# Blocking

Presents one blocked transition and the three ways its owner can settle it.

## Signatures

```ts
export interface Blocking extends BeforeNavigationEvent {
    readonly cancel: Effect.Effect<Destination>;
    readonly confirm: Effect.Effect<Destination>;
    readonly redirect: (urlOrPath: string | URL, options?: NavigationNavigateOptions) => Effect.Effect<Destination>;
}
```

## Why

Confirm, cancel, and redirect are explicit Effects so a UI cannot accidentally settle navigation
merely by reading state. Only the first settlement of the active block changes it.

## Ownership and lifetime

The Scope that registered the blocker owns this value's deferred settlement. `confirm` resumes the
original transition, `cancel` keeps the current destination, and `redirect` starts a replacement.

## Property: cancel

Cancels the outstanding blocked transition.

## Property: cancel: Why

Cancellation explicitly keeps the current destination and releases the deferred transition.

## Property: cancel: Ownership and lifetime

Running `cancel` completes the owned Deferred with the current Destination and clears only this
blocker instance's outstanding transition.

## Property: confirm

Confirms and resumes the outstanding blocked transition.

## Property: confirm: Why

Settlement is an Effect, so merely observing blocking state cannot accidentally navigate.

## Property: confirm: Ownership and lifetime

Running `confirm` completes the owned Deferred with the original navigation Effect. The blocker
Scope keeps ownership until that Effect settles or the Scope closes.

## Property: redirect

Replaces the outstanding blocked transition with another destination.

## Property: redirect: Why

Blocked flows can choose a safe destination without first committing the rejected one.

## Property: redirect: Ownership and lifetime

Running `redirect` completes the owned Deferred with a replacement navigation Effect. The
original proposed transition is never committed by this settlement.