Returns the server's (already sanitized) error, or null when the output is
not in the "error" state. message is the condition/exception text — the
same text vanilla Shiny paints into the output element — unless the app has
shiny.sanitize.errors / sanitize_errors on, in which case the server
sends its generic message instead. call and type are R-only extras;
Python sends null for both.
Silent errors (req(), and validate() with no message) never reach this
hook: the server sends them with an empty message, which shinyreact treats
as a null value rather than an error.
Parameters
outputId: string
The ID of the Shiny output to subscribe to.
options: {namespace?:string|null} = {}
Optional configuration object.
Optionalnamespace?: string|null
Module namespace to apply (or null to suppress
the surrounding ShinyModuleProvider namespace).
Hook to subscribe to the error of a Shiny output.
Returns the server's (already sanitized) error, or
nullwhen the output is not in the"error"state.messageis the condition/exception text — the same text vanilla Shiny paints into the output element — unless the app hasshiny.sanitize.errors/sanitize_errorson, in which case the server sends its generic message instead.callandtypeare R-only extras; Python sendsnullfor both.Silent errors (
req(), andvalidate()with no message) never reach this hook: the server sends them with an empty message, which shinyreact treats as anullvalue rather than an error.