Modular Asynchronous Web Programming: Advantages & Challenges

Because of the success of the Internet technologies, traditional standalone applications like Spreadsheet and Drawing are now provided as Web Applications. These adopt asynchronous programming that provides high responsive user interactions. At the same time these applications can grow and make their maintenance harder, turning Modular Programming an attractive practice because of its concept of dividing concerns in separated modules. However, it’s difficult to combine asynchronous methods and modular programming because the first requires uncoupling a module into two sub-modules, which are non-intuitively connected by a callback method. It can spawn the creation of other two issues: callback spaghetti and callback hell. Some proposals have been developed to reduce the issues about modular programming. In this paper, we compare and evaluate them applying them to a non-trivial open source application, the FlickrSphere. Then, we will discuss our experience.