Register output and output options — register

Enable advanced output gadgets such as expanding the output in another browser window, or downloading the rendered data.

Usage

register_output_options(
  outputId,
  ...,
  .opt = list(),
  extras = list(),
  session = shiny::getDefaultReactiveDomain()
)

get_output_options(outputId, session = shiny::getDefaultReactiveDomain())

register_output(
  render_function,
  outputId,
  ...,
  output_opts = list(),
  quoted = FALSE,
  download_function = NULL,
  download_fileformat =
    "{ outputId }-{ format(Sys.time(), '%b_%d_%Y_%H_%M_%S') }.{ extension }",
  output_type = c("image", "data", "threeBrain", "no-download"),
  extensions = NULL,
  title = "Download widget",
  cancel_btn = "Cancel",
  confirm_btn = "Download",
  session = shiny::getDefaultReactiveDomain()
)

get_output(outputId, session = shiny::getDefaultReactiveDomain())

Arguments

outputId: output ID in the scope of current shiny session
extras: extra information to store
session: shiny session instance
render_function: shiny render function
output_opts, .opt: output options
quoted: whether render_function is quoted; default is false
download_function: core function that writes the data into the files; default is set for 'image' and 'threeBrain' automatically; see 'Default' and 'Examples'.
download_fileformat: download file format, supports 'glue'
output_type: type of export file formats supported, options are 'image' (for figures, default), 'data', 'threeBrain' (for 'RAVE' 3D viewers), and 'no-download' (do not export).
extensions: a list of file extensions and their descriptions; the names will be used to display the modal selectors, and values are the underlying extension read by download_fileformat
title, cancel_btn, confirm_btn, ...: title, button labels, and additional 'HTML' elements that are to be shown in the modal

Value

Registered output or output options.

Details

The following steps are done when register_output is called:

* Register the render function to shiny output output[[outputId]] * Register the render information to session which can be retrieved via get_output * Register (if download_function is a function) a download handler that listen to the shiny event. The event ID is paste0(outputId, '__download2').

When downloading event is triggered, a modal will pop up asking for exporting format (always exists) and image dimensions (if output type is 'image') or title (when output type is 'threeBrain'). Users will choose the proper inputs, which will be passed into download_function.

The file extensions is a named list. Its names are printable descriptions of the formats, and values are the file extensions (without the leading '.'). for example, list("compressed CSV" = "csv"). Users will see "compressed CSV" in the format selector, and download_function sees "csv".

When output type is image, users will be asked to enter the image size in inches; default width is 7, and height is calculated based on current image aspect ratio.

If you would like to show more on the modal, pass 'HTML' elements to ...

Function download_function is a function containing four inputs:

* con: file where the data should be written into * params: a named list of params$extension (file extension), width, height (type is image), or title (3D viewer) * render_expr a quoted rendering expression of the rendering function * render_env the rendering environment of the rendering function.

Default download_function is provided when not specified.

Examples



if(interactive()) {

library(shiny)
library(ravedash)

# ---- Use this in RAVE --------

# UI
output_gadget_container(
  plotOutput("plot", brush = shiny::brushOpts("plot__brush")),
)

# server
server <- function(input, output, session) {
  register_output(
    renderPlot({
      # ... plot it
    }),
    outputId = "plot",
    output_opts = list(brush = shiny::brushOpts("plot__brush"))
  )
}


# ---- Low-level method ------------

rave_id <- paste(sample(c(letters, LETTERS, 0:9), 20, replace = TRUE),
                 collapse = "")

ui <- function(req) {
  query_string <- req$QUERY_STRING
  if(length(query_string) != 1) {
    query_string <- "/"
  }
  query_result <- httr::parse_url(query_string)

  if(!identical(toupper(query_result$query$standalone), "TRUE")) {
    # normal page
    basicPage(
      output_gadget_container(
        plotOutput("plot", brush = shiny::brushOpts("plot__brush")),
      )
    )
  } else {
    # standalone viewer
    uiOutput("viewer")
  }
}

server <- function(input, output, session) {

  bindEvent(
    safe_observe({
      query_string <- session$clientData$url_search
      query_result <- httr::parse_url(query_string)

      if(!identical(toupper(query_result$query$module), "standalone_viewer")) {
        # normal page
        register_rave_session(session = session, .rave_id = rave_id)
        register_output(
          renderPlot({
            input$btn
            plot(rnorm(100), pch = 16)
          }),
          outputId = "plot",
          output_opts = list(brush = shiny::brushOpts("plot__brush"))
        )
      } else {
        # standalone viewer
        standalone_viewer(outputId = "plot", rave_id = rave_id)
      }
    }),
    session$clientData$url_search
  )


}

shinyApp(ui, server, options = list(port = 8989))
}