Communication between modules and looping through values to create several modules - r

Goal
I have five expectations:
Solution using modules
Communication between modules
Dynamic creation of modules
local storage using shinyStore
Export result in dataframe
What has worked so far
This is a continuation of the following question.
I have a Shiny app that currently has two modules, but I have had issues with both of them communicating. The first module Selects any number of species within a Species pool (SpeciesSelect), this module is in the file R/SpeciesSelect.R within my working directory with the following code.
SpeciesSelect_UI <- function(id, SpeciesList){
ns <- NS(id)
tagList(
shiny::selectizeInput(inputId = ns("SpeciesNames"), label = "SpeciesName",
choices = SpeciesList,
multiple = T)
)
}
SpeciesSelect_Server <- function(id){
moduleServer(id, function(input, output, session) {
# return the reactive here
return(reactive({input$SpeciesNames}))
})
}
And the second module (SpeciesCount) would use those species in order to select how you sample them, and in some cases to count them when the method is equal to pinpoint. This is stored in R/SpeciesCount.R and the code is as follows:
SpeciesCount_UI <- function(id, Species){
ns <- NS(id)
tagList(
shinyMobile::f7Card(
f7Flex(
textOutput(ns("SpeciesAgain")),
uiOutput(ns("Sampling_type_ui")),
uiOutput(ns("SpeciesCount"))
)
)
)
}
SpeciesCount_Server <- function(id, Species){
moduleServer(id, function(input, output, session) {
output$SpeciesAgain <- renderText({Species})
ns <- session$ns
output$Sampling_type_ui <- renderUI({
#req(input$SpeciesName)
req(Species)
f7Select(inputId = ns("Sampling_type"),
label = "Sampling type",
choices = c("5m circle", "15m circle", "Pin-point"))
})
output$SpeciesCount <- renderUI({
if (req(input$Sampling_type) == "Pin-point") {
shinyMobile::f7Stepper(inputId = ns("Species1"), label = "Species count", min = 1, max = 1000, step = 1, value = 1)
}
})
})
}
Each of the modules is working well on its own as shown in the following example:
library(shiny)
library(shinyMobile)
library(shinyStore)
source("R/SpeciesCount.R")
source("R/SpeciesSelect.R")
SpeciesList <- c("Species1", "Species2", "Species3", "Species4", "Species5")
ui = f7Page(
title = "Show navbar",
f7SingleLayout(
navbar = f7Navbar("Hide/Show navbar"),
f7Button(inputId = "toggle", "Toggle navbar", color = "red"),
SpeciesSelect_UI(id = "SpeciesList", SpeciesList = SpeciesList),
lapply(seq_along(SpeciesList), function(i) {
SpeciesCount_UI(id = i, Species = SpeciesList[i])
})
)
)
server = function(input, output, session) {
lapply(seq_along(SpeciesList), function(i) {
SpeciesCount_Server(id = i, Species = SpeciesList[i])
})
observeEvent(input$toggle, {
updateF7Navbar()
})
}
shinyApp(ui, server)
I have 4 issues that are not working well, first, the communication between modules, and then looping through the results of the first module to get several of the second module, the localStorage issue, and finally exporting it to a dataframe
Communication between modules and dynamic UI generation
In order to isolate both issues, for the communication problem, I selected only one species and took out the lapply function to see if I can get the SpeciesCount to recognise the output of the SpeciesSelect_Server and incorporate it into the SpeciesCount module, here is the code I ended up with:
library(shiny)
library(shinyMobile)
library(shinyStore)
source("R/SpeciesCount.R")
source("R/SpeciesSelect.R")
LIST <- c("Species1", "Species2", "Species3", "Species4", "Species5")
ui = f7Page(
title = "Show navbar",
f7SingleLayout(
navbar = f7Navbar("Hide/Show navbar"),
f7Button(inputId = "toggle", "Toggle navbar", color = "red"),
SpeciesSelect_UI(id = "SpeciesList", SpeciesList = LIST),
SpeciesCount_UI(id = "SpeciesCount", Species = SpeciesSelected())
)
)
server = function(input, output, session) {
SpeciesSelected <- SpeciesSelect_Server(id = "SpeciesList")
