How to access reactive value in parent module? - r

Question

What I want to achieve is to get access to the reactive value passed to a parent module from a child module. The reproducible example below shows the idea. When i click the button in mod_server_btn then its value should be printed out in the console (from within parent module):
library(shiny)
mod_ui_btn <- function(id, label = "ui1UI") {
ns <- NS(id)
shinyUI(fluidPage(
actionButton(ns("confirm"), "Submit", class='btn-primary')
))
}
mod_server_btn <- function(input, output, session) {
cond <- reactive({ input$confirm})
return(cond)
}
ui =fluidPage(
mod_ui_btn("test"),
uiOutput("example")
)
server=shinyServer(function(input, output, session) {
value <- callModule(mod_server_btn,"test")
print(value)
#print(value$cond) # these 3 don't work either
#print(value()$cond)
#print(value())
})
shinyApp(ui=ui,server=server)
However, it doesn't work. When I click the button then I got a text: reactive({input$confirm}) in the console and it's not what I want, I need to access button value. General question is - is it possible at all to get access to reactive value in a parent module?
EDIT: #rbasa, #YBS thanks for your answers. In fact in my real app I need to return more than one reactive value to parent module. Below is slightly changed code - I added second button in mod_ui_btn - now I need to return values from both buttons to the server module. I made a list of reactives but can't get access to them using observe or output$example <-:
library(shiny)
mod_ui_btn <- function(id, label = "ui1UI") {
ns <- NS(id)
shinyUI(fluidPage(
actionButton(ns("confirm"), "Submit", class='btn-primary'),
actionButton(ns("confirm2"), "Submit2", class='btn-primary')
))
}
mod_server_btn <- function(input, output, session) {
return(
list(
cond = reactive({ input$confirm}),
cond2 = reactive({ input$confirm2})
)
)
}
ui =fluidPage(
mod_ui_btn("test"),
verbatimTextOutput("example"),
verbatimTextOutput("example2")
)
server=shinyServer(function(input, output, session) {
value <- callModule(mod_server_btn,"test")
output$example <- renderPrint(value$cond)
output$example2 <- renderPrint(value$cond2)
observe({
print(value$cond) #this is how I usually catch reactives - by their name
print(value$cond2)
})
})
shinyApp(ui=ui,server=server)
I usually use return(list(..some reactive values)) to return more than one ractive value to other module and catch then using their names in parent module. Here it doesn't work even if I use observe. No value is returned.

Answer 1

You can access with value(). I would recommend to change your mod_server_btn to the one shown below, and notice the call in server. EDIT: updated for multiple variables. Try this
library(shiny)
mod_ui_btn <- function(id, label = "ui1UI") {
ns <- NS(id)
shinyUI(fluidPage(
actionButton(ns("confirm"), "Submit", class='btn-primary'),
actionButton(ns("confirm2"), "Submit2", class='btn-primary')
))
}
mod_server_btn <- function(id) {
moduleServer(id, function(input, output, session) {
return(
list(
cond = reactive(input$confirm),
cond2 = reactive(input$confirm2)
)
)
})
}
ui =fluidPage(
mod_ui_btn("test"),
verbatimTextOutput("example"),
verbatimTextOutput("example2")
)
server=shinyServer(function(input, output, session) {
# value <- callModule(mod_server_btn,"test")
value <- mod_server_btn("test")
output$example <- renderPrint(value$cond())
output$example2 <- renderPrint(value$cond2())
observe({
print(value$cond()) #this is how I usually catch reactives - by their name
print(value$cond2())
})
})
shinyApp(ui=ui,server=server)