Problems using R shiny modules - r

I have just gotten into modules and it seems like I have not figured it out yet. The following code does not run properly. The app closes immediately after it opens.
It seems like the id does not match. However, I am not quite sure what goes wrong.
I set up input and output for the UI in the module and then set up the server for the module. I then combine everything in the UI and Server for the app and run it.
SharePrepayInputUI<- function(id, vChoice){
ns <- NS(id)
tagList(
fluidRow(
column(2,
pickerInput(ns("navn"),"Select Segment", choices=vChoice, options = list(
"actions-box" = TRUE,
"live-search" = TRUE),
multiple = TRUE))
)
)
}
ShareOutpuitUI <- function(id){
ns <- NS(id)
tagList(
fluidRow(
column(6,
dataTableOutput(ns("cls"))),
column(4,
dataTableOutput(ns("dbl")))
)
)
}
ShareServer <- function(id){
moduleServer(id, function(input, output, session){
# Table for cash loan share
output$cls <- renderDataTable({
DT::datatable(mCls[mCls$Segment %in% input$navn,], container = sketch_cls, rownames = FALSE)
})
output$dbl <- renderDataTable({
DT:datatable(mDbl[mDbl$Segment %in% input$navn,], container = sketch_dbl, rownmaes = FALSE)
})
})
}
UdtrDebUI <- fluidPage(
SharePrepayInputUI(id = "module_1", vChoice = mCls$Segment),
ShareOutpuitUI(id = "module_1")
)
UdtrDebServer <- function(id){
ShareServer(id = "module_1")
}
shinyApp(UdtrDebUI, UdtrDebServer)

Related

Dynamic UI/Server Modules in Shiny Dashboard Based on Inputs in UI

Let's say I have 4 sets of UI/Server modules in 4 different directories ("./X1/Y1/", "./X1/Y2/", "./X2/Y1/", "./X2/Y2/"). I want to load the selected set based on the input in the sidebar.
I tried using source() within dashboardBody(), but I was not successful.
library(shiny)
library(shinydashboard)
# path to modules
in_path <- "C:/a/b/c/"
# ui
ui <- dashboardPage(
dashboardHeader(title = "test"),
dashboardSidebar(
br(),
selectInput('f1', 'Folder 1', choices = c("X1", "X2")),
helpText(""),
selectInput('f2', 'Folder 2', choices = c("Y1", "Y2")),
br(),
actionButton("load", "Load", icon("thumbs-up"), width = "85%")
),
dashboardBody(
# UI module here from, e.g., "C:/a/b/c/X1/Y2/my_UI.R"
)
)
# server
server <- function(input, output, session) {
# server module here from, e.g., "C:/a/b/c/X1/Y2/my_Server.R"
}
shinyApp(ui, server)
As shiny modules are simply functions, I'd source them in the beginning, and use uiOutput to display the differnt modules.
Here's a working example of the general idea (sample module code proudly stolen from the official Shiny documentation):
<mod1.R>
counterButton <- function(id, label = "Counter") {
ns <- NS(id)
tagList(
actionButton(ns("button"), label = label),
verbatimTextOutput(ns("out"))
)
}
counterServer <- function(id) {
moduleServer(
id,
function(input, output, session) {
count <- reactiveVal(0)
observeEvent(input$button, {
count(count() + 1)
})
output$out <- renderText({
count()
})
count
}
)
}
<mod2.R>
csvFileUI <- function(id, label = "CSV file") {
ns <- NS(id)
tagList(
fileInput(ns("file"), label),
checkboxInput(ns("heading"), "Has heading"),
selectInput(ns("quote"), "Quote", c(
"None" = "",
"Double quote" = "\"",
"Single quote" = "'"
))
)
}
csvFileServer <- function(id, stringsAsFactors = TRUE) {
moduleServer(
id,
## Below is the module function
function(input, output, session) {
# The selected file, if any
userFile <- reactive({
# If no file is selected, don't do anything
validate(need(input$file, message = FALSE))
input$file
})
# The user's data, parsed into a data frame
dataframe <- reactive({
read.csv(userFile()$datapath,
header = input$heading,
quote = input$quote,
stringsAsFactors = stringsAsFactors)
})
# We can run observers in here if we want to
observe({
msg <- sprintf("File %s was uploaded", userFile()$name)
cat(msg, "\n")
})
# Return the reactive that yields the data frame
return(dataframe)
}
)
}
<app.R>
library(shiny)
source("mod1.R")
source("mod2.R")
my_mods <- list("Counter Button" = list(ui = counterButton,
server = counterServer),
"CSV Uploader" = list(ui = csvFileUI ,
server = csvFileServer))
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
selectInput("mod_sel",
"Which Module should be loaded?",
names(my_mods))
),
mainPanel(
uiOutput("content"),
verbatimTextOutput("out")
)
)
)
server <- function(input, output) {
uuid <- 1
handler <- reactiveVal()
output$content <- renderUI({
my_mods[[req(input$mod_sel)]]$ui(paste0("mod", uuid))
})
observeEvent(input$mod_sel, {
handler(my_mods[[req(input$mod_sel)]]$server(paste0("mod", uuid)))
uuid <<- uuid + 1
})
output$out <- renderPrint(req(handler())())
}
shinyApp(ui, server)
Some Explanation
You put the module code in mod[12].R and it is rather straight forward.
In your main app, you load both(!) source files and for housekeeping reasons, I put both modules functions (ui and server) in a list, but this is not strictly necessary, but facilitates future extension.
In your UI you have an uiOutput which renders dynamically according to the selected module.
In your server you put the code to dynamically render the UI and call the respective server function.
The uid construct is basically there to force a fresh render, whenever you change the selection. Otherwise, you may see still some old values whenever you come back to a module which you have rendered already.