SpeciesCount_Server(id = "SpeciesCount", Species = SpeciesSelected())
observeEvent(input$toggle, {
updateF7Navbar()
})
}
shinyApp(ui, server)
But the results of the SpeciesSelect module are not generating any UI in the SpeciesCount module
Adding the LocalStorage issue
This app is going to be used in the field, that means, that at time we might get connectivity issues, I have issues at storing the values of the Species Select Module, then for sure I will have issues with the next module this is the shiny app I am using
library(shiny)
library(shinyMobile)
library(shinyStore)
source("R/SpeciesCount.R")
source("R/SpeciesSelect.R")
SpeciesList <- c("Species1", "Species2", "Species3", "Species4", "Species5")
ui = f7Page(
title = "Show navbar",
f7SingleLayout(
navbar = f7Navbar("Hide/Show navbar"),
f7Button(inputId = "toggle", "Toggle navbar", color = "red"),
SpeciesSelect_UI(id = "SpeciesList", SpeciesList = SpeciesList),
lapply(seq_along(SpeciesList), function(i) {
SpeciesCount_UI(id = i, Species = SpeciesList[i])
})
)
)
server = function(input, output, session) {
lapply(seq_along(SpeciesList), function(i) {
SpeciesCount_Server(id = i, Species = SpeciesList[i])
})
observeEvent(input$toggle, {
updateF7Navbar()
})
}
shinyApp(ui, server)
And I modified the species select for that also
SpeciesSelect_UI <- function(id, SpeciesList){
ns <- NS(id)
tagList(
shiny::selectizeInput(inputId = ns("SpeciesNames"), label = "SpeciesName",
choices = SpeciesList,
multiple = T)
)
}
SpeciesSelect_Server <- function(id){
moduleServer(id, function(input, output, session) {
ns <- session$ns
# return the reactive here
observeEvent(input$save, {
updateStore(session, name = ns("SpeciesNames"), input$SpeciesNames)
}, ignoreInit = TRUE)
observeEvent(input$clear, {
# clear current user inputs:
updateTextInput(session, inputId = ns("SpeciesNames"), value = "")
# clear shinyStore:
updateStore(session, name = ns("SpeciesNames"), value = "")
}, ignoreInit = TRUE)
return(reactive({ns(input$SpeciesNames)}))
})
}
But nothing gets stored. Maybe creating a module for shiny store is needed?
Export as a dataframe
This one is tied two point 2:
So lets say I am in the following input set:
The idea would be to generate a reactive that has the following that frame, that I can then export as a CSV file. I think I can handle the export, but I am unsure on how to generate the data.frame from the dynamic UI:
data.frame(Species = c("Species1", "Species2", "Species3"), Method = c("Pin-point","5m circle", "15m circle"), abundance = c(5, 1, 1))

Your first module is probably already silently returning the reactive but for clarity you can make it explicit. In you first module, return a reactive:
SpeciesSelect_Server <- function(id){
moduleServer(id, function(input, output, session) {
# return the reactive here
return(reactive({input$SpeciesNames}))
})
}
Now call the module AND assign its output a name where you'd like to use it (in another module or in your app server), like this:
selected_species <- SpeciesSelect_Server(id = "SpeciesList")
Now selected_species can be called, observed, etc with:
selected_species()

Related

R Shiny - Saving results of dynamically created modules

I encountered the following problem that I have tried to summarize in this minimal reproducible example.
The app should be able to dynamically create modules and render the UI of the module - obj_UI in my example - in a tab of the tabsetpanel objTP. Each of this modules should render a R6 object of type objR6. I would like to save the resulting R6 objects into a reactiveValues variable called objCollection and display it in the verbatimTextOutput called displayValues.
When clicking on the input$addObject button, I get the error message "Error in <-: cannot add bindings to a locked environment". I believe the problem lies in the observeEvent at the very end of the example, but cannot figure what it is.
Any help would be much appreciated!
