Basic configuration handling in eZ Publish is similar to what is commonly possible with Symfony. In this regard, you can define key/value pairs in your configuration files, under the main parameters key (like in parameters.yml).
Internally and by convention, keys follow a dot syntax where the different segments follow your configuration hierarchy. Usually keys are prefixed by a namespace corresponding to your application.
Values can be anything, including arrays and deep hashes.
In eZ Publish, it is fairly common to have different settings depending on the current siteaccess (e.g. languages, content view provider configuration...).
Dynamic configuration can be resolved depending on a scope.
Available scopes are (in order of check) :
It gives the opportunity to define settings for a given siteaccess for instance, like in the legacy INI override system.
This mechanism is not limited to eZ Publish internal settings (aka ezsettings namespace) and is applicable for specific needs (bundle related, project related...).
How it works
Dynamic configuration is handled by a config resolver. It consists in an object exposing mainly hasParameter() and getParameter() methods:
hasParameter() can take 3 different parameters:
$paramName(i.e. the name of the parameter you need)
$namespace(i.e. your application namespace, myapp in the previous example. If null, the default namespace will be used, which is ezsettings by default)
$scope(i.e. a siteaccess name. If null, the current siteaccess will be used)