Best practices for returning a server-side generated value from a Shiny module?

Consider the following example application:
library(shiny)
library(shinyWidgets)
module_UI <- function(id){
tagList(
div(
uiOutput(
outputId = NS(id, "selection")
),
shinyWidgets::dropdown(
uiOutput(outputId = NS(id, "new_option")),
style = "unite",
label = "New",
color = "primary",
animate = animateOptions(
enter = animations$fading_entrances$fadeInLeftBig,
exit = animations$fading_exits$fadeOutRightBig
),
up = F,
width = "600px",
inline = T
)
)
)
}
module_server <- function(id){
moduleServer(id, function(input, output, session){
ns <- session$ns
return_values <- reactiveValues(selection=NULL)
output$selection <- renderUI({
selectInput(inputId = ns("selection"), label = "Select:", choices = 1:5)
})
output$new_option <- renderUI({
div(
numericInput(ns("new_option_input"), label = "Add a new option:"),
shinyWidgets::actionBttn(
inputId = ns("submit_new_option"),
label = "Submit",
icon = icon("paper-plane"))
)
})
observeEvent(input$submit_new_option, {
#does not work as intended
updateSelectInput(session = session, inputId = "selection", selected = input$new_option_input)
})
observe({
return_values$selection <- input$selection
})
return(return_values)
})
}
# Define UI for application that draws a histogram
ui <- fluidPage(
title = "Test App",
module_UI("test"),
verbatimTextOutput(outputId = "selection_chosen")
)
# Define server logic required to draw a histogram
server <- function(input, output) {
picker <- module_server("test")
output$selection_chosen <- renderText({
picker$selection
})
}
# Run the application
shinyApp(ui = ui, server = server)
Basically, the module should do two things:
Allow user to select a pre-existing option --> return that value from module
Allow user to create their own, new option --> return that value from module
I have #1 working, but am struggling on #2. Specifically, where I have the "does not work" comment. How can I achieve this functionality? What are/is the best practice(s) for returning server-side created values from a Shiny module? This is an example app; the real one involves reading the selectInput options from a database, as well as saving the newly created options in the database. Appreciate any help on this! A lot of SO answers regarding Shiny modules have the older callModule(...) syntax, which makes researching this topic a bit more confusing.
You just need to provide the default value in numericInput. Perhaps you are looking for this.
library(shiny)
library(shinyWidgets)
module_UI <- function(id){
ns <- NS(id)
tagList(
div(
uiOutput(
outputId = NS(id, "selection")
),
shinyWidgets::dropdown(
uiOutput(outputId = NS(id, "new_option")),
style = "unite",
label = "New",
color = "primary",
animate = animateOptions(
enter = animations$fading_entrances$fadeInLeftBig,
exit = animations$fading_exits$fadeOutRightBig
),
up = F,
width = "600px",
inline = T
),
DTOutput(ns("t1"))
)
)
}
module_server <- function(id){
moduleServer(id, function(input, output, session){
ns <- session$ns
return_values <- reactiveValues(selection=NULL,myiris = iris)
output$selection <- renderUI({
selectInput(inputId = ns("selection"), label = "Select:", choices = 1:5)
})
output$new_option <- renderUI({
tagList(
numericInput(ns("new_option_input"), label = "Add a new option:",10, min = 1, max = 100),
shinyWidgets::actionBttn(
inputId = ns("submit_new_option"),
label = "Submit",
icon = icon("paper-plane"))
)
})
observeEvent(input$submit_new_option, {
return_values$myiris <- iris[1:input$new_option_input,]
#does work as intended
