Bootstrap Helpers

Bootstrap Helpers

Butterfly API provides two small helpers for initialization code that should only run once:

• Bootstrap
• RunOnce

Bootstrap

Bootstrap groups one or more initialization steps and prevents them from being executed more than once.

Create one with:

private static final Bootstrap BOOTSTRAP =
        Bootstrap.create();

Then run your initialization:

public static void init() {
    BOOTSTRAP.run(
            ModItems::init,
            ModBlocks::init,
            ModSounds::init
    );
}

The first call runs every supplied step.

Later calls do nothing.

Checking Whether It Ran

BOOTSTRAP.hasRun();

Returns true after the bootstrap successfully runs.

Return Value

run(...) also returns a boolean:

boolean ran = BOOTSTRAP.run(
        ModItems::init,
        ModBlocks::init
);

It returns:

true

when the initialization runs for the first time.

It returns:

false

when the bootstrap has already run.

RunOnce

RunOnce is the smaller version of the same idea.

Create one with:

private static final RunOnce INIT =
        RunOnce.create();

Then:

public static void init() {
    INIT.run(() -> {
        // initialization
    });
}

Checking RunOnce

INIT.hasRun();

Like Bootstrap, run(...) returns true when the action runs and false when it has already run.

Bootstrap vs RunOnce

Use Bootstrap when initialization naturally consists of multiple steps:

BOOTSTRAP.run(
        ModItems::init,
        ModBlocks::init,
        ModEntities::init
);

Use RunOnce when you simply need to protect one action:

INIT.run(ModItems::register);

Both helpers are designed to prevent accidental duplicate initialization.