Use reactive variables in regular functions R shiny - r

Question

I'm trying to build a bilingual dashboard. In this dashboard I want to choose the right language column (either ENG or NL) based on input$language. This column serves as the levels input for a function in which a plotly graph is made.
The problem is now that when I use the radiobutton and change the language, nothing changes in the plotly graph. I'm guessing the regular function is not updating when something changes in the 'custom_levels_lang' reactive variable.
How can I make this work?
server.R
library(shinydashboard)
library(dplyr)
library(tidyr)
library(shiny)
library(plotly)
#make bilangual df
ID = c("level_1_graph1","level_1_graph1")
NL = c("Ja","Nee")
ENG = c("Yes","No")
levels_lang = data.frame(ID,NL,ENG)
#create df for pie-chart
S <- c("Ja","Nee")
n <- c(645,544)
percentage <- c(54,46)
df <- data.frame(S,n,percentage)
function(input, output, session) {
# Creating levels by language
custom_levels_lang <- reactive({
#select chosen language for input$language, then transpose all levels per
#graph number to separate columns
#gives custom_levels_lang$'name'
df <- levels_lang %>%
select(ID,one_of(input$language)) %>%
mutate(row = row_number()) %>%
spread_("ID",input$language)
#make list
df <- as.list(df)
#remove na's from list
df <- lapply(df, function(x) x[!is.na(x)])
return(df)
})
#create pie-chart
plot_pie <- function(custom_levels){
plt <- renderPlotly({
#give right levels based on chosen language
levels(df$S) <- custom_levels
#construct plot
df %>%
plot_ly(
labels = df$S,
values = ~percentage,
type = 'pie',
hole = 0.5,
textinfo = 'percent',
text = ~paste("n = ", n),
hoverinfo = 'text') %>%
layout(
showlegend = TRUE,
legend = list(x = 0.2, y = -0.3),
title = "title") %>%
config(
displaylogo = FALSE,
collaborate = FALSE,
modeBarButtonsToRemove = list('zoom2d','pan2d','zoomIn2d','zoomOut2d',
'autoScale2d','resetScale2d','toggleHover',
'toggleSpikelines','hoverClosestCartesian','hoverCompareCartesian'))
})
return(plt)
}
output$plt1 <- plot_pie(custom_levels = custom_levels_lang()$level_1_graph1)
}
ui.R
library(shinydashboard)
library(dplyr)
library(tidyr)
library(shiny)
library(plotly)
header <- dashboardHeader(
title = "Welcome",
titleWidth = 450)
sidebar <- dashboardSidebar(width = 300, radioButtons("language", label = "Kies taal", choices = list("Nederlands" = "NL", "English" ="ENG"), selected = "NL"))
body <- dashboardBody( plotlyOutput('plt1') )
dashboardPage(header,sidebar,body)

Answer 1

The renderPlotly function has to be outside the function call so that it gets notified whenever its dependency (custom_levels_lang()$level_1_graph1) changes.
In your code it's not in a reactive context, so it only gets rendered once.
plot_pie <- function(custom_levels){
#give right levels based on chosen language
levels(df$S) <- custom_levels
#construct plot
plt <- df %>%
plot_ly(
labels = df$S,
values = ~percentage,
type = 'pie',
hole = 0.5,
textinfo = 'percent',
text = ~paste("n = ", n),
hoverinfo = 'text') %>%
layout(
showlegend = TRUE,
legend = list(x = 0.2, y = -0.3),
title = "title") %>%
config(
displaylogo = FALSE,
collaborate = FALSE,
modeBarButtonsToRemove = list('zoom2d','pan2d','zoomIn2d','zoomOut2d',
'autoScale2d','resetScale2d','toggleHover',
'toggleSpikelines','hoverClosestCartesian','hoverCompareCartesian'))
return(plt)
}
output$plt1 <- renderPlotly(plot_pie(custom_levels = custom_levels_lang()$level_1_graph1))