Configs

Adding configs to your addon

In order to add configs to your addon, create a directory called configs in resources. There, you can add all your .yml configs, which will automatically be extracted and handled the same way all Nova configs are.
New or changed keys will automatically be added / updated on the server as well, unless they have been modified by an admin.

Accessing configs

To access the configs, retrieve them from NovaConfig.
You can either use their names:

NovaConfig["example:ruby"] // namespace:name (drop the .yml)

Or if the name matches the name of one of your items, the NovaMaterial:

NovaConfig[Items.RUBY]

Provider

To help with config reloading, Nova offers the Provider class. This class stores a value of a given type and can be delegated to. Providers have an abstract loadValue function that, depending on its implementation, might load something from a config, a CBF Compound, or anything else.
Providers associated with configs will automatically reload their values when the config is reloaded.
You can also chain value modification calls on a Provider. Those modification steps will then be run every time the config is reloaded.

Some of those modification functions are:

• map - Maps the value to a new value.
• orElse - Falls back to a default value if the value is null.
• flatMap - Performs a flatMap operation for a Provider<List<*>>.
• flatten - Performs a flattening operation for a Provider<List<List<*>>>.
• requireNonNull - Throws an exception if the value is null.

Every time such a modification function is called, a new Provider is created and returned. This allows you to create several modified versions from the same Provider.

You might also be interested in these Provider-related top-level functions:

• provider - Creates a static Provider from a given value.
• combinedProvider - Creates a Provider<List<T>> from a list of Provider<T>s.
• lazyProvider - Creates a Provider whose parent is only created lazily using the given initializer lambda.
• combinedLazyProvider - Creates a Provider<List<T>> from a list of Provider<T>s, where the Provider<T>s are created lazily using the given initializer lambda.
• lazyProviderWrapper - Creates a Provider that wraps a lazily initialized static value from given initializer lambda.

configReloadable

The easiest way to create a Provider that is affected by config reloading is to use the configReloadable function:

object Example {
    val SOME_VALUE: Int by configReloadable { NovaConfig[Items.RUBY].getInt("some_value") }
}

Or if you need to pass the Provider somewhere, don't delegate:

object Example {
    val SOME_VALUE: Provider<Int> = configReloadable { NovaConfig[Items.RUBY].getInt("some_value") }
}

Or if you're required to pass a Provider, but the value actually isn't configurable nor reloadable:

val someValue: Provider<Int> = provider(0)

ConfigAccess

You can also create entire classes that provide access to a config file. For that, inherit from ConfigAccess. Then, you can call getEntry<Type>(key) or getOptionalEntry<Type>(key), which will return a Provider for that value.

Example ConfigAccess Implementation

FoodOptions.kt

private class ConfigurableFoodOptions(material: ItemNovaMaterial) : ConfigAccess(material) {

    val type: FoodType by getOptionalEntry<String>("food_type")
        .map { FoodType.valueOf(it.uppercase()) }
        .orElse(FoodType.NORMAL)
    val consumeTime: Int by getEntry<Int>("consume_time")
    val nutrition: Int by getEntry<Int>("nutrition")
    val saturationModifier: Float by getEntry<Float>("saturation_modifier")
    val instantHealth: Double by getOptionalEntry<Double>("instant_health").orElse(0.0)
    val effects: List<PotionEffect> by getOptionalEntry<List<PotionEffect>>("effects")

}

Saving the Provider instance

Instead of delegating to the Provider, you might also find it useful to save the Provider instance in a property, and then create a second property that delegates to that Provider. This way, you can access the Provider instance to do further modifications to the value, without having to worry about config reloading not working.