A Semi-Automatic Methodology for Repairing FaultyWeb Sites

Resum L'increment de la complexitat dels sistemes Web ha donat lloc al desenvolupament de sofisticades metodologies formals per a verificar i corregir la informació i els programes a la Web. En general, comprovar si un sistema Web es comporta correctament en respecte a la intenció original del programador així com verificar la seua consistència no son tasques trivials. La prova d'açò es la quantitat d'estudis que existixen a la lliteratura al respecte d'estes comprovacions. A la tesis, abordem dos problemes interessants relacionats a la verificació de sistemes Web. En primer lloc, ampliem un marc previ de verificació Web, basat en reescritura parcial, afegint una tècnica per a la reparació de sistemes Web. Proposem una metodologia de reparació bàsica dotada amb distintes estratègies per optimitzar el nombre d'accions que deuen ser executades per reparar una web donada. A més, desenvolupem un millora del marc de verificació Web que està basada en interpretació abstracta i millora en gran mida la eficiència i la escalabilitat de la tècnica original. En segon lloc, formalizem un marc lògic de re-escritura per l'especificació i 'model-checking' de aplicacions Web dinàmiques. El nostre marc, mos permet simular la navegació d'un usuari i avaluar els scripts Web dins de la aplicació Web, així com verificar importants propietats com per eixample d'abastabilitat i consistència. Quan una propietat es refutada, es mostra un contra-eixample amb la traça errònea. Aquesta informació pot ser analitzada amb la finalitat de depurar l'aplicació Web que esta sent analitzada. Per aquest propòsit, formulem una nova tècnica d'slicing cap enrere sobre les traces donades. Aquesta tècnica consisteix en buscar cap enrere, sobre la traça d'execució, els símbols rellevants del terme (o estat) en el qual estem interessats a observar. Contents xviii Contents

Computer-Aided Design of User Interfaces V, 2007

The need for checking both usability and accessibility of Web sites is widely recognized, approved and recommended by several official organizations. What should really be more recognized or addressed is an equal need for repairing the usability and accessibility defects that have been detected. Within the DESTINE suite, we developed a tool allowing to repair the HTML source code of a page with user interaction. Thanks to an improved version of the Guideline Definition Language (GDL), the accessibility guidelines are not hard-coded, so that our tool can deal with any existing or future standards.

2001

Abstract The growth of the World Wide Web and the accelerated development of web sites and associated web technologies has resulted in a variety of maintenance problems. The maintenance problems associated with web sites and the WWW are examined. It is argued that currently web sites and the WWW lack both data abstractions and structures that could facilitate maintenance. A system to analyse existing web sites and extract duplicated content and style is described here.

2009

WWV'09 provided a common forum for researchers from the communities of Rule-based programming, Automated Software Engineering, and Web-oriented research, in order to facilitate the cross-fertilization and the advancement of hybrid methods that combine the three areas. The Program Committee of WWV'09 collected three reviews for each paper and held an electronic discussion during April 2009 which has led to the selection of 10 regular papers. In addition to the selected papers, the scientific program included two invited lectures by François Bry from the Ludwig Maximilian University of Munich (Germany), and Axel Polleres from the National University of Ireland, Galway (Ireland). We would like to thank them for having accepted our invitation. We would also like to thank all the members of the Program Committee and all the referees for their careful work in the review and selection process. Many thanks to all authors who submitted papers and to all conference participants. We gratefully acknowledge all the institutions and corporations who have supported this event.

