One reactive function to be displayed on two different pages interactively - r

Question

I have an application which has 3 tabItems. I want to use a slider on second page to display same result on 3rd page interactively, i.e. if 2nd page slider changes then 3rd page slider should also change respectively.
I have a reactive function on server side
choose_segment <- reactive({
Multiple conditions for dropdown{Due to security cant share the exact code.}
})
and this choose_segment is refered in UI once and now i want to use it on the third page as well, but when i am calling the function on third page it is not displaying any thing on ui and also not giving any error.
in UI it is called inside UIoutput.
uiOutput(choose_segment())
My observations : I think as per my study we can not call one function directly twice, so what i am doing is i have made two different functions and calling same function from them, i.e.
output$chooseSegment1 <- renderUI({
choose_segment()
})
output$chooseSegment2 <- renderUI({
choose_segment()
})
Issue : it is giving me output but they both are not interactive :(
Kindly provide a solution so that i can make both the sliders work in interactive manner.

Answer 1

I have faced the same scenario, in that i was suppose to change the code structure.
I made dynamic output uiOutput to the Dropdown menu ob ui and then used the same in my server as Input$xyz in observe on server and it worked for me.
Code :
UI : column(3, selectInput(inputId="ABC",label= "Choose ABC"))
column(3, selectInput(inputId="ABC1",label= "Choose ABC"))
Server : observe({
if(is.null(tab2_summary())) return(NULL)
updateSelectInput(session, "ABC", value = input$ABC)
})
observe({
updateSelectInput(session, "ABC1", value = input$ABC)
})
observe({
updateSelectInput(session, "ABC", value = input$ABC1)
})
So this is how i was able to make the selectInput interactive on two different page.
For your reference there is one full reproducible code.
Kindly refer,
library(shiny)
# UI ----------------------------------------------------------
ui <- navbarPage("Navbar!",
tabPanel("Plot", sidebarLayout(sidebarPanel(
radioButtons("yaxis1", "y-axis", c("speed"="speed", "dist"="dist"),
selected = "speed"
)),
mainPanel( plotOutput("plot"),
textOutput("test2")))), # for input checking
tabPanel("Summary", sidebarLayout(sidebarPanel(
radioButtons("yaxis2", "grouping-var", c("speed"="speed", "dist"="dist")
)),
mainPanel(
verbatimTextOutput("summary"),
textOutput("test1")
)))
)
# Server ------------------------------------------
server <- function(input, output, session) {
observe({
x <- input$yaxis1
updateRadioButtons(session, "yaxis2", selected = x)
})
observe({
y <- input$yaxis2
updateRadioButtons(session, "yaxis1", selected = y)
})
# output$test1 <- renderPrint({cat("yaxis1", input$yaxis1)})
# output$test2 <- renderPrint({cat("yaxis2", input$yaxis2)})
# output$plot <- renderPlot({ plot(cars[['speed']], cars[[input$yaxis1]]) })
# output$summary <- renderPrint({ summary(cars[[input$yaxis2]]) })
}
shinyApp(ui, server)
I Hope it will of your help.