download bottom after filter dataset - r

Question

I am trying to download my file after filtering my data. when i run the below code the result is the only empty file is downloaded (not the filtered data).
Please note that this is multiple shiny app not a single one.
the first part is the UI and second part is the server.
please see the code below:
library(shiny)
#library(DT)
library(dplyr)
library(ggplot2)
#UI
fluidPage(
titlePanel("IN_PATIENT"),
# Create a new Row in the UI for selectInputs
fluidRow(
column(2,selectInput("HOSPITAL_NAME",
"Hospital Name:",
c("All",
unique(as.character(IN_PATIENT$HOSPITAL_NAME))))
),
column(2,selectInput("FINAL_GENDER",
"Gender:",
c("All",
unique(as.character(IN_PATIENT$FINAL_GENDER))))
),
column(2,selectInput("FINAL_NATIONALITY_STATUS",
"Nationality Status:",
c("All",
unique(as.character(IN_PATIENT$FINAL_NATIONALITY_STATUS))))
)
),
# Button
downloadButton("downloadData", "Download"),
DT::dataTableOutput("table")
)
#Server
function(input, output,session) {
# Filter data based on selections
output$table <- DT::renderDataTable(DT::datatable({
df <- IN_PATIENT
if (input$HOSPITAL_NAME != "All") {
df <- df[df$HOSPITAL_NAME == input$HOSPITAL_NAME,]
}
if (input$FINAL_GENDER != "All") {
df <- df[df$FINAL_GENDER == input$FINAL_GENDER,]
}
if (input$FINAL_NATIONALITY_STATUS != "All") {
df <- df[df$FINAL_NATIONALITY_STATUS == input$FINAL_NATIONALITY_STATUS,]
}
df
}))
output$downloadData <- downloadHandler(
filename = function() {
paste("df-",Sys.Date(), ".csv", sep = "")
},
content = function(file) {
write.csv(df, file, row.names = FALSE)
}
)
}

Answer 1

Since you don't provide sample data, I made test data with mtcars. The best solution in Shiny is to make your data as a reactive object that is passed to renderDT and downloadHandler:
library(shiny)
library(DT)
library(dplyr)
library(ggplot2)
IN_PATIENT <- mtcars %>% tibble::rownames_to_column() %>% rename(HOSPITAL_NAME = rowname,
FINAL_GENDER = vs,
FINAL_NATIONALITY_STATUS = carb)
ui <- fluidPage(
titlePanel("IN_PATIENT"),
# Create a new Row in the UI for selectInputs
fluidRow(
column(2,selectInput("HOSPITAL_NAME",
"Hospital Name:",
c("All",
unique(as.character(IN_PATIENT$HOSPITAL_NAME))))
),
column(2,selectInput("FINAL_GENDER",
"Gender:",
c("All",
unique(as.character(IN_PATIENT$FINAL_GENDER))))
),
column(2,selectInput("FINAL_NATIONALITY_STATUS",
"Nationality Status:",
c("All",
unique(as.character(IN_PATIENT$FINAL_NATIONALITY_STATUS))))
)
),
# Button
downloadButton("downloadData", "Download"),
DT::DTOutput("table")
)
#Server
server <- function(input, output,session) {
df <- reactive({
df <- IN_PATIENT
if (input$HOSPITAL_NAME != "All") {
df <- df[df$HOSPITAL_NAME == input$HOSPITAL_NAME,]
}
if (input$FINAL_GENDER != "All") {
df <- df[df$FINAL_GENDER == input$FINAL_GENDER,]
}
if (input$FINAL_NATIONALITY_STATUS != "All") {
df <- df[df$FINAL_NATIONALITY_STATUS == input$FINAL_NATIONALITY_STATUS,]
}
df
})
# Filter data based on selections
output$table <- DT::renderDT(datatable(df()))
output$downloadData <- downloadHandler(
filename = function() {
paste("df-",Sys.Date(), ".csv", sep = "")
},
content = function(file) {
write.csv(df(), file, row.names = FALSE)
})
}
shinyApp(ui, server)