OASIS has announced the approval of the Web Services for Remote Portlets Specification Version 1.0 as an OASIS Standard, reflecting the collaborative effort of some twenty-five (25) OASIS member companies. WSRP defines the interface and semantics for a web service standard "that allows for the plug-and-play of content sources (e.g., portlets) with portals and other aggregating web applications. It thereby standardizes the consumption of Web services in portal front ends and the way in which content providers write Web services for portals. Scenarios that motivate WSRP/WSIA functionality include: (1) Portal servers providing portlets as presentation-oriented web services that can be used by aggregation engines; (2) Portal servers consuming presentation-oriented web services provided by portal or nonportal content providers and integrating them into a portal framework. The the description also applies generally to non-portal environments. WSRP allows content to be hosted in the environment most suitable for its execution while still being easily accessed by content aggregators. The standard enables content producers to maintain control over the code that formats the presentation of their content. By reducing the cost for aggregators to access their content, WSRP increases the rate at which content sources may be easily integrated into pages for end-users."

Bibliographic Information

Web Services for Remote Portlets Specification. Approved OASIS Standard. August 2003. Edited by Alan Kropp (Vignette Corporation), Carsten Leue (IBM Corporation), and Rich Thompson (IBM Corporation). Contributors include: Chris Braun (Novell), Jeff Broberg (Novell), Mark Cassidy (Netegrity), Michael Freedman (Oracle Corporation), Timothy N. Jones (CrossWeave), Thomas Schaeck (IBM Corporation), and Gil Tayar (WebCollage). Document identifier: 'wsrp-specification-1.0'. 86 pages.

The WSRP version 1.0 WSDL documents provide details for of each of the operations and XML messages exchanged by compliant services.

• Interfaces. This WSDL defines the portType definitions for this specification. These definitions form the urn:oasis:names:tc:wsrp:v1:intf namespace.
• Bindings. This WSDL provides the standard binding definitions for this specification. These definitions form the urn:oasis:names:tc:wsrp:v1:bind namespace.
• Schema. The XML Schema defines the type, message and fault definitions for this specification. These definitions form the urn:oasis:names:tc:wsrp:v1:types namespace.

WSRP Specification Abstract

"Integration of remote content and application logic into an End-User presentation has been a task requiring significant custom programming effort. Typically, vendors of aggregating applications, such as a portal, write special adapters for applications and content providers to 25 accommodate the variety of different interfaces and protocols those providers use. The goal of this specification is to enable an application designer or administrator to pick from a rich choice of compliant remote content and application providers, and integrate them with just a few mouse clicks and no programming effort."

This specification is a joint effort of two OASIS technical committees. Web Services for Interactive Applications (WSIA) and Web Services for Remote Portals (WSRP) aim to simplify the integration effort through a standard set of web service interfaces allowing integrating applications to quickly exploit new web services as they become available. The joint authoring of these interfaces by WSRP and WSIA allows maximum reuse of presentation-oriented, 35 interactive web services while allowing the consuming applications to access a much richer set of standardized web services.

This joint standard layers on top of the existing web services stack, utilizing existing web services standards and will leverage emerging web service standards (such as security) as they become available. The interfaces are defined using the Web Services Description Language (WSDL)."

WSRP Overview

"The Web Services for Remote Portlets (WSRP) specification defines the Web services interfaces and semantics for interactive, presentation-oriented content services. This allows the content consumers, such as portals, to access conformant services without requiring service-specific code."

WSRP benefits content aggregators by eliminating the need for content aggregators to choose between locally hosting a content source or writing code specific to each remote content source. Rather, WSRP allows content to be hosted in the environment most sensible for its execution while still being easily accessed by content aggregators.

WSRP enables content producers to maintain control over the code that formats the presentation of their content. This reduces the distribution of updates problem frequently faced today. In addition, by reducing the cost for content aggregators to access their content, WSRP increases the rate at which content sources may be easily integrated into pages for end-users.

WSRP was submitted to the OASIS membership on 1-August-2003 for consideration as an OASIS Standard. As of July 2003, at least six vendors had reported on implementations underway and on plans to participate in the interoperability testing the OASIS WSRP TC is supporting. The OASIS WSRP TC is beginning work on follow-on versions which will add more advanced features (e.g., cross-portlet coordination).