updateSelectInput(session = session, inputId = "selection", choices= c(1:input$new_option_input), selected = input$new_option_input)
})
output$t1 <- renderDT({return_values$myiris})
observe({
return_values$selection <- input$selection
})
return(return_values)
})
}
# Define UI for application that draws a histogram
ui <- fluidPage(
title = "Test App",
module_UI("test"),
verbatimTextOutput(outputId = "selection_chosen"),
DTOutput("t2")
)
# Define server logic required to draw a histogram
server <- function(input, output) {
picker <- module_server("test")
output$selection_chosen <- renderText({
picker$selection
})
output$t2 <- renderDT({picker$myiris[,c(3:5)]})
}
# Run the application
shinyApp(ui = ui, server = server)

How to dynamically update dropdown within a modulized shinyalert for each iteration of a for loop, when using html = TRUE?

I'm creating a shiny module, where I wish to display some pop-up messages to the user via shinyalerts and include dropdown menus via htlm = TRUE and shinyWidgets::pickerInput. For each shinyalert the options should be different and the alerts should appear right after each other when the user has selected the relevant option.
However, when running the shinyalerts within a for loop, only the first alert shows the drop-down, the following does not. Please have a look at the example below and screenshots. Any ideas what I'm doing wrong?
Module UI:
mod_match_columns_ui <- function(id){
ns <- NS(id)
tagList(
shinyalert::useShinyalert(),
actionButton(ns("run"), label = "Start!")
)
}
Module server:
mod_match_columns_server <- function(input, output, session){
ns <- session$ns
options <- list(c("option_1","option_2"),
c("option_3","option_4"))
observeEvent(input$run, {
for(col in 1:2){
nms <- options[[i]]
output[[paste0("dropdown",col)]] <- renderUI({
shinyWidgets::pickerInput(
inputId = ns(paste0("options",col)),
label = "Options listed below",
choices = nms,
selected = "",
multiple = FALSE,
options = shinyWidgets::pickerOptions(size = 15)
)
})
shinyalert::shinyalert(
title = "Pick an option!",
html = TRUE,
text = tagList(
uiOutput(ns(paste0("dropdown", col)))
),
inputId = ns(paste0("modal", col))
)
}
})
}
Run module:
library(shiny)
ui <- fluidPage(
mod_match_columns_ui("match_columns_ui_1")
)
server <- function(input, output, session) {
callModule(mod_match_columns_server, "match_columns_ui_1")
}
shinyApp(ui = ui, server = server)
First iteration:
Second iteration:
Why is the dropdown not shown in the second iteration?? Thanks
Try this
library(shiny)
library(shinyalert)
mod_match_columns_ui <- function(id){
ns <- NS(id)
tagList(
shinyalert::useShinyalert(),
actionButton(ns("run"), label = "Start!")
)
}
mod_match_columns_server <- function(id) {
moduleServer(id,
function(input, output, session) {
ns <- session$ns
options <- list(c("option_1","option_2"),
c("option_3","option_4"))
lapply(1:2, function(col){
output[[paste0("dropdown",col)]] <- renderUI({
shinyWidgets::pickerInput(
inputId = ns(paste0("options",col)),
label = paste("Options",col,"listed below"),
choices = options[[col]],
selected = "",
multiple = FALSE,
options = shinyWidgets::pickerOptions(size = 15)
)
})
})
observeEvent(input$run, {
shinyalert::shinyalert(
title = "Pick an option!",
html = TRUE,
text = tagList(
lapply(1:2, function(i){uiOutput(ns(paste0("dropdown",i)))})
)
# callbackR = function(x) { message("Hello ", x) },
# inputId = ns(paste0("modal"))
)
})
observe({
print(input$options1)
print(input$options2)
print(input$shinyalert)
})
})
}
ui <- fluidPage(
tagList(
mod_match_columns_ui("match_columns_ui_1")
)
)
server <- function(input, output, session) {
mod_match_columns_server("match_columns_ui_1")
}
shinyApp(ui = ui, server = server)

