# Migrate to firefly v14.0

This major version introduces a new first argument to deferred registration functions.

A new first argument is provided to deferred registration functions: a scoped runtime instance.

This new scoped runtime instance argument should be used whenever runtime access is required, instead of the root runtime provided to module registration function.

Reminder: A deferred registration function is a function returned by a module registration function and is executed later, once global data has been fetched. A common use case for deferred registrations is conditionally rendering navigation items.

Placing the runtime argument first is intentional: it emphasizes that consumers should rely on this specific runtime within the deferred registration function scope, rather than the root runtime instance passed to the module registration function.

Before:

The runtime argument of the registration function is used to register the navigation item.

export const register: ModuleRegisterFunction<FireflyRuntime, unknown, DeferredRegistrationData> = runtime => {
    return ({ featureFlags }, operation) => {
        if (featureFlags.featureA) {
            runtime.registerNavigationItem({
                $id: "feature-a",
                $label: operation === "register" ? "Feature A" : "Feature A updated",
                to: "/feature-a"
            });
        }
    };
}

After:

The deferredRuntime argument of the deferred registration function is used to register the navigation item.

export const register: ModuleRegisterFunction<FireflyRuntime, unknown, DeferredRegistrationData> = runtime => {
    return (deferredRuntime, { featureFlags }, operation) => {
        if (featureFlags.featureA) {
            deferredRuntime.registerNavigationItem({
                $id: "feature-a",
                $label: operation === "register" ? "Feature A" : "Feature A updated",
                to: "/feature-a"
            });
        }
    };
}