John Hughes. Building a WordPress Plugin Series. Torque, 2016.
This series is great in many ways (covers a broad spectrum, recommends a number of other resources), but has a few significant weaknesses that keep it from being the gold standard, namely: the code samples oftentimes don’t mention exactly where they are supposed to go; a lot of things happen in the code that aren’t explained; certain parts feel very rushed.
Introduces us to WordPress Plugin Boilerplate, which seems to have good principles but I’m not seeing actually used as a framework in popular plugins I’ve evaluated.
We create a Custom Post Type, the method in which Hughes’ defines the CPT is a bit verbose for my liking, recommending looking at other articles on this subject.
Suggests using a method similar to Genesis where “the entire theme is made up of hooked callback functions and template parts which can be unhooked and/or filtered before they output to the browser.”
Covers why it is okay to include custom templates in our plugins sometimes, how Tom organizes his template code, examples of single and archive templates, etc.
While older this is a classic article on template file loaders and uses Gary Jones’ Gamajo Template Loader, there is also a git repo with a working plugin example.