:
Shared portlet state
Special purpose techniques for data exchange
Portlet events based communications
Cooperative portlets
Interoperability between events and cooperative portlets
Event broker
Portlet wires
Public render parameters
Known issues and restrictions with portlet communication


Communication with persistent wires

The following two communication techniques are based on persistent data links, also called portlet wires. The wires have to be configured in a separate step before the portlets can communicate:

Note that we can create communication links in both directions between JSR 286 portlets and JSR 168 portlets using the cooperative portlet API. Howeverthat API does not support communication links between IBM and JSR 168 portlets.


Communication with dynamic menus

The following two communication techniques are based on dynamically generated menus that allow portal users to select a target destination for displayed data at run time: