Complexity Metrics for Cascading Style Sheets

Web applications are becoming important for small and large companies since they are integrated with their business strategies. Cascading Style Sheets (CSS) however are an integral part of contemporary Web applications that are perceived as complex by users and this result in hampering its widespread adoption. The factors responsible for CSS complexity include size, variety in its rule block structures, rule block reuse, cohesion and attribute definition in rule blocks. In this paper, we have proposed relevant metric for each of the complexity factors. The proposed metrics are validated through a practical framework. The outcome shows that the proposed metrics satisfy most of the parameters required by the practical framework hence establishing them as well structured

Tool Support for Cascading Style Sheets’ Complexity Metrics

Tools are the fundamental requirement for acceptability of any metrics programme in the software industry. It is observed that majority of the metrics proposed and are available in the literature lack tool support. This is one of the reasons why they are not widely accepted by the practitioners. In order to improve the acceptability of proposed metrics among software engineers that develop Web applications, there is need to automate the process. In this paper, we have developed a tool for computing metrics for Cascading Style Sheets (CSS) and named it as CSS Analyzer (CSSA). The tool is capable of measuring different metrics, which are the representation of different quality attributes: which include understandability, reliability and maintainability based on some previously proposed metrics. The tool was evaluated by comparing its result on 40 cascading style sheets with results gotten by the manual process of computing the complexities. The results show that the tool computes in far less time when compared to the manual process and is 51.25% accurate

Eliminating Code Duplication in Cascading Style Sheets

Cascading Style Sheets (i.e., CSS) is the standard styling language, widely used for defining the presentation semantics of user interfaces for web, mobile and desktop applications. Despite its popularity, CSS has not received much attention from academia. Indeed, developing and maintaining CSS code is rather challenging, due to the inherent language design shortcomings, the interplay of CSS with other programming languages (e.g., HTML and JavaScript), the lack of empirically- evaluated coding best-practices, and immature tool support. As a result, the quality of CSS code bases is poor in many cases. In this thesis, we focus on one of the major issues found in CSS code bases, i.e., the duplicated code. In a large, representative dataset of CSS code, we found an average of 68% duplication in style declarations. To alleviate this, we devise techniques for refactoring CSS code (i.e., grouping style declarations into new style rules), or migrating CSS code to take advantage of the code abstraction features provided by CSS preprocessor languages (i.e., superset languages for CSS that augment it by adding extra features that facilitate code maintenance). Specifically for the migration transformations, we attempt to align the resulting code with manually-developed code, by relying on the knowledge gained by conducting an empirical study on the use of CSS preprocessors, which revealed the common coding practices of the developers who use CSS preprocessor languages. To guarantee the behavior preservation of the proposed transformations, we come up with a list of preconditions that should be met, and also describe a lightweight testing technique. By applying a large number of transformations on several web sites and web applications, it is shown that the transformations are indeed presentation-preserving, and can effectively reduce the amount of duplicated code in CSS