Extract Runtime Outputs From a ptr_state

Read the latest plot object, error message, or generated code text from the runtime result stored on a ptr_state. Use these to compose custom UIs or to test the runtime in shiny::testServer.

Usage

ptr_extract_plot(state)

ptr_extract_error(state)

ptr_extract_code(state)

Arguments

state

A ptr_state from ptr_init_state().

Value

ptr_extract_plot returns a ggplot object (or NULL on failure); ptr_extract_error returns a string or NULL; ptr_extract_code returns a single string.

Reactive contexts

Each function wraps its read in shiny::isolate(), so it works in both reactive and non-reactive contexts and returns the current value without establishing a reactive dependency.

Do not call these inside a render*{} block if you want the output to update when the plot rerenders. Because isolate() suppresses the dependency on state$runtime(), the render block fires once on mount and never again. Inside a reactive context, read state$runtime() directly — that takes the dependency and re-fires on every Update plot click. Reserve ptr_extract_* for non-reactive contexts: download handlers, shiny::testServer() assertions, and one-shot reads outside any session.

Examples

shiny::isolate({
  state <- ptr_init_state(
    "ggplot(mtcars, aes(x = wt, y = mpg)) + geom_point()"
  )
  ptr_extract_code(state)
})
#> [1] ""