Enabling download all with server = TRUE datatable by using invisible download button - r

Question

The goal is to enable download all data from datatable even when server = TRUE. I'm very close already thanks to this post on Github.
This works:
library(shiny)
library(DT)
callback <- JS(
"var a = document.createElement('a');",
"$(a).addClass('dt-button');",
"a.href = document.getElementById('download1').href;",
"a.download = '';",
"$(a).attr('target', '_blank');",
"$(a).text('Download');",
"$('div.dwnld').append(a);",
"$('#download1').hide();"
)
ui <- basicPage(
downloadButton("download1", ""), # no label: this button will be hidden
numericInput("nrows", "Number of rows", 10),
DTOutput("dtable")
)
server <- function(input, output, session){
output$dtable <- renderDT(
datatable(iris[1:input$nrows,],
callback = callback,
extensions = 'Buttons',
options = list(
dom = 'B<"dwnld">frtip',
buttons = list(
"copy"
)
)
)
)
output$download1 <- downloadHandler(
filename = function() {
paste("data-", Sys.Date(), ".csv", sep="")
},
content = function(file) {
write.csv(iris, file)
}
)
}
shinyApp(ui, server)
The problem is that the download button is briefly visible on app load. How do I ensure the download button is always invisible?
I tried using shinyjs::hidden(), but it causes the download to fail:
library(shiny)
library(shinyjs)
library(DT)
callback <- JS(
"var a = document.createElement('a');",
"$(a).addClass('dt-button');",
"a.href = document.getElementById('download1').href;",
"a.download = '';",
"$(a).attr('target', '_blank');",
"$(a).text('Download');",
"$('div.dwnld').append(a);",
"$('#download1').hide();"
)
ui <- basicPage(
useShinyjs(),
hidden(downloadButton("download1", "")), # no label: this button will be hidden
numericInput("nrows", "Number of rows", 10),
DTOutput("dtable")
)
server <- function(input, output, session){
output$dtable <- renderDT(
datatable(iris[1:input$nrows,],
callback = callback,
extensions = 'Buttons',
options = list(
dom = 'B<"dwnld">frtip',
buttons = list(
"copy"
)
)
)
)
output$download1 <- downloadHandler(
filename = function() {
paste("data-", Sys.Date(), ".csv", sep="")
},
content = function(file) {
write.csv(iris, file)
}
)
}
shinyApp(ui, server)
EDIT
Using div(style = 'display: none;', ...) also results in a failed download.
library(shiny)
library(DT)
callback <- JS(
"var a = document.createElement('a');",
"$(a).addClass('dt-button');",
"a.href = document.getElementById('download1').href;",
"a.download = '';",
"$(a).attr('target', '_blank');",
"$(a).text('Download');",
"$('div.dwnld').append(a);",
"$('#download1').hide();"
)
ui <- basicPage(
div(style = "display: none;", downloadButton("download1", "")), # no label: this button will be hidden
numericInput("nrows", "Number of rows", 10),
DTOutput("dtable")
)
server <- function(input, output, session){
output$dtable <- renderDT(
datatable(iris[1:input$nrows,],
callback = callback,
extensions = 'Buttons',
options = list(
dom = 'B<"dwnld">frtip',
buttons = list(
"copy"
)
)
)
)
output$download1 <- downloadHandler(
filename = function() {
paste("data-", Sys.Date(), ".csv", sep="")
},
content = function(file) {
write.csv(iris, file)
}
)
}
shinyApp(ui, server)

Answer 1

You can use the hidden style in the downloadButton as shown below.
library(shiny)
library(shinyjs)
library(DT)
callback <- JS(
"var a = document.createElement('a');",
"$(a).addClass('dt-button');",
"a.href = document.getElementById('download1').href;",
"a.download = '';",
"$(a).attr('target', '_blank');",
"$(a).text('Download');",
"$('div.dwnld').append(a);",
"$('#download1').hide();"
)
ui <- basicPage(
# useShinyjs(),
# hidden(downloadButton("download1", "")), # no label: this button will be hidden
downloadButton("download1", "", style = "visibility: hidden;"),
numericInput("nrows", "Number of rows", 10),
DTOutput("dtable")
)
server <- function(input, output, session){
output$dtable <- renderDT(
datatable(iris[1:input$nrows,],
callback = callback,
extensions = 'Buttons',
options = list(
dom = 'B<"dwnld">frtip',
buttons = list(
"copy"
)
)
)
)
output$download1 <- downloadHandler(
filename = function() {
paste("data-", Sys.Date(), ".csv", sep="")
},
content = function(file) {
write.csv(iris, file)
}
)
}
shinyApp(ui, server)

Answer 2

Include the button in an invisible div :
ui <- basicPage(
div(
style = "display: none;",
downloadButton("download1", ""), # no label: this button will be hidden
),
numericInput("nrows", "Number of rows", 10),
DTOutput("dtable")
)