How do I correctly inform the system about my module's new config?

Question

I'm working on a module that already comes with a config file in mymodule/config/install/mymodule.settings.yml, and I'm working on a new feature that requires its own set of configuration in mymodule/config/install/mymodule.newfeature.yml.

I assume I need to put the following code in an update hook.

function mymodule_update_8003() {
  \Drupal::service('config.installer')->installDefaultConfig('module', 'mymodule');
}

But if I do this, will sites that have overridden my existing configuration (from mymodule.settings.yml) get hosed, or is there another way to tell Drupal about my new configuration?

Answer 1

I think I found a strategy that is only slightly hackish to let Drupal know that your module has created a new config. This solution assumes that your new config is in a separate yml file in yourmodule/config/install but it should be adaptable to a situation where you are adding a new config to an existing file....

/**
 * Install new config.
 */
function your_module_update_8003() {
  // Get all current configs for Your Module.
  $existing_settings_config = \Drupal::configFactory()->getEditable('your_module.settings');
  $existing_foo_config = \Drupal::configFactory()->getEditable('your_module.foo');
  $existing_bar_config = \Drupal::configFactory()->getEditable('your_module.bar');

  // Install the new configuration 
  // (a new file was added a your_module/config/install/your_module.baz.yml)
  \Drupal::service('config.installer')
    ->installDefaultConfig('module', 'your_module');

  // Reset the existing configs in case they were changed when installing the
  // new configuration.
  $existing_settings_config->save();
  $existing_foo_config->save();
  $existing_bar_config->save();
}

It's not ideal, but it seems to work.

Answer 2

"will sites that have overridden my existing configuration (from mymodule.settings.yml) get hosed" Have you tried this?

A) I would suggest, to do separate configuration files (as granular as your updates need to be) and address them and update them separately, not using the "installDefaultConfig" method.

B) Have only one file, however in the updatehook don't call the config installer, but write the updateHook with "entityDefinitionUpdateManager" or any other service, custom php code you need.

On the other hand I totally agree: module default/update configuration system is really foggy.