using conditionalPanel in Shiny ui.R and server.R: different selectInput based on a condition

1
votes

I have looked at the majority of the stackoverflow posts on using conditionalPanel in shiny and still have not been able to find my bug.

I seem to be able to pass my parameters for "yr1" and "scen1" from server.R to ui.R, but the conditionalPanel does not appear to be working.

In my shiny app I have two selections to be made. Depending on the first selection, a different second set of selections should be displayed. Below is the code I am currently testing:

library(shiny)
library(httpuv)

shinyUI(pageWithSidebar(
  headerPanel("Global Temperature"),

  sidebarPanel(
    checkboxGroupInput("scen1", label = h3("Select 1 Map #1 Scenario"), 
                       choices = list("pre-2000" = "past", "post-2000: 850 ppm by 2100 (a2)"="a2","post-2000: 550 ppm by 2100 (b1)"="b1"), selected = "past"),
    conditionalPanel(condition = "input.scen1 == 'past'",
                     selectInput("yearspred1", "Select Map #1 Years Hindcasted",choices = c("1920-1939", "1940-1959", "1960-1979", "1980-1999"), selected="1920-1939", multiple=FALSE)),
    conditionalPanel(condition = "input.scen1 == 'a2'",
                     selectInput("yearspred1", "Select Map #1 Years Predicted",choices = c("2020-2039", "2040-2059","2060-2079", "2080-2099")), selected="2020-2039", multiple=FALSE),
    conditionalPanel(condition = "input.scen1 == 'b1'", 
                     selectInput("yearspred1", "Select Map #1 Years Predicted",choices = c("2020-2039", "2040-2059", "2060-2079", "2080-2099"), selected="2020-2039", multiple=FALSE)),
    ),
  mainPanel(
    h3(textOutput("add1")),
    imageOutput("plot1")
  )  

 )
)

(I do the above for two selections but just show one here)

Server.R (you would need to fill in the path for the kml options to run this):

library(shiny)
library(httpuv)
library(rWBclimate)
library(ggplot2)

# get temperature data for ensembles
st=1900
en=2100
world <- c("USA")
options(kmlpath\="/Users/n....")
world_map_df <- create_map_df(world)
world_dat <- get_ensemble_temp(world, "annualavg", start=st, end=en)
world_dat$data <- as.numeric(as.character(world_dat$data))
world_dat<-subset(world_dat,world_dat$percentile==50) #subset to median percentile
world_dat$years=paste(world_dat$fromYear,world_dat$toYear, sep="-")
world_dat<-subset(world_dat, select=-c(percentile, fromYear, toYear))

shinyServer(function(input, output){
  scenario1<-reactive({input$scen1})
  yr1<-reactive({
    switch(input$yearspred1,  
           "1920-1939" = "1920-1939",
           "1940-1959" = "1940-1959",
           "1960-1979" = "1960-1979",
           "1980-1999" = "1980-1999",
           "2020-2039" = "2020-2039",
           "2040-2059" = "2040-2059",
           "2060-2079" = "2060-2079",
           "2080-2099" = "2080-2099")
  })

  dfyr1<-reactive({subset(world_dat, world_dat$scenario==scenario1())})
  df1<-reactive({subset(dfyr1(), dfyr1()$years==yr1())})
  output$add1 <- renderText({paste("Temperature prediction for years ", yr1(), " and ", scenario1(), " scenario") })

  output$plot1<- renderPlot({
    climate_map(world_map_df,df1(),return_map = T) + scale_fill_gradient2(limits=c(-20, 34), low="blue", mid="white", high = "red", space="rgb", guide="colourbar") 
  })
})

Parameters are being passed, but the dropdown menu for "yr1" does not comply with the conditionalPanel conditions. I suspect it is in this part of the code, but I am not sure:

  yr1<-reactive({
    switch(input$yearspred1,  
           "1920-1939" = "1920-1939",
           "1940-1959" = "1940-1959",
           "1960-1979" = "1960-1979",
           "1980-1999" = "1980-1999",
           "2020-2039" = "2020-2039",
           "2040-2059" = "2040-2059",
           "2060-2079" = "2060-2079",
           "2080-2099" = "2080-2099")
  })

I tried replacing it with the following line:

yr1<-reactive({input$yearspred1})

But this did not fix the problem either.

