Here are various recipes for things you might need in a classification/catalogue site, the sort that might be used by a small bookseller or an independent publisher such as Green Man Press, a CMS-based (content-management system) site I created for a client. The recipes here are working examples for a tutorial on what's possible using the Grav CMS, using the tools straight from the box with no customisation.
The tutorial and code examples can be downloaded from XXX. Grav itself you will need to fetch from the Grav site. You will need to know the basics of Grav (which can readily be learnt from the Grav documentation, mostly excellent). All these recipes employ the very simplest approaches, to make them easy to understand and to give a springboard for development.
Part 1 deals setting up data structure, using book selling as the example domain. Menu items are:
Some of the layout might seem unsatisfactory, but that's because I used the default Grav theme, 'Antimatter', without customisation, to keep the exposition simple and to make the recipes easy to port to other sites.
Part II of the tutorial deals with the more specifically with the back end, not visible to the site visitor: how to input data using the Admin interface, how to use a blueprint to create input forms for different data structures, and how to change the Grav theme.
Please note that the tutorial and this website, including all the code examples, are copyright © T R G Green 2016.