library(shiny)
library(R6)
# Simple R6 object
objR6 <- R6::R6Class(
"objR6",
public = list(
identifier = NULL,
selected_value = NULL,
initialize = function(identifier) {
self$identifier <- identifier
}
)
)
# Module Ui
obj_UI <- function(id) {
tagList(
selectInput(NS(id, "value"), "Chose Value", letters)
)
}
# Module Server
obj_Server <- function(id) {
moduleServer(id, function(input, output, session) {
obj <- reactiveVal(objR6$new(id))
observeEvent(input$value, {
newObj <- obj()$clone()
newObj$selectec_value <- input$value
obj(newObj)
})
return(reactive(obj()))
})
}
# Shiny App
ui <- fluidPage(
fluidPage(
selectInput("objSelection", "Select Object",
choices = "",
selectize = FALSE,
size = 10),
actionButton("addObject", "Add Object"),
actionButton("rmvObject", "Remove Object"),
tabsetPanel(id = "objTP"),
verbatimTextOutput("displayValues")
)
)
server <- function(input, output, session) {
objCount <- reactiveVal(0)
objCollection <- reactiveValues(objects = list())
# Reaction on action button "addObject"
observeEvent(input$addObject, {
# Add another item
objCount(objCount() + 1)
newObjName <- paste0("Object_", objCount())
updateSelectInput(session, "objSelection", choices = c(paste0("Object_", 1:objCount())))
# Append the object tabset panel
appendTab("objTP", tabPanel(newObjName, obj_UI(newObjName)), select = TRUE)
})
# Reaction on action button "rmvObject"
observeEvent(input$rmvObject, {
delObjName <- paste0("Object_", objCount())
objCount(objCount() - 1)
updateSelectInput(session, "objSelection", choices = c(paste0("Object_", 1:objCount())))
removeTab("objTP", target = delObjName)
})
# Implement the server side of module
observeEvent(objCount(), {
if (objCount() > 0) {
for (i in 1:objCount()) {
identifier <- paste0("Object_", i)
observeEvent(obj_Server(identifier), {
objCollection$objects[[identifier]] <- obj_Server(identifier)
})
}
}
# Ouput the selected values
output$displayValues <- renderPrint({
reactiveValuesToList(objCollection)
})
})
}
shinyApp(ui, server)
The following minimal reproducible example is an answer to the problem above. In comparison to the code above I corrected a typo in the server function of the module and also put the initialization of the server part in the observeEvent for the input$addObject and removed the observeEvent for objCount().
library(shiny)
library(R6)
# Simple R6 object
objR6 <- R6::R6Class(
"objR6",
public = list(
identifier = NULL,
selected_value = NULL,
initialize = function(identifier) {
self$identifier <- identifier
}
)
)
# Module Ui
obj_UI <- function(id) {
tagList(
selectInput(NS(id, "value"), "Chose Value", letters)
)
}
# Module Server
obj_Server <- function(id) {
moduleServer(id, function(input, output, session) {
obj <- reactiveVal(objR6$new(id))
observeEvent(input$value, {
newObj <- obj()$clone()
newObj$selected_value <- input$value
obj(newObj)
})
return(reactive(obj()))
})
}
# Shiny App
ui <- fluidPage(
fluidPage(
selectInput("objSelection", "Select Object",
choices = "",
selectize = FALSE,
size = 10),
actionButton("addObject", "Add Object"),
actionButton("rmvObject", "Remove Object"),
tabsetPanel(id = "objTP"),
verbatimTextOutput("displayValues")
)
)
server <- function(input, output, session) {
objCount <- reactiveVal(0)
objCollection <- reactiveValues(objects = list())
# Reaction on action button "addObject"
observeEvent(input$addObject, {
# Add another item
objCount(objCount() + 1)
newObjName <- paste0("Object_", objCount())
updateSelectInput(session, "objSelection", choices = c(paste0("Object_", 1:objCount())))
# Append the object tabset panel
appendTab("objTP", tabPanel(newObjName, obj_UI(newObjName)), select = TRUE)
# Add the server component of the module
observeEvent(obj_Server(newObjName), {
objCollection$objects[[newObjName]] <- obj_Server(newObjName)
})
})
# Reaction on action button "rmvObject"
observeEvent(input$rmvObject, {
delObjName <- paste0("Object_", objCount())
if (objCount() > 0) {
objCount(objCount() - 1)
removeTab("objTP", target = delObjName)
objCollection$objects[[delObjName]] <- NULL
if (objCount() > 0) {
updateSelectInput(session, "objSelection", choices = c(paste0("Object_", 1:objCount())))
} else {
updateSelectInput(session, "objSelection", choices = "")
}
}
})
# Ouput the selected values
output$displayValues <- renderPrint({
lapply(reactiveValuesToList(objCollection)$objects, function(i) {i()})
})
}
shinyApp(ui, server)

R shiny: save data frames from multiple panels

In the following app, I would like to add a global button, to save the tables in the 2 panels at the same time.
Ideally, they should be saved to an xlsx file, in tabs named after the corresponding tabs.
Please note that the tabs were created using a module.