How do I convert this into a shiny module

Can you provide a MWE of modularized shiny code that uses renderUI? I'd like an example to follow.
There is an excellent tutorial that discusses this here: https://shiny.rstudio.com/articles/modules.html however, it doesn't show how to integrate the modularization of renderUI components in the ui nor in the server.
Here's what I've tried so far:
In my ui code, I had:
htmlOutput("selectionUI")
In my server code, I had:
output$selectionUI <- renderUI({
req(input$Filter)
selectInput(
inputId = "Selection",
label = "Selection",
choices = get("qlist", envir = get(input$source))[[input$Filter]]$responses)
})
Now I would like to modularize this becuase it's a sometimes repeated element, but I'm not sure how to actually insert it into my ui/server code once I'm done.
Here's what I've tried:
selectionChooserUI <- function(id) {
ns <- NS(id)
uiOutput(ns('controls'))
}
selectionChooser <- function(input, output, session, data, sourcedata, filter) {
output$selectionUI <- renderUI({
req(input$Filter)
ns <- session$ns
selectInput(
inputId = ns('Selection'),
label = 'Selection',
choices = get('qlist', envir = get(input[[sourcedata()]]))[[input[[filter()]]]]$responses
)
})
}
What do I have to put into my ui code to get it to diplay, currently I'm getting complaints that "output" is missing with no default?
I'm calling it presently in my ui code, using:
selectionChooserUI("selection")
It's probably something like this. I haven't test it out since I don't have your data ..
library(shiny)
ui <- fluidPage(
h1("Get me a Module!"),
selectInput("source", "Some source", choices = letters[1:4]),
selectInput("filter", "Some filter", choices = letters[1:4]),
selectionChooserUI("id_of_me")
)
server <- function(input, output, session) {
get_me_choices <- reactive({
get("qlist", envir = get(req(input$source)))[[req(input$filter)]]$responses })
callModule(module = selectionChooser, id = "id_of_me", choices = get_me_choices)
}
selectionChooserUI <- function(id) {
ns <- NS(id)
uiOutput(ns('selection'))
}
selectionChooser <- function(input, output, session, choices) {
ns <- session$ns
output$selection <- renderUI({
selectInput(
inputId = ns('selection'),
label = 'Selection',
choices = choices
)
})
}

