How do I set a variable in the configuration file setting.php and use it from code?

Question

How do I set a variable in the configuration file setting.php and use it from code?

Answer 1

in settings.php:

$conf['yoursite_something'] = 5;

Then, in your code:

// Second argument is the default.
variable_get('yoursite_something', NULL);

Make sure to prefix the variables, either with the module you're using it in or with the site name.

Answer 2

Do note that it is not required to declare persistent variables in settings.php. You can simply call variable_get() from your code and define a default value in case the variable is not set. For instance, the following code will say hello on every page request as long as the 'mymodule_say_hello' variable is not explicitly set to 0:

<?php
function mymodule_init() {
  // Get the mymodule_say_hello variable or use 1 if it's not set. 
  if (variable_get('mymodule_say_hello', 1)) {
    drupal_set_message('Hello world');
  }
}
?>

If needed, your module could publish a form that allows the admin to turn of this feature (the system_settings_form function makes that really easy) or you could change the settings programmatically by calling variable_set('mymodule_say_hello', 0).

Answer 3

Drupal 8

In your settings.php:

$settings['foo'] = 'bar';

In your code:

use Drupal\Core\Site\Settings;

Settings::get('foo', 'mydefaultvalue');