Many thanks!!
library(shiny)
library(DT)
modDtUi <- function(id){ # UI module
ns = NS(id)
DT::dataTableOutput(ns('x1'))
}
modDt <- function(input, output, session, data, globalSession){ # Server module
x <- data
output$x1 <- DT::renderDataTable(x, selection = 'none', editable = TRUE)
proxy <- dataTableProxy('x1', session = globalSession)
}
ui <- fluidPage(
mainPanel(
tabsetPanel(
tabPanel("Table1", modDtUi("editable")),
tabPanel("Table2", modDtUi("editable2"))
)
)
)
server <- function(input, output, session) {
callModule(modDt,"editable", data = head(iris,10), globalSession = session)
callModule(modDt,"editable2", data = tail(iris,5), globalSession = session)
}
shinyApp(ui = ui, server = server)
I believe this demo works.
I used reactiveValues v$data to store the data inside the module. The module will return v$data so it can be retrieved when you want to save the data in the shiny server.
I also added an observeEvent to detect changes in the data, and update the data table with replaceData.
The excel file is created using the writexl library, but you could substitute with others of course.
Let me know if this works for you. I imagine there are some elements of this answer that can be improved upon - and if we can identify them, would like to edit further.
library(shiny)
library(DT)
library(writexl)
modDtUi <- function(id){ # UI module
ns = NS(id)
DT::dataTableOutput(ns(id))
}
modDt <- function(input, output, session, data, id, globalSession){ # Server module
v <- reactiveValues(data = data)
output[[id]] <- DT::renderDataTable(v$data, selection = 'none', editable = TRUE)
proxy <- dataTableProxy(id, session = globalSession)
id_input = paste(id, "cell_edit", sep = "_")
# Could add observeEvent here to detect edit event
observeEvent(input[[id_input]], {
info = input[[id_input]]
if (!is.null(info)) {
v$data[info$row, info$col] <<- DT::coerceValue(info$value, v$data[info$row, info$col])
}
replaceData(proxy, v$data, resetPaging = FALSE)
})
return(data = reactive({v$data}))
}
ui <- fluidPage(
sidebarLayout(
sidebarPanel(
width = 2,
actionButton("btn", "Save Both")
),
mainPanel(
tabsetPanel(
tabPanel("Table1", modDtUi("editable1")),
tabPanel("Table2", modDtUi("editable2"))
)
)
)
)
server <- function(input, output, session) {
e1 <- callModule(modDt, "editable1", data = head(iris,10), id = "editable1", globalSession = session)
e2 <- callModule(modDt, "editable2", data = tail(iris,5), id = "editable2", globalSession = session)
observeEvent(input$btn, {
print("Saving...")
sheets <- list("e1" = e1(), "e2" = e2())
write_xlsx(sheets, "test.xlsx")
})
}
shinyApp(ui = ui, server = server)

shiny: updateSelectInput for a module UI (after insertUI)

The following shiny app uses modules, it works:
library(shiny)
LHSchoices <- c("X1", "X2", "X3", "X4")
LHSchoices2 <- c("S1", "S2", "S3", "S4")
#------------------------------------------------------------------------------#
# MODULE UI ----
variablesUI <- function(id, number) {
ns <- NS(id)
tagList(
fluidRow(
column(6,
selectInput(ns("variable"),
paste0("Select Variable ", number),
choices = c("Choose" = "", LHSchoices)
)
),
column(6,
numericInput(ns("value.variable"),
label = paste0("Value ", number),
value = 0, min = 0
)
)
)
)
}
#------------------------------------------------------------------------------#
# MODULE SERVER ----
variables <- function(input, output, session, variable.number){
reactive({
req(input$variable, input$value.variable)
# Create Pair: variable and its value
df <- data.frame(
"variable.number" = variable.number,
"variable" = input$variable,
"value" = input$value.variable,
stringsAsFactors = FALSE
)
return(df)
})
}
#------------------------------------------------------------------------------#
# Shiny UI ----
ui <- fixedPage(
tabsetPanel(type = "tabs",id="tabs",
tabPanel("t1",value="t1"),
tabPanel("t2",value="t2")),
variablesUI("var1", 1),
h5(""),
actionButton("insertBtn", "Add another line"),
verbatimTextOutput("test1"),
tableOutput("test2")
)
# Shiny Server ----
server <- function(input, output) {
add.variable <- reactiveValues()
add.variable$df <- data.frame("variable.number" = numeric(0),
"variable" = character(0),
"value" = numeric(0),
stringsAsFactors = FALSE)
var1 <- callModule(variables, paste0("var", 1), 1)
observe(add.variable$df[1, ] <- var1())
observeEvent(input$insertBtn, {
btn <- sum(input$insertBtn, 1)
insertUI(
selector = "h5",
where = "beforeEnd",
ui = tagList(
variablesUI(paste0("var", btn), btn)
)
)
newline <- callModule(variables, paste0("var", btn), btn)
observeEvent(newline(), {
add.variable$df[btn, ] <- newline()
})
})
output$test1 <- renderPrint({
print(add.variable$df)
})
output$test2 <- renderTable({
add.variable$df
})
}
#------------------------------------------------------------------------------#
shinyApp(ui, server)
Now, I would like to update the selectInput, with dynamic choices. For this, I found this answer, and it is possible to use the function updateSelectInput.
