module_transform_data: Apply 'teal_transform_module' decorators to reactive...

In teal: Exploratory Web Apps for Analyzing Clinical Trials Data

Apply teal_transform_module decorators to reactive teal_data

Description

Shiny module pair (srv_transform_teal_data / ui_transform_teal_data) that runs a sequence of teal_transform_module() decorators against a reactive teal_data object. Decorators are applied one after another via Reduce, so each one receives the output of the previous as its data argument. Failed transformators are tracked and any downstream transformator is automatically disabled until the failure is resolved. An optional expr argument allows additional code to be evaluated on the final decorated output.

Usage

srv_transform_teal_data(
  id,
  data,
  transformators,
  modules = NULL,
  is_transform_failed = reactiveValues(),
  expr
)

ui_transform_teal_data(id, transformators, class = "well", ...)

Arguments

id	(character(1)) shiny module instance id.
data	(teal_data, teal_data_module, or reactive returning teal_data) The data which application will depend on.
transformators	(list of teal_transform_module) decorator modules to apply sequentially to data. Each transformator receives the output of the previous one as input.
modules	No longer used.
is_transform_failed	No longer used.
expr	(expression or reactive) optional expression evaluated on top of the decorated output. Useful for post-processing after all transformators have run.
class	No longer used.
...	additional arguments passed to .ui_transform_teal_data (e.g. class).

Value

reactive teal_data

A list of bslib::accordion UI elements, one per transformator, or NULL if transformators is empty.

See Also

assert_decorators()

Examples

library(shiny)
library(teal.data)

# A decorator that sets a fixed title on a ggplot2 object named `plot`
static_decorator <- teal_transform_module(
  label = "Static decorator",
  server = function(id, data) {
    moduleServer(id, function(input, output, session) {
      reactive({
        req(data())
        within(data(), {
          plot <- plot + ggplot2::ggtitle("Decorated title")
        })
      })
    })
  }
)

if (interactive()) {
  shinyApp(
    ui = fluidPage(
      ui_transform_teal_data("decorate", transformators = list(static_decorator)),
      plotOutput("plot")
    ),
    server = function(input, output, session) {
      data <- reactive(
        teal_data(
          plot = ggplot2::ggplot(iris, ggplot2::aes(Sepal.Length, Sepal.Width)) +
            ggplot2::geom_point()
        )
      )
      decorated <- srv_transform_teal_data(
        "decorate",
        data = data,
        transformators = list(static_decorator)
      )
      output$plot <- renderPlot(decorated()[["plot"]])
    }
  )
}

teal documentation built on June 30, 2026, 5:11 p.m.