SXPath: a Spatial Extension of XPath

We report on a recently introduced extension of XPath, called SXPath, which is a new framework for querying Web documents by considering tree structures as well as spatial relationships between laid out elements. The underlying rationale is that frequently the rendering of tree structures is very involved and undergoing more frequent updates than the resulting layout structure. In this paper, we present the syntax and the semantics of the language that are based on a combination of a spatial algebra with formal descriptions of XPath navigation. Such language is intuitive and general enough to capture most frequent extraction patterns. Moreover, we show that the language maintains polynomial time combined complexity. Practical experiments demonstrate the usability of SXPath. This work is a short version of [11].