Function useShinyInputValue

useShinyInputValue<T>(
id: string,
options?: { namespace?: string | null },
): T | undefined
A read-only React hook that subscribes to a Shiny input value created by a separate producer component (typically one that calls useShinyInput and holds the setter).

Use this when a component only needs to read an input value — it makes data flow direction visible at the call site and prevents accidental writes to inputs the component does not own.

Mount ordering is handled: if this hook runs before the producer's useShinyInput effect attaches, the subscription is queued in the input registry and fires the moment the entry is created.
Type Parameters
- T
Parameters
- id: string
  The Shiny input ID to subscribe to (input$<id>).
- options: { namespace?: string | null } = {}
  Optional configuration object.
  - Optionalnamespace?: string | null
    
    Module namespace to apply (or null to suppress the surrounding ShinyModuleProvider namespace).
Returns T | undefined
The current input value, or undefined if no producer has registered the ID yet.
- Defined in src/shiny-react/use-shiny.ts:396