Portlet syndication: Raising variability concerns

A Portlet is a multistep, user-facing application delivered through a Web application (e.g., a portal). OASIS approved standard, WSRP, is an attempt to standardize the interface between the provider and the consumer of the Portlet. This initiative promotes Portlet interoperability, componentware practices, and the existence of a Portlet market. This work argues that the diversity of the settings where a Portlet might be syndicated recommends that Portlets be instrumented for variability, and this, in turn, demands a product-line approach. This work introduces a new source of variability, the “interaction lifecycle”, a description of the visible flow of a Portlet, and shows how this feature can be adapted to cater to the idiosyncrasies of the hosting application. Distinct variants are identified that permit the consumer to customize the presentation, content, and links of the Portlet markup in a controlled way. The use of product-line techniques allow the consumer to cope with this variability in a cost-effective manner. The article ends by illustrating how the extensible capabilities of WSRP are used to accomodate this process.