Oracle9iAS Portal Developer Kit
A Primer on PL/SQL Portlet Services

The Oracle9iAS Portal provides a rich set of services which can be used to create powerful PL/SQL portlets. As a developer, you can use these services instead of having to create an infrastructure for yourself. This article provides an overview of the major services available for database portlets.

DATABASE PROVIDER SERVICES

Providers are the interface between portlets and Oracle9iAS Portal. Database providers are implemented as PL/SQL stored procedures. They act as a proxy between Oracle9iAS Portal and portlets so that the Portal has a consistent interface for abstracting the implementation details and location of individual portlets.

Provider Registration

When you register a provider, you tell Oracle9iAS Portal about a set of portlets, how to access them, and properties to apply when calling them. Oracle9iAS Portal provides facilities for manually registering providers but you can also do so programmatically using the wwpro_api_provider_registry APIs.

Provider Implementation

The provider implementation methods are the actual interface which Oracle9iAS Portal calls to display portlets. These methods are available in the wwpro_api_provider package.

PL/SQL PORTLET SERVICES

The base installation of Oracle9iAS Portal provides a set of PL/SQL services (APIs) that is accessible to any PL/SQL portlet. These services are accessible to Java through wrapper calls.

End-User Personalization

You can provide customization options so that users can tailor a portlet's behavior to their preferences. These settings are saved for each individual. The Oracle9iAS Portal environment provides a unique identifier for each individual, a preference store automatically mapped by user, and access mechanisms for storing and retrieving personalization information.

By default, when you enable end-user personalization, the "Customize" link appears on the title bar of your portlet. Typically, this link leads to a form where users can choose settings for that portlet.

End-user personalization options are available through the wwpre_api package.

Security

PL/SQL portlets typically use Oracle9iAS Portal's security mechanism. They leave authentication to Oracle9iAS Portal and trust that the Portal will return the correct, validated user upon request.

Oracle9iAS Portal strictly controls access to information and applications. This is accomplished by assigning specific privileges to users and groups. Portal security services allow you to specify access control programmatically and check for the appropriate privileges at runtime.

Security services are available through the wwsec_api package.

Session Storage

Oracle9iAS Portal provides a convenient way to record and access an individual's information for their current session. Each Portal user has a unique identifier which maps directly to the Oracle9iAS Portal session storage tables in the database. This mechanism allows temporary, user-specific information to be accessed by portlets. When the user logs out, this information is removed from the database.

Session storage services are available through the wwsto_api package.

Session Context

Session context services return information about a user's session. The session context includes information about the portal visitor including username, current session ID, IP address, and language preference. It also includes supporting information such as the Portal schema currently being used.

Session context services are available through the wwctx_api package.

National Language Support (NLS)

Oracle9iAS Portal has a robust infrastructure for supporting multiple languages. Instead of having to hardcode strings into a portlet user interface, you can store portlet text in the database and poll the Oracle9iAS Portal language store for the correct strings based on the browser's language setting.

NLS services are available through the wwnls_api package.

Error Handling

Oracle9iAS Portal provides consistent ways to trap erroneous input and provide meaningful error messages. The portal has methods for managing the internal error stack. This stack keeps track of raised exceptions and information about those errors. Oracle9iAS Portal also has a set of APIs for presenting errors in a standardized way.

Error handling services are available through the wwerr_api package.

Event Logging

Oracle9iAS Portal can log actions performed on its objects. These logs are stored in the database and are available through standard SQL calls and reporting tools.

Event logging services are available through the wwlog_api packages.

Revision History:

- September 24, 2000. Version 1.0.5.