requireContext()function

requireContext(context: Context<T | null>, caller?: AnyCaller): T

requireContext(context: Context<T | undefined>, caller?: AnyCaller): T

requireContext(context: Context<T>, caller?: AnyCaller): T

Param	Type
`context`	`Context<T` `null>`	The React `Context` to read the current value of. required
`caller`	`AnyCaller`	Function to attribute the thrown `RequiredError` to (defaults to `requireContext`).
`context`	`Context<T` `undefined>`	required
`caller`	`AnyCaller`	Any calling function or constructor, usually referring to something that can call in the current scope that can appear in a stack trace.
`context`	`Context<T>`	required

Return
`T`	The current context value, guaranteed non-nullish.
`T`

Throws
`unknown`	RequiredError If the context value is `null` or `undefined` (i.e. used outside its provider).

Use the value of a React Context, or throw RequiredError if the context was unset.

Reads the context with React's use(), so it must be called inside a component or hook.
Treats both null and undefined as "unset" and throws, naming the context's displayName in the message.

Reads a React context and throws RequiredError if the value is null or undefined. Use it instead of use(context) when a context must be provided by an ancestor — every require*() hook in the library follows this pattern.

Things to know:

Reads the context with React's use(), so it must be called inside a component or hook.
Treats both null and undefined as "unset" and throws, naming the context's displayName in the message.
Pass the calling function as caller so the thrown RequiredError is attributed to it (defaults to requireContext itself).

Usage

import { requireContext } from "shelving/ui";

function requireNavigation(): NavigationStore {
  return requireContext(NavigationContext, requireNavigation);
}

Examples

const theme = requireContext(ThemeContext);