1. A method for adding directives for JavaScript files directly into source code, comprising: receiving a source file for preprocessing, wherein the source file is written in a client-side scripting language; parsing the source file; identifying directive information for within the source file; associating metadata with the directive during preprocessing; retrieving metadata associated with a preprocessed directive; receiving a request to access metadata associated with a preprocessed directive in the source file, wherein the preprocessed directive is the directive from the source file; and generating at least a portion of markup language for a web page in accordance with metadata associated with the preprocessed directive in response to the request.