I'm new to WordPress, and I'm building some backend logic to it. I want the admin to have as smooth experience with it as possible. I want for him to be able to run the website with "a click of a button".

I'm used to Java and nodeJS environments, where I have life cycle, where I can specify logic to happen when the server starts, but I'm having trouble to understand how it's done in WordPress(or PHP for that matter).

I want the website to check the database and see if it has needed tables for it's functioning, and if not, to create them and fill them with relevant data, as well as to check if the database is up-to-date (in case of a long crash), and update if necessary.

Right now I'm thinking about running a Cron script to check it, every few minutes but it's heavy on resources. A better solution might be to run it on the first interaction with a user, but it seems not ideal, as it will slow him down.

Is there a life cycle in WordPress? should I be worried about it crashing during important operation and then starting on it's own? Can I specify logic for it to run on it's boot/restart?

CodePudding user response：

I am not completely sure what you have in mind when you say "fill them with relevant data", but I would either recommend, leveraging WordPress' own logic or complete your task using other tools.

Just like any php script, it is stateless and it has an index.php as starting point. Then files are loaded in order and the contents of your request and the environment will depend where you end up. This is just how php works and the key difference with JS is that JS executed on your computer, and php is a set of server side scripts that are compiled and will produce some sort of output that is sent back to your browser, just like when you call a REST api.

You might want to take a look at the following things:

wp-load.php: the file that will look for your constants defined in wp-config.php, when this file is not yet present it will redirect you to the "famous" wordpress site setup (after loading a bunch of stuff related to database connections and request data). You could follow the logic, but I would advise agains that. This due to the fact that the WordPress core is very old and this gives you an example of how php applications from the early 2000s used to look like and will most likely cause headaches.

Existing tools

Not only on server level, but also things like wp-cli or maybe a composer based solution like roots/bedrock or even roots/wordpress.

To answer your question about lifecycles directly

Yes, WordPress offers an old-timey hook system, but this is just during the request lifecycle for an active install, so this wouldn't be exactly what you seem to be looking for.

Finally, it is good to have some understanding of the internal workings of WordPress, but the whole reason that WordPress is easy to run and compatible with many setups, is just because they "strive for forever backwards compatibility" (which is also why they don't use semantic versioning). Which in turn means that the core is very outdated and unreadable, so I wouldn't bother trying to figure it out yourself.

And even more so I wouldn't want you to think that this is a fair representation of the PHP-world, since the initial release of WordPress, the language has completely evolved and most of the key components to it being a nice developer experience were still a long way ahead.

In short, I'd look for existing solutions which are built for your specific server setup and if that is not possible for some reason, try to find some sort of CLI tool in php, or other languages.