For the sake of demonstrating the ePublisher Designer transform process let us assume a fictional pizzeria in New York City. Further, we’ll say that a bag of pizza ingredients in the refrigerator is our source document. While that bag of ingredients is perfectly nice, it isn’t particularly useful to anyone. The chef needs to transform the ingredients into something useful to him, a cooked pizza. In ePublisher Designer, the ingredients are our source document, the pizza oven is XSL, and the cooked pizza is our output target.

Unfortunately, it isn’t possible simply to throw the ingredients into the oven and then remove a pizza ten minutes later. The bag of ingredients must first be prepared so the oven can deal with the ingredients in a way that is useful to us. In ePublisher Designer, the process of rolling out the dough, and spreading the sauce and cheese is the first stage where a source document is prepared for XSL (the oven) to do it’s job.

Experienced chefs understand that the cooking process is a series of chemical reactions of food to heat. The dough becomes crisp, the cheese melts, etc. The process creates what any reasonable person would define as a pizza. In ePublisher Designer, XSL (the oven) is applying a series of steps (cooking) that are changing our source document (uncooked pizza) into the output target (something the customer is willing to consume).

Just as the pizza chef can customize the pizza ingredients any number of ways, such as cooking the pizza longer or at a different temperature to get different results, the ePublisher Designer user may customize the XSL process to affect his source document.