providing resilient xpaths for external adaptation engines
Approaches to Web application adaptation can be classified based on whether the application is aware of the adaptation or not. In the latter case, adaptation is referred to as external. External adaptation requires the use of addressing patterns that locate the target portion/data on the application pages to be adapted. Unfortunately, changes on the application normally also require updates to the addressing patterns. This raises pattern robustness as a main concern. This papers focuses on the (semi) automatic generation of change-resilience XPath patterns. Two different categories of changes are addressed, i.e. in space (e.g., different personalizations of a page) and in time (e.g., site upgrades), by exploiting two different techniques: induction and simulated annealing. These techniques permit to obtain XPath patterns "resilient-enough" to a "controlled set of page designs" . SiSy , a tool that assists the user in obtaining resilient XPath expressions, was born out of this approach. The approach is tested for two websites (www.yahoo.com and www.elmundo.es), identifying 23 updates to which XPath expressions were resilient to 62\% of the undertaken changes.
xpath external adaptation change resilience evolution