Separate chapters, each with individual preface, included in same document

Question

I have a document I want to split up into individual sections. I'd like each individual section to be independently compilable, but of course I also need the whole document to compile.

The trouble is, each of my individual sections requires a large preface (\usepackage calls, command definitions, etc.) that I am including with either \input or \include. The preface includes the \documentclass command, so I end up getting ! LaTeX Error: Can be used only in preamble. if I try to compile the whole document.

I'm already using \usepackage{subfiles}, but it doesn't seem to solve the problem.

Answer 1

The best package for this is the standalone package and class. There are numerous examples on this site.

You might want to collect all your packages and preamble into a separate file so that this file can be included both in the main document and the sub documents.