Config system used to provide an add_static_source method, which was intended for
use by Extensions to add statics. But extensions for a class arent initialised
until at least one instance of that class is created, so before that the
Config system didnt include values from extensions
This patch reverses the control flow, so that the Config system explictly asks
each Object for its additional config sources via the new method
get_extra_config_sources. This method returns an array that can contain
string names of classes and also raw associative arrays.
The developer visible change is that Extension#add_to_class has been
deprecated. Instead there is a new method, get_extra_config, which has
the same method signature but needs to guarantee that it doesnt
cause side effects. Additionally there is no need to call
parent::get_extra_config - this is handled automatically.
BUGFIX Versioned's constructor doesn't provide suitable defaults. Previously a bug/feature in singleton, where it would pass null,true as params to strong_create, which would then get passed through as params to Versioned's constructor, meant that the code still executed fine (as was set to something that wasn't an array, so the null and true were instead taken as args). The fact that the usage of singleton(Versioned) never really used the classes code, purely for value lookup, meant that this never propagated errors. I've now switched singleton() to use the injector for retrieving values, which means these dud values are no longer passed through
CHANGE Given that Config::inst is an implementation of the singleton pattern itself, I've removed the extra call to singleton(). A side effect of this is that it gets around a possibly nasty circular reference with the dependency injector (which relies on the config object); in future, this dependency structure should really be structured from the DI directly.
MINOR Change singleton and strong_create to use dependency injector
CHANGE Given that Config::inst is an implementation of the singleton pattern itself, I've removed the extra call to singleton(). A side effect of this is that it gets around a possibly nasty circular reference with the dependency injector (which relies on the config object); in future, this dependency structure should really be structured from the DI directly.
MINOR Change singleton and strong_create to use dependency injector
