An exploratory study of MVC-based architectural patterns in Android apps

Abstract

Mobile app development now represents a significant part of the software industry, with Android being the largest ecosystem. Android development comes with its own design practices and templates (layouts, activities, etc.). Developers also use different established architectural patterns for designing interactive software such as MVC, MVP and MVVM. They implement these patterns based on their understanding and experience. Thus, the choice and the implementation of such patterns varies from a developer to another. To the best of our knowledge, there is no work that provides a comprehensive view of the use of these patterns in mobile apps. Moreover, there is no clear understanding of which pattern to use and what is the trend for designing mobile apps using such patterns. In this paper, we propose an automatic approach to identify which MVC-based architectural pattern (MVC, MVP and MVVM) is used predominantly in a given app. For this purpose, we defined each of these patterns through a number of heuristics according to the pattern's potential implementations within the Android framework. We conducted an empirical study on a large set of mobile apps downloaded from the Google Play Store. We found, not surprisingly, a dominance of the popular MVC pattern, a rare use of MVP while MVVM is almost unused and a significant number of apps do not follow any pattern. The empirical study also enabled us to analyse the use of these patterns by domain, size and last-update date of the apps. We observed that MVC has been the most used pattern over the past years and it continues to gain popularity, and that small-size apps are mostly the ones that do not use any pattern.