Problem in downloading data using Download Handlers in ShinyApp - r

Question

My original data of mtcar gets downloaded using Download Handlers in ShinyApp whereas i want the the modified data (using SelectInputs) to be downloaded through Handlers.
I have attached my codes as well, please let me know whats wrong with them. Many thanks:)
library(shiny)
library(tidyr)
library(dplyr)
library(readr)
library(DT)
data_table <- mtcars
# Define UI
ui <- fluidPage(
downloadButton('downLoadFilter',"Download the filtered data"),
selectInput(inputId = "cyl",
label = "cyl:",
choices = c("All",
unique(as.character(data_table$cyl))),
selected = "4",
multiple = TRUE),
selectInput(inputId = "vs",
label = "vs:",
choices = c("All",
unique(as.character(data_table$vs))),
selected = "1",
multiple = TRUE),
DT::dataTableOutput('ex1'))
server <- function(input, output) {
thedata <- reactive({
if(input$cyl != 'All'){
return(data_table[data_table$cyl == input$cyl,])
}
else if(input$vs != 'All'){
return(data_table[data_table$vs == input$vs,])
}
else{
return(data_table)
}
})
output$ex1 <- DT::renderDataTable(DT::datatable(filter = 'top',
escape = FALSE,
options = list(pageLength =
10, scrollX='500px',autoWidth = TRUE),{
thedata() # Call reactive
thedata()
}))
output$downLoadFilter <- downloadHandler(
filename = function() {
paste('Filtered data-', Sys.Date(), '.csv', sep = '')
},
content = function(path){
write_csv(thedata(),path) # Call reactive thedata()
})}
shinyApp(ui = ui, server = server)

Answer 1

You are updating thedata() only inside your renderDataTable. You need to make it a reactive and then use it for being rendered as DataTable and being downloaded.
Change your server to:
# Define server logic
server <- function(input, output) {
thedata <- reactive({
if(input$cyl != 'All'){
return(data_table[data_table$cyl == input$cyl,])
}
else{
return(data_table)
}
})
output$ex1 <- DT::renderDataTable(DT::datatable(filter = 'top',
escape = FALSE,
options = list(pageLength = 10, scrollX='500px',autoWidth = TRUE),{
thedata() # Call reactive thedata()
}))
output$downLoadFilter <- downloadHandler(
filename = function() {
paste('Filtered data-', Sys.Date(), '.csv', sep = '')
},
content = function(path){
write_csv(thedata(),path) # Call reactive thedata()
})}