Configuration objects
The following objects are used by the portlet to retrieve and store data, depending on how the data is used:
PortletConfig
The PortletConfig provides the non-concrete portlet with its initial configuration. The configuration holds information about the portlet class. This information is valid for every concrete portlet derived from the portlet.
A portlet's configuration is initially read from its servlet deployment descriptor. This information is set by the portlet developer. The configuration is read-only and cannot be changed by the portlet.
The PortletConfig is passed to the portlet in the init() method of the abstract Portlet and is used to access portlet-specific configuration parameters using getInitParameters(). PortletConfig parameters are name/value pairs available for the complete life cycle of the non-concrete portlet. Non-concrete portlet's parameters are defined by the <init-param> tag in the servlet deployment descriptor.
PortletSettings
The PortletSettings object provides the concrete portlet with its dynamic configuration. The configuration holds information about the concrete portlet. This information is valid for every instance of the concrete portlet.
A concrete portlet's configuration is initially read from the portlet deployment descriptor. The configuration is read-only and can be written by the portlet only when the portlet is in configure mode. This information is normally maintained by the portal administrator and may be changed while the portal server is running. The portlet can get, set, and remove attributes during one request. To commit the changes, the store() method has to be called.
The PortletSettings object can be accessed with the getPortletSettings() method, available from the PortletRequest. Often, it is used to access portlet-specific configuration parameters using getAttribute(). Attributes are name/value pairs available for the complete life cycle of a concrete portlet. Concrete portlet attributes are defined by the <config-param> tag in the portlet deployment descriptor.
Changes to portlet settings first occur when any request enters the portlet container. The portlet might not get the information in cases when the server shuts down. However, the information is securely saved in the backend system and can be retrieved in a later session.
PortletApplicationSettings
The PortletApplicationSettings object provides the concrete portlet application with its dynamic configuration.
The configuration holds information about the portlet application that is shared across all concrete portlets included in the application.
A concrete portlet application's configuration is initially read from the portlet deployment descriptor. The configuration is read only and can be written by the portlet only when the portlet is in configure mode.
This information is normally maintained by the portal administrator and may be changed while the portal server is running. A portlet in the application can get, set, and remove attributes during one request. To commit the changes, the store() method has to be called.
The PortletApplicationSettings can be accessed with the getApplicationSettings() method, available from the PortletSettings object. It is used to access portlet-specific configuration parameters using getAttribute(). Attributes are name/value pairs available for the complete life cycle of a concrete portlet application. Concrete portlet application attributes are defined by the <context-param> tag in the portlet deployment descriptor.
Changes to portlet settings first occur when any request enters the portlet container.
The portlet might not get the information in cases when the server shuts down. However, the information is securely saved in the backend system and can be retrieved in a later session.
PortletData
The PortletData holds data for the concrete portlet instance. For each occurrence on a page there is a concrete portlet instance. The PortletData contains persistent information about the concrete portlet instance while the PortletSession contains only the transient data of the user portlet instance.
There is one concrete portlet instance for each occurrence of a portlet on a page. A page can be owned by either a single user (personal page) or by a single group of users (group page). PortletData contains user-specific data on a personal page and group-specific data on a group page.
The PortletData object stores attributes as name/value pairs. The portlet can get, set, and remove attributes during one request. To commit the changes, the store() method has to be called. The data is read only and can be written by the portlet only when the portlet is in edit mode.
Related information
- Portlet development basics
- Using PortletSettings and PortletApplicationSettings to allow dynamic configuration information in concrete portlets
Parent topic:
IBM Portlet API