Out of Many, One:
Merging Modular Files

Modular systems provide an additional layer of control for HTML Help projects. When a project grows too large for one author to work with at one time, the modular approach allows the project to be split among multiple authors or scheduled for incremental development. Update modules can also be shipped to the customers (or distributed via the Internet), allowing you to add newly available information without requiring a new installation or disturbing the currently installed application and HTML Help system.

Modular HTML Help systems are also invaluable when the project involves different types of expertise or a variety of “plug-in” modules that users purchase separately from the main module. For example, the tree-planting project used for the overview (see Chapter 2: “So How Does It Work? Process & Product Overview”) put the bulk of its content within a main file named tree.chm, but suggested creating individual files with plants specific to each planting zone (i.e., zone01.chm, zone02.chm, etc.). Tree.chm, installed with the original product, is complete in itself, but also contains provision (in the form of a project merge statement and INCLUDE statements in the table of contents) for the integration of the planting zone files. Not only does this approach allow multiple authors to work on the subordinate products, but the marketing department will like this idea of add-ons to generate additional revenue. The same idea could be used in a financial product (with separate modules for home and business, or accounts receivable and accounts payable), graphics products (with modules for separate filter packs), etc.