lapply modules and make use of reactive return from shiny modules

I have created a sample app below to illustrate the issue I am having. I have an application in Shiny that is using many layers of modules. I am very familiar with using modules and returning reactive values from the modules themselves. However when I need to use lapply to create multiple calls of modules (in this case slider_menu_item_shiny function to create multiple sliders), each which return the reactive value that is set by the user in sliders, I am not sure how to dynamically capture all of the output reactive variables into one reactive vector.
Right now I have 2 sliders hard coded in and this simple app works. However I want to be able to type in an arbitrary value in the first input, have the app create that amount of slider modules using the lapply statement (for the callModule(slider_menu_item_shiny) call too) and then have slider_value_vector contain a vector of that length with all of the slider values.
I feel like I am missing a fundamental trick to making this work. I would really appreciate the learning experience and all of the help.
ui.R code
library(shiny)
library(shinydashboard)
library(DT)
#### MODULE CODE ####
source("modules.R")
# define header
header <- dashboardHeader(
title = "Test"
)
# define body
body <- dashboardBody(
tabItems(
body_set_shinyUI(id = "body_test_mod", tab_name = "body_test_mod")
)
)
# define sidebar
sidebar <- dashboardSidebar(
sidebarMenu(id = "dashboard_menu",
menuItem("Test Body", tabName = "body_test_mod")
)
)
dashboardPage(skin = "blue",
header,
sidebar,
body
)
server.R code
library(shiny)
library(shinydashboard)
library(DT)
#### MODULE CODE ####
source("modules.R")
#### SERVER CODE ####
function(input, output, session) {
callModule(body_set_shiny, id = "body_test_mod")
}
modules.R code
### body_set_shiny
body_set_shinyUI <- function(id, tab_name) {
ns <- NS(id)
tabItem(tabName = tab_name,
fluidRow(
column(12,
inner_body_test_menu_shinyUI(ns("inner_body_test_mod"))
)
)
)
}
body_set_shiny <- function(input, output, session) {
callModule(inner_body_test_menu_shiny, id = "inner_body_test_mod")
}
### inner_body_test_menu_shiny
inner_body_test_menu_shinyUI <- function(id) {
ns <- NS(id)
fluidRow(
column(12,
box(title = "Test Inner Menu",
width = 12,
fluidRow(
column(12,
wellPanel(
uiOutput(ns("inner_number_menu")),
uiOutput(ns("inner_sliders_menu")),
uiOutput(ns("inner_text_output"))
)
)
)
)
)
)
}
inner_body_test_menu_shiny <- function(input, output, session) {
output$inner_number_menu <- renderUI({
ns <- session$ns
textInput(ns("inner_number_value"), label = "Enter Number of Sliders", value = "2")
})
slider_length <- reactive({
if (is.null(input$inner_number_value))
return()
as.numeric(input$inner_number_value)
})
output$inner_sliders_menu <- renderUI({
if (is.null(slider_length()))
return()
ns <- session$ns
lapply((1:slider_length()), function(m) {
slider_menu_item_shinyUI(ns(paste("slider_menu_item_", m, sep = "")))
})
})
output$inner_text_output <- renderText({
if (is.null(slider_value_vector()))
return()
paste("You have entered", slider_value_vector())
})
slider_value_vector <- reactive({
if (is.null(slider_length()))
return()
c(as.numeric(slider_v1()[[1]]),as.numeric(slider_v2()[[1]]))
})
slider_v1 <- callModule(slider_menu_item_shiny, paste("slider_menu_item_", 1, sep = ""))
slider_v2 <- callModule(slider_menu_item_shiny, paste("slider_menu_item_", 2, sep = ""))
}
slider_menu_item_shinyUI <- function(id) {
ns <- NS(id)
uiOutput(ns('sider_output_menu'))
}
slider_menu_item_shiny <- function(input, output, session, slider_value = 0, slider_name = "No Name Found") {
output$sider_output_menu <- renderUI({
ns <- session$ns
uiOutput(ns("slider_item_menu"))
})
output$slider_item_menu <- renderUI({
ns <- session$ns
sliderInput(ns("slider_item"), label = "Slider Example", min = -1, max = 1, value = 0.5, step = 0.01)
})
return(reactive(list(input$slider_item)))
}

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