A method (and structure) for enacting changes to a document containing a template-based program that transforms tree-structured data from a first tree-structured data into a second tree-structured data, including providing an interface to permit selection of a document containing the template-based program, constructing a model of the template-based program in the selected document by parsing elements of the template-based program into a corresponding logical construct having a match condition and at least one generator, where the match condition determines whether an element in the first tree-structure data is to be processed by one or more of the at least one generator, and displaying a representation of the model to the user.