But in this app, the selectInput is in a module. The following doesn't work
observe({
updateSelectInput(session, "variable",
choices = choices_var()
)})
choices_var() is some reactive values (it can depend on the selected tab for example).
Here is the full code.
library(shiny)
LHSchoices <- c("X1", "X2", "X3", "X4")
LHSchoices2 <- c("S1", "S2", "S3", "S4")
#------------------------------------------------------------------------------#
# MODULE UI ----
variablesUI <- function(id, number) {
ns <- NS(id)
tagList(
fluidRow(
column(6,
selectInput(ns("variable"),
paste0("Select Variable ", number),
choices = c("Choose" = "", LHSchoices)
)
),
column(6,
numericInput(ns("value.variable"),
label = paste0("Value ", number),
value = 0, min = 0
)
)
)
)
}
#------------------------------------------------------------------------------#
# MODULE SERVER ----
variables <- function(input, output, session, variable.number){
reactive({
req(input$variable, input$value.variable)
# Create Pair: variable and its value
df <- data.frame(
"variable.number" = variable.number,
"variable" = input$variable,
"value" = input$value.variable,
stringsAsFactors = FALSE
)
return(df)
})
}
#------------------------------------------------------------------------------#
# Shiny UI ----
ui <- fixedPage(
tabsetPanel(type = "tabs",id="tabs",
tabPanel("tab1",value="t1"),
tabPanel("tab2",value="t2")),
variablesUI("var1", 1),
h5(""),
actionButton("insertBtn", "Add another line"),
verbatimTextOutput("test1"),
tableOutput("test2")
)
# Shiny Server ----
server <- function(input, output,session) {
choices_var <- reactive({
if (input$tabs=="t1"){
choices_var <- LHSchoices
}
if (input$tabs=="t2") {
choices_var <- LHSchoices2
}
return(choices_var)
})
observe({
updateSelectInput(session, "variable",
choices = choices_var()
)})
add.variable <- reactiveValues()
add.variable$df <- data.frame("variable.number" = numeric(0),
"variable" = character(0),
"value" = numeric(0),
stringsAsFactors = FALSE)
var1 <- callModule(variables, paste0("var", 1), 1)
observe(add.variable$df[1, ] <- var1())
observeEvent(input$insertBtn, {
btn <- sum(input$insertBtn, 1)
insertUI(
selector = "h5",
where = "beforeEnd",
ui = tagList(
variablesUI(paste0("var", btn), btn)
)
)
newline <- callModule(variables, paste0("var", btn), btn)
observeEvent(newline(), {
add.variable$df[btn, ] <- newline()
})
})
output$test1 <- renderPrint({
print(add.variable$df)
})
output$test2 <- renderTable({
add.variable$df
})
}
#------------------------------------------------------------------------------#
shinyApp(ui, server)
I would like to how to modify the code so that the choices can be modified.
EDIT: I succeded to update the first UI by adding the code below. So now my question is: how can we dynamically reach the variablesUI?
choices_var <<- reactive({
if (input$tabs=="t1"){
choices_var <- LHSchoices
}
if (input$tabs=="t2") {
choices_var <- LHSchoices2
}
return(choices_var)
})
observeEvent({
choices_var()
}, {
updateSelectInput(session, "var1-variable",
choices = choices_var())
})
EDIT 2: I can do it manually as below, but that would be really ugly, and the number of added UI should be limited.
observeEvent({
choices_var()
}, {
updateSelectInput(session, "var1-variable",
choices = choices_var())
})
observeEvent({
choices_var()
}, {
updateSelectInput(session, "var2-variable",
choices = choices_var())
})
EDIT 3
Now my question becomes more specific: when inserting a selectInput using insertUI, how to update the choices of newly inserted selectInput with updateSelectInput ?
