Using assertions to help end-user programmers create dependable web macros

Abstract

Web macros give web browser users ways to "program" tedious tasks, allowing those tasks to be repeated more quickly and reliably than when performed by hand. Web macros face dependability problems of their own, however: changes in websites or failure on the part of end-user programmers to anticipate possible macro behaviors can cause macros to act incorrectly, often in ways that are difficult to detect. We would like to provide at least some of the benefits of software engineering methodologies to the creators of web macros. To do this we adapt assertions to web-macro programming scenarios. While assertions are well-known to professional software engineers, our web macro assertions are unique in their focus on website evolution, are generated automatically, and encode the expectations and assumptions of a rapidly growing group of users who often have limited formal programming expertise. We have integrated our techniques for assertion generation and evaluation into a web macro tool, and performed an empirical study investigating its use. Our results show that the assertions can help web macro users detect macro failures and correct macro faults.

Fast, Accurate Creation of Data Validation Formats by End-User Developers

“…Toped has been integrated with several end-user development tools, including Visual Studio.NET [18], the Robofox web macro tool [6], and Microsoft Excel [18]. Formats can be reused without modification in each of these programming platforms.…”

“…For example, accountants and financial analysts might create web macro scripts to automatically "screen scrape" data from web pages into spreadsheets [6] [15], and marketing specialists or even administrative assistants might create web applications to receive information directly from people via web forms. This wide range of different users can then write programs to use the collected information for computation, report-generation, or generating new web pages.…”

“…For example, if an end-user developer creates a web macro that scrapes data from a certain place on a web page, and the web page is later modified by the site owner, then the web macro may begin to read incorrect information and malfunction as a result [6] [7]. Even when information is not collected automatically, inputs can still contain errors.…”

“…Previous work described how to algorithmically infer formats from examples [17], how to use Toped formats to validate data in web macro editors and other programming platforms [6] [18], and how to formally model collections of formats [16]. While this work briefly mentions Toped, it does not describe Toped's internal details, nor does it evaluate Toped's expressiveness and usability.…”

Refactoring pipe-like mashups for end-user programmers

“…To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. gineering methodologies to help end users program more dependably in non-traditional language paradigms is not new in the software engineering research literature (e.g., [4,15,22]), this is the first effort targeting the rapidly growing pipe-like mashup domain.…”