Programming and Computer Software, 2000

The problem of verifying macrostructure of websites where information resources are represented by means of HTML is studied. The macrostructure of a website is understood as the structure of interrelations between its resources based on hyperlinks. The approach presented involves inventorying information resources of the site, partial syntactic analysis of its HTML-files, locating their hyperlinks, and, in so doing, reconstructing its macrostructure (the hyperlink graph of resources). The description of the site's macrostructure is placed into a relational database and is analyzed by formal methods based on relational algebra and graph theory in order to detect irrelevant (dangling) hyperlinks, resources to which no inner hyperlink points, as well as hypertext pages unattainable from the homepage of the site. In the paper, the prospects of this approach are discussed in relation to websites created with the help of XML technologies. A brief description of an implemented prototype of a verification system for HTML sites is given.

info.fundp.ac.be

Proceedings of the 2006 international cross-disciplinary workshop on Web accessibility (W4A) Building the mobile web: rediscovering accessibility? - W4A, 2006

Developing Web pages following established standards can make the information more accessible, their rendering more efficient, and their processing by computer applications easier. Unfortunately, more than 95% of the existing Web pages today are not "valid" in that they do not follow some of the recommendations (standards) of the World Wide Web Consortium (W3C). Fixing any Web page to make it standardcompliant is a major undertaking. There is now an open-source tool called HTML Tidy which will attempt to fix the invalid HTML code automatically. However, Tidy often changes the Web page's appearance after processing. It is not an effective tool to transform existing Web pages to make them standard-compliant. In this paper we report the design and implementation of PURE, a tool that cleans up an HTML document through reverse engineering. PURE starts with the rendering result of a given Web page and generates valid HTML code and CSS automatically to produce the same appearance. It is found to be effective for many existing Web pages. A prototype is now available for public testing and comments.

Springer eBooks, 2001

Web design is an inherently error-prone process. To help with the detection of errors in the structure and connectivity of Web pages, we propose to apply model-checking techniques to the analysis of the World Wide Web. Model checking the Web is different in many respects from ordinary model checking of system models, since the Kripke structure of the Web is not known in advance, but can only be explored in a gradual fashion. In particular, the model-checking algorithms cannot be phrased in ordinary µ-calculus, since some operations, such as the computation of sets of predecessor Web pages and the computations of greatest fixpoints, are not possible on the Web. We introduce constructive µ-calculus, a fixpoint calculus similar to µ-calculus, but whose formulas can be effectively evaluated over the Web; and we show that its expressive power is very close to that of ordinary µ-calculus. Constructive µ-calculus can be used not only for phrasing Web model-checking algorithms, but also for the analysis of systems having a large, irregular state space that can be only gradually explored, such as software systems. On the basis of these ideas, we have implemented the Web model checker MCWEB, and we describe some of the issues that arose in its implementation, as well as the type of errors that it was able to find.

In this paper, we present the rewritingbased, Web verification service WebVerdi-M, which is able to recognize forbidden/incorrect patterns and incomplete/missing Web pages. WebVerdi-M relies on a powerful Web verification engine that is written in Maude, which automatically derives the error symptoms. Thanks to the AC pattern matching supported by Maude and its metalevel facilities, WebVerdi-M enjoys much better performance and usability than a previous implementation of the verification framework. By using the XML Benchmarking tool xmlgen, we develop some scalable experiments which demonstrate the usefulness of our approach.

The Journal of Logic and Algebraic Programming, 2013

Keeping XML data in a consistent state w.r.t. both structure and content is a burdensome task. To maintain the consistency of ever-larger, complex XML repositories, suitable mechanisms that are able to fix every possible inconsistency are needed. In this article, we present a methodology for semi-automatically repairing faulty XML repositories that can be integrated on top of an existing rewriting-based verification engine. As a formal basis for representing consistency criteria, we use a rule-based description formalism that is realized in the language Maude. Then, starting from a categorization of the kinds of errors that can be found during the verification process, we formulate a stepwise transformation procedure that achieves correctness and completeness of the XML repository w.r.t. its Maude formal specification while strictly observing the structure of the XML documents. With the aim of increasing the level of automation of our repair methodology, we also define two correction strategies and two completion strategies that reduce either the amount of information to be changed or the number of repair actions to be executed in order to deliver an XML repository that is both correct and complete. Finally, we describe a prototype implementation of the repairing tool, which we use for an experimental evaluation of our method with good results.