Your variable input is in a module. You're trying to update it from the main server function. So you have a namespace mismatch. It also violates the principle that modules should be self-contained.
Ideally, you should update the variable input in the module which defines it. If the update depends on values which exist outside the module, you can pass them as reactives to the module server function.
*** Edit ***
Here is a simple, self-conatined example in response to OP's request for demonstration of how to update a selectInput that lives inside a module with data provided by the main server function. I've removed everything that isn't directly relevant to the purpose of the demonstration.
The app includes two instances of the module (defined by moduleUI and moduleController). Each instance has its own id, so the server can distinguish between them. The main UI also includes pair of selectInputs, each of which tells one of the module instances what to display.
The key to making this work is passing the value of the controlling seelctinput to the controller of the appropriate instance of the module, for example:
mod1 <- callModule(moduleController, "Module1", reactive({input$module1Mode}))
The module controller function looks like this
moduleController <- function(input, output, session, selector) { ... }
Note the additional argument named selector, which corresponds to the current value of the controlling selectInput. The module reacts to changes to its controller with
observeEvent(selector(), {
updateSelectInput(session, "select", choices=choiceLists[[selector()]])
})
And returns a value to the main server with
returnValue <- reactive({
input$select
})
return(returnValue)
If you play with the app, you'll see that the selection list displayed by each instance of the module can be controlled independently and the server can distinguish between (and react to) the values returned by each instance of the module.
Here's the full code:
library(shiny)
moduleUI <- function(id) {
ns <- NS(id)
wellPanel(
h4(paste0("This is module id"), id),
selectInput(ns("select"), label="Make a choice: ", choices=c())
)
}
moduleController <- function(input, output, session, selector) {
ns <- session$ns
choiceLists <- list(
"Animals"=c("Cat", "Dog", "Rabbit", "Fish"),
"Fruit"=c("Apple", "Orange", "Pear", "Rambutan"),
"Sports"=c("Football", "Cricket", "Rugby", "Volleyball"),
"Countries"=c("Great Britain", "China", "USA", "France")
)
observeEvent(selector(), {
updateSelectInput(session, "select", choices=choiceLists[[selector()]])
})
returnValue <- reactive({
input$select
})
return(returnValue)
}
ui <- fixedPage(
selectInput("module1Mode", label="Select module 1 mode", choices=c("Animals", "Fruit")),
moduleUI("Module1"),
selectInput("module2Mode", label="Select module 2 mode", choices=c("Sports", "Countries")),
moduleUI("Module2"),
textOutput("mod1Text"),
textOutput("mod2Text")
)
server <- function(input, output, session) {
mod1 <- callModule(moduleController, "Module1", reactive({input$module1Mode}))
mod2 <- callModule(moduleController, "Module2", reactive({input$module2Mode}))
observe({
if (is(mod1(), "character")) print("Ah-ha!")
})
output$mod1Text <- renderText({
paste("Module 1 selection is", mod1())
})
output$mod2Text <- renderText({
paste("Module 2 selection is", mod2())
})
}
shinyApp(ui, server)

Shiny Modules with Observes and reactiveValues

I have been trying to reconstruct the following simplistic Shiny app using modules since I believe that will be the best way to organize this code inside a much larger application where I will use these kinds of linked-slider-numeric inputs in many places.
However, I cannot figure out how to achieve the same kind of functionality from within a module.
