Varis: IDE Support for Embedded Client Code in PHP Web Applications

In software development, IDE services are used to assist developers in programming tasks. In dynamic web applications, however, since the client-side code is embedded in the server-side program as string literals, providing IDE services for such embedded code is challenging. We introduce Varis, a tool that provides services on the embedded client-side code. We perform symbolic execution on a PHP program to approximate its output and parse it into a VarDOM that compactly represents all its DOM variations. Using the VarDOM, we implement various types of IDE services for embedded client code including syntax highlighting, code completion, and 'find declaration'.