updatePickerInput after updateTabItem call in modularized R Shiny App

Question

Goal:

I would like to select a row in the DT Table, switch tabs, and have the pickerInput value update to the value in the table's row.

Issue:

I am able to switch tabs just fine (thanks to another post's advice on using the parent session); however, I cannot seem to figure out how to get the updatePickerInput to work properly. I believe there is an issue in the session and inputId arguments. It would make sense that the session for the updatePickerInput would not be the parent session but more like the "child" session from the updateTabItem call.

Reprex:

Below is a single file app.r script that has the two panels' modules as global functions.

sessionInfo():

R version 4.0.3 (2020-10-10)

Platform: x86_64-apple-darwin17.0 (64-bit)

Running under: macOS Big Sur 10.16

# Dependencies ----
library(shiny)
library(shinydashboard)
library(shinyWidgets)
library(dplyr)
library(DT)

# Picker Module ----
# Picker UI
picker_ui <- function(id){
    box(width = 12
        , uiOutput(NS(id, "picker"))
    )
}
# Picker Server
picker_server <- function(id){
    moduleServer(id, function(input, output, session){
        # render pickerInput
        output$picker <- renderUI({
            ls_choices <- c("One", "Two", "Three")
            pickerInput(NS(id, "pickerInput")
                        , choices = ls_choices
                        , selected = NULL)
        })
    })
}

# Table Module ----
# Table UI
table_ui <- function(id){
    fluidPage(
        box(width  = 12
            , DTOutput(NS(id, "table"))
        )
    )
}
# Table Server
table_server <- function(id, parent){
    moduleServer(id, function(input, output, session){
        output$table <- renderDT({
            data <- c("One", "Two", "Three")
            df <- tibble("Labels" = data)
            datatable(df, rownames = F, selection = "single", options = list(dom = 'tip'))
        })
        observeEvent(input$table_cell_clicked, {
            req(input$table_cell_clicked$value)
            updateTabItems(session = parent, inputId = "tabs", selected = "picker")
            ################
            #### ISSUE #####
            ################
            updatePickerInput(session = session, inputId = "pickerInput", selected =  input$table_cell_clicked$value)
        })
    }) 
}

# Shiny App----
# UI
ui <- dashboardPage(
    dashboardHeader(title = "Demo")
    , dashboardSidebar(
        sidebarMenu(
            id = "tabs"
            , menuItem("Table", tabName = "table")
            , menuItem("Picker Input", tabName = "picker")
        )
    )
    , dashboardBody(
        tabItems(
            tabItem(tabName = "table"
                    , table_ui("table")
            )
            , tabItem(tabName = "picker"
                      , picker_ui("picker")
            )
        )
    )
)

# Server
server <- function(input, output, session) {
    table_server("table", session)
    picker_server("picker")
}

# Run App ----
shinyApp(ui, server)

score 1 · Accepted Answer · answered Feb 26 '21 at 01:27

You're trying to use table module session to update the picker (which is actually in picker module session)

Return the picker module session from the picker moduleServer:

# Picker Server
picker_server <- function(id){
  moduleServer(id, function(input, output, session){
    # render pickerInput
    output$picker <- renderUI({
      ls_choices <- c("One", "Two", "Three")
      pickerInput(NS(id, "pickerInput")
                  , choices = ls_choices
                  , selected = NULL)
    })
    return(session)
  })
}

Get it in the app server and pass it to the table module:

# Server
server <- function(input, output, session) {
  picker_session = picker_server("picker")
  table_server("table", session, picker_session)
}

Use it in the table module to update the picker

# Table Server
table_server <- function(id, parent, picker_session){
  moduleServer(id, function(input, output, session){
    output$table <- renderDT({
      data <- c("One", "Two", "Three")
      df <- tibble("Labels" = data)
      datatable(df, rownames = F, selection = "single", options = list(dom = 'tip'))
    })
    observeEvent(input$table_cell_clicked, {
      req(input$table_cell_clicked$value)
      updateTabItems(session = parent, inputId = "tabs", selected = "picker")
      ################
      #### ISSUE #####
      ################
      updatePickerInput(session = picker_session, inputId = "pickerInput", selected =  input$table_cell_clicked$value)
    })
  }) 
}

Thank you for your response! I have found one further issue in that when the table value is initially clicked (before going to the drop down panel) that it does not edit the first time. — Owen Bezick, Feb 27 '21 at 13:10
I have noticed same issue. I initially debugged your app using `selectInput` instead of `pickerInput` and it worked fine. — HubertL, Feb 27 '21 at 20:05
Ah, will try that! The work around I came to was sending a reactiveValues container with the value to update the picker to and a flag of whether or not it was coming from a tab switch. Then on instantiation of the picker, if the flag was true, it selected the value. If not, it instantiated as normal. Then I put an observer in the server that if the flag was true, it would update the picker to the value in the reactive container. Thank you for your help, though! — Owen Bezick, Feb 28 '21 at 21:37

updatePickerInput after updateTabItem call in modularized R Shiny App

1 Answers1