Here's an example app that works exactly as intended, but not using modules:
library(shiny)
# Let's build a linked Slider and Numeric Input
server <- function(input, output) {
values <- reactiveValues(numval=1)
observe({
values$numval <- input$slider
})
observe({
values$numval <- input$number
})
output$slide <- renderUI({
sliderInput(
inputId = 'slider'
,label = 'SN'
,min = 0
,max = 10
,value = values$numval
)})
output$num <- renderUI({
numericInput(
inputId = 'number'
,label = 'SN'
,value = values$numval
,min = 0
,max = 10
)
})
}
ui <- fluidPage(
uiOutput('slide'),
uiOutput('num')
)
shinyApp(ui, server)
Here's my attempt. (Note that "mortalityRate" and associated strings are just an example of the variable name(s) I'll be using later). I have tried several variations on this attempt, but inevitably I get errors, usually indicating I'm doing something that can only be done inside a reactive context:
numericSliderUI <- function(id, label = "Enter value", min = 1, max = 40, value) {
ns <- NS(id)
tagList(
sliderInput(inputId = paste0(ns(id), "Slider"), label = label, min = min, max = max, value = value),
numericInput(inputId = paste0(ns(id), "Numeric"), label = label, min = min, max = max, value = value)
)
}
numericSlider <-
function(input,
output,
session,
value,
mortalityRateSlider,
mortalityRateNumeric
) {
values <- reactiveValues(mortalityRate = value())
observe({
values[['mortalityRate']] <- mortalityRateSlider()
})
observe({
values[['mortalityRate']] <- mortalityRateNumeric()
})
return( reactive( values[['mortalityRate']] ) )
}
library(shiny)
# source("modules.R") # I keep the modules in a separate file, but they're just pasted above for convenience here on StackOverflow.
ui <- fluidPage(
uiOutput('mortalityRate')
)
server <- function(input, output) {
values <- reactiveValues(mortalityRate = 1)
mortalityRateValue <- callModule(
numericSlider,
id = 'mortalityRate',
value = values[['mortalityRate']],
mortalityRateSlider = reactive( input$mortalityRateSlider ),
mortalityRateNumeric = reactive( input$mortalityRateNumeric )
)
values[['mortalityRate']] <- reactive( mortalityRateValue() )
output$mortalityRate <- renderUI(numericSliderUI('mortalityRate', value = values[['mortalityRate']]))
}
shinyApp(ui = ui, server = server)
I know that I must be doing something wrong with the reactiveValues and the way I'm using the observe statements inside the module, but this is my best attempt at using the module structure, so any help figuring out what I'm doing wrong would be very helpful.
Here is working code. There are a variety of changes, so I'll direct you to this Github page that also sets up a structure for using renderUI with modules. In general, I think the problems in your code involved trying to define reactive values inside the callModule function, and in passing the values of the sliders and numeric box back and forth.
Other features of using modules are that in your actual UI call, you need to call the UI module, where in turn you can call uiOutput. Inside renderUI is where you can set up the inputs. Additionally, inside modules you don't need the session namespaces, but you do need to wrap those ids in session$ns() to ensure they work across modules.
UI and Server Modules:
numericSliderUI <- function(id) {
ns <- NS(id)
uiOutput(ns('mortalityRate'))
}
numericSlider <- function(input, output, session) {
values <- reactiveValues(mortalityRate = 1)
observe({
values[['mortalityRate']] <- input$Slider
})
observe({
values[['mortalityRate']] <- input$Numeric
})
output$mortalityRate <- renderUI(
tagList(
sliderInput(inputId = session$ns("Slider"), label = "Enter value:", min = 1, max = 40, value = values[['mortalityRate']]),
numericInput(inputId = session$ns("Numeric"), label = "Enter value:", min = 1, max = 40, value = values[['mortalityRate']])
)
)
return(list(value = reactive({values[['mortalityRate']]})))
}
UI and Server functions:
ui <- fluidPage(
numericSliderUI('mortalityRate')
)
server <- function(input, output, session) {
mortalityRateValue <- callModule(numericSlider, 'mortalityRate')
}
shinyApp(ui = ui, server = server)

How to call a shiny module from a shiny module?

How do I call a shiny module from within a shiny module with passing selections from the first module?
As an example I wrote a app to show the Star Wars subjects from dplyr in a DT::data table (module StarWars). The related films from the same data set should be shown in another DT::data table in another sub tab (module Films).
I pass the table selected subject in a reactive value sw_rows_selected_rct from module StarWars to module Films but browser() statement in module Films is not passed.
