R/startRec.R

In abbey-thomas/speechcollectr: R Tools for Collecting Speech Production & Perception Data

#' Start Recording User Audio in a Shiny App
#'
#' @description Requests access to the user's microphone and begins audio recording if permission is granted. For use only inside a call to `observeEvent()` or `bindEvent()` in a Shiny application's server code.
#' @param readyId Character string. An input Id to be added to the input object when the user grants access to the microphone. Defaults to "rec-ready".
#' @return Adds an object with the inputId given as value of the readyId argument to the session's input object when the user grants microphone access or when access is confirmed. This event can be used to trigger other actions (like the appearance of some text for the participant to read).
#' @export
#' @seealso Should be used with \code{\link{stopRec}}
#'
#' @examples
#' if (interactive()){
#'  library(shiny)
#'  library(shinyjs)
#'
#'  # Build UI
#'  ui <- fluidPage(
#'
#'    ## Get background javascript ready
#'    useShinyjs(),
#'    tags$head(
#'      useRecorder()
#'    ),
#'
#'    ## Setup page layout
#'    div(id = "trialDiv",
#'        style = "text-align:center;",
#'
#'        hidden(div(id = "textDiv",
#'                   h4("Please record yourself reading this sentence aloud:"),
#'                   h2(textOutput(outputId = "read_this")))),
#'
#'        ## Create the buttons for controlling the recording
#'        actionButton(inputId = "start",
#'                     label = "start"),
#'
#'        ### Hide the stop button until user clicks start
#'        hidden(actionButton(inputId = "stop",
#'                            label = "stop")),
#'        textOutput(outputId = "file_saved")
#'    )
#'  )
#'
#'  # The Server function
#'  server <- function(input, output, session) {
#'    ## Create an object that will count trials
#'    rvs <- reactiveValues(trial_n = 0)
#'
#'    ## When the start button is clicked
#'    observeEvent(input$start, {
#'
#'      ### Increase counter by one
#'      rvs$trial_n <- rvs$trial_n + 1
#'
#'      ### Start the recording
#'      startRec(readyId = "ready")
#'
#'      ### Disable the start button
#'      disable("start")
#'
#'      ### Show the stop button
#'      delay(500, showElement("stop"))
#'    })
#'
#'    observeEvent(input$ready, {
#'      showElement("textDiv")
#'      output$read_this <- renderText({paste0("This is recording ",
#'                                             rvs$trial_n, ".")})
#'    })
#'
#'    ## When the user clicks stop
#'    observeEvent(input$stop, {
#'
#'      ### Stop recording
#'      stopRec(filename = paste0("rec", rvs$trial_n, ".wav"),
#'              finishedId = "done")
#'
#'      ### Enable the start button
#'      enable("start")
#'
#'      ### Hide the stop button
#'      hide("stop")
#'      hide("textDiv")
#'    })
#'
#'    observeEvent(input$done, {
#'      output$file_saved <- renderText({paste0("The file ", input$done, " was saved.")})
#'    })
#'  }
#'
#'  # Run the application
#'  shinyApp(ui = ui, server = server)
#' }
#'
startRec <- function(readyId = "rec-ready") {
  session <- shiny::getDefaultReactiveDomain()
  el <- paste0(readyId)
  session$sendCustomMessage("startRec", el)
}