svelte/selector-lifecycle

The lifecycle_outside_component error occurs when a selector readable is created outside component initialization, since selectFoo() depends on getContext(). Capture readables at top-level component init, and use selectFoo.select(state, args) for one-shot reads in handlers, callbacks, or after await.

Use the selector's .select(state, args) form with the initialized Store instance captured outside the handler, for example selectItem.select(appStore.state, itemId). This performs a one-shot read without requiring Svelte context.

Use the selector's .effect(args) form with yield* inside sagas instead of passing the selector object to the saga select effect. For reacting to selector value changes, use selector-channel helpers with plain arguments.

Calling selectFoo() in a template expression violates lifecycle guidance even when caching reuses the readable. Capture the readable once during component initialization and render the captured value with the $value$ auto-subscription syntax.

selectFoo() uses Svelte context and returns a readable store, so it only works during component initialization. selectFoo.select(state, args) returns the plain value directly and works in handlers, tests, and selector composition without context.