injectContextSync

injectContextSync<T>(el: Element, key: ContextKey<T>): T | undefined

The nearest provided value, synchronously, or undefined.

Usage

const value = injectContextSync(el, Key);

if (value === undefined) {
  // no provider — fall back, or do nothing
}

When to reach for it

When the answer is optional and the caller has a fallback. undefined means "no provider right now", which is a different statement from $inject()'s "not yet".

The canonical pair is a look-up-or-create:

const channels =
  injectContextSync(el, DataChannels) ?? provideRootContext(DataChannels, () => new Map());

From a component

$injectSync(key) is the same call with the element filled in.

It answers for right now

A provider that mounts later is not seen, because there is no request left pending. If mount order is not something you control, use injectContext() or subscribeContext().