Codeigniter: Custom config or constant?

Question

I have some global settings variables I need to store for my application, but I'm confused as to whether I should use a custom config file or just add new constants to the bottom of the config/constants.php file? These variables won't be changing once set, so are constants the right choice?

What's the difference between the two, and how does Codeigniter handle them?

Answer 1

Custom config file IMO. That will make your life easier down the line when you decide to upgrade to a new major release of CI, since you'll be able to overwrite config.php without losing critical application constants.

The application-wide config.php is always loaded, so anything you put in there will be globally available, whereas custom config files can be loaded on-demand, saving resources and providing better separation of code responsibilities.

Example: On-demand loading of a config file:

$this->config->load('filename');