WSRP seeks to leverage Web services standards as they are widely available in Web stacks. WSRP v1 uses WSDL to describe the interfaces, requires at least SOAP bindings be provided to all conformant services, defines the passed message structures using XML Schema and uses XML to carry the messages between the services and their clients. Future versions are exploring emerging standards in the areas of attachments and security, among others.

Since WSRP was developed in parallel with the effort by the Java community to standardize a portlet API, care has been taken to align these two new standards with each other. In addition, care has been taken to ensure WSRP can be easily supported on a .NET platform. One example of how these efforts relate to developers is that vendors have indicated that portlets developed to the new Java Portlet API will not need to be aware that they may be accessed remotely using the WSRP protocol, but rather it is a feature of the hosting container to provide such access as if it had occurred locally..." [adapted from the TC FAQ document]

From the Announcement

"WSRP defines how Web services plug into portals," explained Delphi President, Thomas Koulopoulos. "Once a WSRP service is published to a public directory, portal administrators are able to locate and dynamically integrate it with just a few mouse clicks. WSRP is a critical standard enabling distributed portals to share portlets as visual, user-facing Web services for integration with other portals."

WSRP eliminates the need for content aggregators to choose between locally hosting a content source or writing code specific to each remote content source. Instead, WSRP allows content to be hosted in the environment most suitable for its execution while still being easily accessed by content aggregators. The standard enables content producers to maintain control over the code that formats the presentation of their content. By reducing the cost for aggregators to access their content, WSRP increases the rate at which content sources may be easily integrated into pages for end-users.

"The OASIS WSRP Technical Committee was founded in early 2002 with the vision of providing a single interface standard for all interactive, presentation-oriented Web services. WSRP v1.0 succeeds in providing this platform neutral definition of an interface," said Rich Thompson of IBM, chair of the OASIS WSRP Technical Committee. "Early vendor support for WSRP -- we've tracked eight implementations to date -- clearly demonstrates the need for this standardized means of accessing remote content."

"WSRP builds on foundational work from the Worldwide Web Consortium (W3C)," said Patrick Gannon, president and CEO of OASIS. "WSRP uses WSDL to describe interfaces, and requires SOAP bindings for all conformant services. WSRP is an excellent example of how an open, standards-based approach will enable end-user interactive web services to be deployed in a lower cost, faster-to-implement, plug-and-play environment."

WSRP allows remote portlet Web services to be implemented in a variety of ways, including Java/J2EE and Microsoft's .NET platform.

WSRP is the result of a collaboration of 25 OASIS member companies including BEA Systems, Citrix Systems, Factiva, IBM, Microsoft, Novell, Oracle, Plumtree Software, Reed Elsevier, SAP, Sun Microsystems, TIBCO, and Vignette. It joins a growing portfolio of OASIS Standards and specifications for Web services including Universal Description, Discovery, and Integration of Web Services (UDDI), Web Services Business Process Language (WSBPEL), Web Services for Distributed Management (WSDM), Web Services for Reliable Messaging (WSRM), WS-Security, and others. OASIS currently has more than 60 active technical committees.

About the OASIS WSRP TC

The Web Services for Remote Portlets Technical Committee was chartered to:

• Create an XML and web services standard that will allow for the "plug-n-play" of portals, other intermediary web applications that aggregate content, and applications from disparate sources. These so-called remote portlet web services will be designed to enable businesses to provide content or applications in a form that does not require any manual content or application-specific adaptation by consuming applications.
• harmonize WSRP as far as practical with existing web application programming models (e.g. Portals/Portlets, Macromedia Flash, ...), with the work of the Java Community Process (e.g. JSR 168 Portlet Specification), with the programming model of .NET, with the work of the W3C (e.g. XForms, DOM, XML Events, XPath, XLink, XML Component API task force), emerging web services standards (e.g. SOAP, WSDL, WSBPEL) and with the work of other appropriate business information bodies.
• Promote WSRP to the status of an international standard for the conduct of XML and Web Services based web application development, deployment and management.