Olav Junker Kjær takes us through how browser-based JavaScript deals with events and default action, including the dispatch sequence of events, when they are bubbled and captured and the order of these events. Also shows some setTimeout() tricks to deal with long-running JavaScript
As web pages become more and more like applications, code performance becomes more and more important. This article looks at a number of performance issues to avoid, in EcmaScript, DOM and AJAX requests. Covers eval, the with keyword, try/catch in performance-critical code, global variables, implicit object conversion, string concatenation, primitive operations over function calls, repainting and reflowing documents, modifying elements, using XPath.