Discovering User-Defined Event Handlers in Presence of JavaScript Libraries

JavaScript libraries, such as JQuery, are widely used in web applications. In these libraries´ event delegation models, a DOM element´s event handler is usually bound to its parent nodes. This makes it difficult for developers to figure out the user-defined event handlers of a specified DOM element. In this paper, we propose an approach that identifies the user-defined event handlers of DOM elements in a web page. We dynamically collect the execution trace for each triggered event in a web page, and analyze how each function is used in the execution trace to discover the event handlers for each event. We evaluate our approach on seven real-world web applications. The result shows that our approach is effective, with an overall precision of 100% and recall of 99.8%.