reset handsontable values in Shiny app

Question

I'm building a data entry form with a handsontable using Shiny and the rhandsontable package. I've gotten the table and all other fields up and running, but I'd like to reset the user-entered values in the handsontable after the user clicks a submit button so that they can enter another response on a fresh form. I've tried the few solutions that I could find on github but none seemed to work for my data... they all still left the old values after hitting the submit button.

Here's a version of the app (with data saving and database connection removed)

    library(shiny)
library(rhandsontable)

# which fields get saved 
fieldsAll <- c("name", "alt_name", "taxonomy", "distribution", "disease", "host", "substrate", "other")

# which fields are mandatory
fieldsMandatory <- c("name")

# add an asterisk to an input label
labelMandatory <- function(label) {
  tagList(
    label,
    span("*", class = "mandatory_star")
  )
}

########APP#############
ui = fluidPage(
  shinyjs::useShinyjs(),

  div(id = "header",
      h1("Data entry")
      ),

  fluidRow(
    column(4,
           div(
             id = "form",
             helpText(h4("Nomenclature")),
             textInput("name", labelMandatory("Scientific Name"), ""),
             textInput("alt_name", "Comma separated alternative names(s)", ""),
             br(),
             br(),
             helpText(h4("Basic Data")),
             textInput("taxonomy", "GBIF ID (or other taxonomy database link)", ""),
             textInput("distribution", "Distribution (Eg. North America)", ""),
             textInput("disease", "Disease Type (eg. vascular wilt)", ""),
             textInput("host", "Common Hosts (eg. poaceae, confiers, etc.)", ""),
             textInput("substrate", "Common Substrates(s) (eg. infloresence)", ""),
             textInput("other", "Other Data", ""),
             br(),
             br(),
             helpText(h4("Submission")),
             helpText("Please double check that all info is correct before submitting"),
             actionButton("submit", "Submit", class = "btn-primary"),

             shinyjs::hidden(
               span(id = "submit_msg", "Submitting..."),
               div(id = "error",
                   div(br(), tags$b("Error: "), span(id = "error_msg"))
               )
             )
           ),

           shinyjs::hidden(
             div(
               id = "thankyou_msg",
               h3("Thanks, your response was submitted successfully!"),
               actionLink("submit_another", "Submit another response")
             )
           )
    ),
    column(8,
           div(
             id = "form2",

             rHandsontableOutput("hot", width = 1000, height = 600),

             shinyjs::hidden(
               span(id = "submit_msg", "Submitting..."),
               div(id = "error",
                   div(br(), tags$b("Error: "), span(id = "error_msg"))
               )
             )
    )
           )
    )
  )


server <- function(input, output, session) {
  # Enable the Submit button when all mandatory fields are filled out
  observe({
    mandatoryFilled <-
      vapply(fieldsMandatory,
             function(x) {
               !is.null(input[[x]]) && input[[x]] != ""
             },
             logical(1))
    mandatoryFilled <- all(mandatoryFilled)

    shinyjs::toggleState(id = "submit", condition = mandatoryFilled)
  })

  #handsontable for input values
  values = reactiveValues(DF = data.frame(location = rep("place name", 5), dates = rep("YYYY", 5), hosts = rep("host", 5),
                                          references = rep("ref", 5),
                                          stringsAsFactors = F))

  locations_table = reactive({
    if (!is.null(input$hot)) {
      DF = hot_to_r(input$hot)
    } else {
      DF = values$DF
    }
    values$DF = DF
    DF
  })

  output$hot <- renderRHandsontable({
    DF = locations_table()
    if (!is.null(DF))
      rhandsontable(DF, useTypes = F, stretchH = "all")
  })

  # When the Submit button is clicked, submit the response
  observeEvent(input$submit, {

    # User-experience stuff
    shinyjs::disable("submit")
    shinyjs::show("submit_msg")
    shinyjs::hide("error")

    # Save the data (show an error message in case of error)
    tryCatch({
      shinyjs::reset("form")
      shinyjs::hide("form")
      shinyjs::reset("form2")
      shinyjs::hide("form2")
      shinyjs::show("thankyou_msg")
    },
    error = function(err) {
      shinyjs::html("error_msg", err$message)
      shinyjs::show(id = "error", anim = TRUE, animType = "fade")
    },
    finally = {
      shinyjs::enable("submit")
      shinyjs::hide("submit_msg")
    })
  })

  # submit another response
  observeEvent(input$submit_another, {
    shinyjs::show("form")
    shinyjs::show("form2")
    shinyjs::hide("thankyou_msg")
  })

}

# Run the application 
shinyApp(ui = ui, server = server)

Simon.S.A. Simon.S.A. · Accepted Answer · 2018-08-29T03:40:49

You appear to be using textInput widgets to collect user input. Hence you can change these in your button observation event using updateTextInput.

In fact you should find that every shiny widget has an update function that lets you do a similar thing.

reset handsontable values in Shiny app

1 Answers