useContext

Reads the nearest provided value of context. Falls back to its default; throws when there is neither a provider nor a default, because no correct value exists. The lookup follows the current owner, so call it while a component runs (or in an effect or memo it creates), not after an await or in an event handler. The read is not tracked.

Import#

import { useContext } from "@shadow-js/core";

Signature#

function useContext<T>(context: Context<T>): T

Parameters#

Returns#

The value of the nearest provider above the current owner, else the default value.

Throws#

• ShadowError CONTEXT_MISSING when no provider is above the current owner and the context's default is undefined.

Examples#

import { createContext, useContext } from "@shadow-js/core";

const User = createContext<{ name: string }>();

function Greeting() {
  const user = useContext(User); // throws CONTEXT_MISSING without a provider
  return <p>Hello, {user.name}</p>;
}