Using classes and packages

The first major difference between L^ATEX 2.09 style files and L^ATEX2_e packages and classes is that L^ATEX2_e supports modularity, in the sense of building files from small building-blocks rather than using large single files. A L^ATEX package or class can load a package as follows:

   \RequirePackage[<options>]{<package>}[<date>]

For example:

   \RequirePackage{ifthen}[1994/06/01]

This command has the same syntax as the author command \usepackage. It allows packages or classes to use features provided by other packages. For example, by loading the ifthen package, a package writer can use the `if...then...else...' commands provided by that package. A L^ATEX class can load one other class as follows:

   \LoadClass[<options>]{<class-name>}[<date>]

For example:

   \LoadClass[twocolumn]{article}

This command has the same syntax as the author command \documentclass. It allows classes to be based on the syntax and appearance of another class. For example, by loading the article class, a class writer only has to change the bits of article they don't like, rather than writing a new class from scratch.

The following commands can be used in the common case that you want to simply load a class or package file with exactly those options that are being used by the current class.

   \LoadClassWithOptions{<class-name>}[<date>]
   \RequirePackageWithOptions{<package>}[<date>]

For example:

   \LoadClassWithOptions{article}
   \RequirePackageWithOptions{graphics}[1995/12/01]