1. A method, comprising: receiving, at a processor, a source file for preprocessing, wherein the source file comprises source code and is written in a client-side scripting language; parsing, at the processor, the source file; identifying, at the processor, directive information for a preprocessed directive within the source code of the source file, wherein the directive information comprises data on at least a portion of a client-side scripting language file and a mode; creating, at the processor, a version of the source file for the mode, wherein the version of the source file comprises the source code from the source file and the at least a portion of the client-side scripting language file; associating, at the processor, metadata with the preprocessed directive and the version of the source file, wherein the metadata comprises: information regarding which portions of the source file have been altered since a last preprocessing of the source file has occurred, and at least a portion of the client-side scripting language file for generating at least a portion of markup language for a web page to be served to a client device using a webserver; storing the metadata in a database; retrieving, via the webserver from the database, only the metadata associated with the preprocessed directive in the version of the source file such that the entire source file is not retrieved; and in response to receiving a request for the metadata associated the version of the source file, generating, in accordance with the metadata associated with the preprocessed directive and the version of the source file, at least the portion of the markup language for the web page to be served to the client device.