support for downloadButton()

[kyle-power]

Workaround for PrimaryButton() as a download button

[jakubsob]

Hello @kyle-power! A download button is not supported by shiny.fluent. See the following workaround on how you can overcome this and use any button to trigger shiny::downloadHandler:

library(shiny)
library(shiny.fluent)
library(shinyjs)

ui <- fluentPage(
  useShinyjs(),
  PrimaryButton.shinyInput(
    "downloadButton",
    text = "Download",
    iconProps = list(iconName = "Download")
  ),
  div(
    style = "visibility: hidden;",
    downloadButton("download", label = "")
  )
)

server <- function(input, output, session) {
  observeEvent(input$downloadButton, {
    click("download")
  })
  
  output$download <- downloadHandler(
    filename = function() {
      paste("data-", Sys.Date(), ".csv", sep="")
    },
    content = function(file) {
      write.csv(iris, file)
    }
  )
}

shinyApp(ui, server)

[kamilzyla]

Thanks @kyle-power for your question, and @jakubsob for a workaround! Starting downloads from React is a feature that we could add to shiny.react in a future release - I created issue Appsilon/shiny.react#11 to track it.

[jhk0530]

Hi, all.
I tried to solve my download button problem using workaround given by @jakubsob .

But in my code, download button will open new page instead of download file.

so I deleted almost every code to find what's problem, and found this.

When download button is exist in Stack it won't work properly (instead it will open new page)

So In my case, I replaced Stack to div and it worked.

Below is minimal reproducible example.

I'm even not sure what's different between div and Stack but, you may want to note.

Thanks.

---

library(shiny)
library(shiny.fluent)
#> 
#> Attaching package: 'shiny.fluent'
#> The following object is masked from 'package:shiny':
#> 
#>     runExample
library(shinyjs)
#> 
#> Attaching package: 'shinyjs'
#> The following object is masked from 'package:shiny.fluent':
#> 
#>     runExample
#> The following object is masked from 'package:shiny':
#> 
#>     runExample
#> The following objects are masked from 'package:methods':
#> 
#>     removeClass, show

ui <- fluentPage(
  useShinyjs(),
  PrimaryButton.shinyInput(
    "downloadButton",
    text = "Download",
    iconProps = list(iconName = "Download")
  ),
  Stack(
    style = "visibility: hidden;",
    downloadButton("download", label = "")
  )
)

server <- function(input, output, session) {
  observeEvent(input$downloadButton, {
    click("download")
  })
  
  output$download <- downloadHandler(
    filename = function() {
      paste("data-", Sys.Date(), ".csv", sep="")
    },
    content = function(file) {
      write.csv(iris, file)
    }
  )
}

shinyApp(ui, server)
#> 
#> Listening on http://127.0.0.1:3765

^{Created on 2023-09-12 with reprex v2.0.2}