Static Validation of Dynamically Generated HTML.pdf

Static Validation of Dynamically Generated HTML Claus Brabrand, Anders Møller, and Michael I. Schwartzbach BRICS Department of Computer Science University of Aarhus, Denmark {brabrand,amoeller,mis}@brics.dk ABSTRACT our technique can be generalized to more powerful grammatical We describe a static analysis of bigwig programs that effi- descriptions. ciently decides if all dynamically computed XHTML documents Outline presented to the client will validate according to the official DTD. We employ two data-flow analyses to construct a graph summariz- First, in Section 2, we give a brief introduction to dynamically gen- ing the possible documents. This graph is subsequently analyzed erating XHTML documents in the bigwiglanguage. Section 3 to determine validity of those documents. By evaluating the tech- formally defines the notion of summary graphs. In Sections 4 and 5, nique on a number of realistic benchmarks, we demonstrate that it the two parts of the data-flow analysis are specified. Then, in Sec- is sufficiently fast and precise to be practically useful. tion 6, a notion of abstract DTDs is defined and used for specifying XHTML 1.0. Section 7 describes the algorithm for validating sum- mary graphs with respect to abstract DTDs. In Section 8 we eval- 1. INTRODUCTION