1. A method in a computing system for generating an extensible stylesheet, the method comprising: receiving a target file in a markup language, the target file including a plurality of dynamic objects; receiving a structure tree, each node of the structure tree corresponding to one of the dynamic objects in the target file; creating a data structure by associating each of the dynamic objects in the target file with at least one element in at least one source file by a meta-tag; and generating, from the data structure, the extensible stylesheet in reference to the target file, wherein the stylesheet, when applied to the target file, controls visual aspects of how the target file is displayed; wherein said associating each of the dynamic objects in the target file with at least one element in at least one source file by a meta-tag comprises: copying each of the dynamic objects into a corresponding one of the elements in the at least one source file, or creating or updating an identifier to link each of the dynamic objects with the corresponding one of the elements in the at least one source file; and traversing the structure tree to obtain related information for one or more of the meta-tags, wherein the related information includes an association between the at least one dynamic object and the corresponding element in the at least one source file.