# Test call of modules inside modules
library(tidyverse)
#' Shiny StarWars module
#'
ui_Films <-
function(id,
title = id,
...,
value = title,
icon = NULL) {
ns <- shiny::NS(id)
tab <- tabPanel(title,
h4("StarWars Films"),
DT::dataTableOutput(outputId = ns("Films")))
}
ui_StarWars <-
function(id,
title = id,
...,
value = title,
icon = NULL) {
ns <- shiny::NS(id)
tab <- tabPanel(title,
DT::dataTableOutput(outputId = ns("StarWars")),
tabsetPanel(ui_Films(
id = ns("Films"), title = "...by Films"
)))
}
ui <- shinyUI(navbarPage(
"Call Modules in Modules test",
ui_StarWars("StarWars", title = "StarWars")
))
Films <-
function(input,
output,
session,
sw_data,
sw_selection) {
ns <- session$ns
sw_films_rct <- observe({
req(sw_data, is.data.frame(sw_selection))
browser() # not reached!!!
sw_films_rct <-
sw_data %>% {
if (is_null(sw_selection))
.
else
filter(., name == sw_selection$name)
}
})
output$StarWarsFilms <- DT::renderDataTable({
req(is.data.frame(sw_films_rct))
DT::datatable(sw_films_rct,
selection = 'single',
options = list(pageLength = 5))
})
}
StarWars <-
function(input, output, session, sw_data) {
sw_rows_selected_rct = reactiveVal()
ns <- session$ns
sw_rows_selected_rct = observeEvent(input$StarWars_rows_selected, {
req(sw_data, input$StarWars_rows_selected != 0)
browser()
sw_data[input$StarWars_rows_selected, ]
})
md_films <- callModule(
module = Films,
id = "Films",
sw_data = sw_data,
sw_selection = sw_rows_selected_rct
)
output$StarWars <- DT::renderDataTable({
req(is.data.frame(sw_data))
DT::datatable(sw_data,
selection = 'single',
options = list(pageLength = 5))
})
}
server <- shinyServer(function(input, output, session) {
sw_data_rct = reactive({
dplyr::starwars %>% mutate(films = NULL,
vehicles = NULL,
starships = NULL)
})
md_StarWars = callModule(module = StarWars,
id = "StarWars",
sw_data = sw_data_rct())
})
# Run the application
shinyApp(ui = ui, server = server)
Your code had a few errors. Remember, observe and observeEvents don't have return values. Set the value of your reactives through the nameofReactive(newValue). Your initial goal is possible if you give the reactive to the module, not the current value of the reactive, so that it can change throughout the course of using the app. In the module, you then have to you the value of the reactive, by using () on the reactive. Oh, and your last output had the wrong name (output$Films should be correct). Here is the working app:
library(tidyverse)
#' Shiny StarWars module
#'
ui_Films <-
function(id, title = id, ..., value = title, icon = NULL) {
ns <- shiny::NS(id)
tab <- tabPanel(title,
h4("StarWars Films"),
DT::dataTableOutput(outputId = ns("Films"))
)
}
ui_StarWars <-
function(id, title = id, ..., value = title, icon = NULL) {
ns <- shiny::NS(id)
tab <- tabPanel(title,
DT::dataTableOutput(outputId = ns("StarWars")),
tabsetPanel(
ui_Films(id = ns("Films"), title = "...by Films"))
)
}
ui <- shinyUI(
navbarPage(
"Call Modules in Modules test",
ui_StarWars("StarWars", title = "StarWars")
)
)
Films <-
function(input, output, session, sw_data, sw_selection) {
ns <- session$ns
sw_films_rct <- reactiveVal()
observe({
sw_films_rct(sw_data() %>% {if(is_null(sw_selection())) . else filter(., name == sw_selection()$name)})
})
output$Films <- DT::renderDataTable({
req(is.data.frame(sw_films_rct()))
DT::datatable(sw_films_rct(),
selection = 'single',
options = list(pageLength = 5))
})
}
StarWars <-
function(input, output, session, sw_data) {
sw_rows_selected_rct= reactiveVal()
ns <- session$ns
observeEvent(input$StarWars_rows_selected, {
req(sw_data(), input$StarWars_rows_selected != 0)
sw_rows_selected_rct(sw_data()[input$StarWars_rows_selected,])
})
md_films <- callModule(module = Films, id = "Films",
sw_data= sw_data,
sw_selection= sw_rows_selected_rct)
output$StarWars <- DT::renderDataTable({
req(is.data.frame(sw_data()))
DT::datatable(sw_data(),
selection = 'single',
options = list(pageLength = 5))
})
}
server <- shinyServer(function(input, output, session) {
sw_data_rct= reactive({dplyr::starwars %>% mutate(films = NULL, vehicles = NULL, starships = NULL)})
md_StarWars= callModule(module = StarWars, id = "StarWars", sw_data = sw_data_rct)
})
# Run the application
shinyApp(ui = ui, server = server)

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