Base/com.mapbox.navigation.base.middleware/MiddlewareRegistry

MiddlewareRegistry

open class MiddlewareRegistry<Context : MiddlewareContext> : CoroutineMiddleware<Context>

This registry allows you to keep track of multiple middleware and multiple contexts. It defines a single level hierarchy where there is the parent context, and optional children contexts.

You can define a parent MiddlewareContext for the registry. Children middleware will have access to the parent context as long as they are registered and the parent context is attached. You can also define MiddlewareContextFactory which is used to construct context from the parent MiddlewareContext. The child context can not have a lifecycle outside of the parent context; in other words, when the parent context is detached, all the children are detached. You control the lifecycle of the children context with the register, unregister functions.

Constructors

MiddlewareRegistry

constructor()

Properties

val isAttached: Boolean

Returns current state of middleware, true if already attached, false otherwise

val middlewares: StateFlow<Set<Middleware<*>>>

A flow representing the current set of registered middleware instances.

Functions

fun context(): Flow<Context?>

fun detach()

Function called to detach middleware context if it exists

fun <R> execute(block: Context.() -> R): R?

Executes a block within the middleware context if available

fun <M : Middleware<Context>> getMiddleware(clazz: KClass<out M>): M?

Retrieves a single middleware instance of a given class type.

fun <M : Middleware<Context>> getMiddlewares(clazz: KClass<out M>): List<M>

Retrieves all middleware instances of a given class type

launchOnAttached

fun launchOnAttached(block: suspend Context.() -> Unit): Job

Launches a suspending block when the registry is attached

inline fun <C : MiddlewareContext, M : Middleware<C>> middlewares(): List<M>

observeMiddlewares

fun <M : Middleware<Context>> observeMiddlewares(clazz: KClass<out M>): Flow<Set<M>>

Observes middleware instances of a given class type.

open override fun onAttached(middlewareContext: Context)

Attaches all registered middleware instances when the registry is attached

open override fun onDetached(middlewareContext: Context)

Detaches all registered middleware instances when the registry is detached

fun register(middleware: Middleware<in Context>): MiddlewareRegistry<Context>

Registers a middleware instance

fun <C : MiddlewareContext> register(middleware: Middleware<C>, factory: MiddlewareContextFactory<Context, C>): MiddlewareRegistry<Context>

Registers a middleware instance with a context factory

repeatOnAttached

suspend fun repeatOnAttached(block: suspend Context.() -> Unit)

Executes a suspending block whenever the registry is attached

fun <C : Context> unregister(middleware: Middleware<C>): MiddlewareRegistry<Context>

Unregisters a middleware instance

fun unregisterAll(): MiddlewareRegistry<Context>

Unregisters all middleware instances.