Value Providers API

Since Origins: Math v1.4.2-alpha, resource values are now queried through the Value Providers API. If your mod also contains a "more-precise" value being held by a Power, and you want Origins: Math to recognize it, the Value Providers API is now the proper way to do so.

Registering a Value Provider

To register a Value Provider, you can use the ValueProviders.registerProvider method.

This method accepts a Power class and a ValueProvider<T> instance, which handles the various providers for each "value", such as the Power's value, maximum value and minimum value!

ValueProviders.registerProvider(
    MyCustomPower.class,
    new ValueProvider<>(MyCustomPower::getCustomValue, MyCustomPower::getCustomMax, MyCustomPower::getCustomMin)
);

Registering a Value Modifier

Despite this API's name, it also holds Value Modifiers! As their name suggests, Value Modifiers are objects that allow you to modify the value of a Power class.

These Value Modifiers are used in place of "changing resources", such as the Variable Change Resource (Entity Action Type).

To register a Value Modifier, you can use the ValueProviders.registerModifier method.

This method accepts a Power class and a ValueModifier<T> instance, which handles the various modifiers for each "value", such as adding and setting a value!

ValueProviders.registerModifier(
    MyCustomPower.class,
    new ValueModifier<>(MyCustomPower::setCustomValue, MyCustomPower::addCustomValue)
);

Value Provider and Modifier Priority

For a specific Power instance, the priority of ValueProvider A and ValueProvider B depend on the Power's class inheritance, where a more "recently" inherited class, i.e. a class deeper in the inheritance chain, will have higher priority.

For instance, say that a Power instance is an instance of MyCustomPower, where the MyCustomPower class follows the given inheritance chain, where for A > B, B extends A:

Power > VariableIntPower > MyAbstractCustomPower > MyCustomPower

If a ValueProvider for both MyAbstractCustomPower and VariableIntPower exist, the ValueProvider for MyAbstractCustomPower takes the higher priority, as it is more deeper in the inheritance chain than VariableIntPower.

However, if no ValueProvider exists for both MyCustomPower and MyAbstractCustomPower, then the value provider for VariableIntPower will be used instead, given that a ValueProvider for it exists and is registered.

If no ValueProvider exists for all classes in the inhertiance chain of the Power instance, an IllegalArgumentException is thrown instead of returning a null value.

The rules for the priority of a ValueModifier follow the same rules as those governing the priority of a ValueProvider, discussed in this section.