Thanks for any help you can provide!

1
rshiny
What is the exact problem you are encountering? 'The code doesn't appear to be working' is extremely vague. – cdeterman

1 Answers

3
votes

I can see the temptation to use the same ID for each selectInput within the conditionPanel but generally you shouldn't. It is best to have clearly defined input ID's. Additionally, your switch statement is completely unnecessary like that where it just returns the exact same value that is put in. After changing the selectInput ID's it is makes much more sense to have a switch statement. You also have too many unnecessary reactive statements. Unless you plan on using those statements in other functions throughout your server.R file, there is not point to have them there and they should just be combined wherever they are to be used (i.e. the renderPlot statement). This is why the yr is made reactive because it will be used in renderText and renderPlot. The following code works appropriately.

ui.R

library(shiny)
library(httpuv)

shinyUI(pageWithSidebar(
  headerPanel("Global Temperature"),

  sidebarPanel(
    checkboxGroupInput("scen1", label = h3("Select 1 Map #1 Scenario"), 
                       choices = list("pre-2000" = "past", "post-2000: 850 ppm by 2100 (a2)"="a2","post-2000: 550 ppm by 2100 (b1)"="b1"), selected = "past"),
    conditionalPanel(condition = "input.scen1 == 'past'",
                     selectInput("yearspred1", "Select Map #1 Years Hindcasted",choices = c("1920-1939", "1940-1959", "1960-1979", "1980-1999"), selected="1920-1939", multiple=FALSE)),
    conditionalPanel(condition = "input.scen1 == 'a2'",
                     selectInput("yearspred2", "Select Map #1 Years Predicted",choices = c("2020-2039", "2040-2059","2060-2079", "2080-2099")), selected="2020-2039", multiple=FALSE),
    conditionalPanel(condition = "input.scen1 == 'b1'", 
                     selectInput("yearspred3", "Select Map #1 Years Predicted",choices = c("2020-2039", "2040-2059", "2060-2079", "2080-2099"), selected="2020-2039", multiple=FALSE))
  ),
  mainPanel(
    h3(textOutput("add1")),
    imageOutput("plot1")
  )  
  )
)

server.R

library(shiny)
library(httpuv)
library(rWBclimate)
library(ggplot2)

# get temperature data for ensembles
st=1900
en=2100
world <- c("USA")
options(kmlpath="/Users/n...")
world_map_df <- create_map_df(world)
world_dat <- get_ensemble_temp(world, "annualavg", start=st, end=en)
world_dat$data <- as.numeric(as.character(world_dat$data))
world_dat<-subset(world_dat,world_dat$percentile==50) #subset to median percentile
world_dat$years=paste(world_dat$fromYear,world_dat$toYear, sep="-")
world_dat<-subset(world_dat, select=-c(percentile, fromYear, toYear))

shinyServer(function(input, output){

  yr <- reactive({switch(
    input$scen1,
    "past" = input$yearspred1,
    "a2" = input$yearspred2,
    "b1" = input$yearspred3
  )})

  output$add1 <- renderText({paste("Temperature prediction for years ", yr(), " and ", input$scen1, " scenario") })

  output$plot1<- renderPlot({
    dfyr1<-subset(world_dat, world_dat$scenario==input$scen1)
    df1 <- subset(dfyr1, dfyr1$years==yr())
    climate_map(map_df=world_map_df,data_df=df1,return_map = T) + scale_fill_gradient2(limits=c(-20, 34), low="blue", mid="white", high = "red", space="rgb", guide="colourbar") 
  })
})