Is there a way to save screenshots of a R Shiny app to the root directory with {capture} package instead of downloading?

Question

I have a shiny app that generates a wordcloud using the package wordcloud2. I am using the capture package to take a screenshot of the wordcloud. I have also tried other similar packages such as shinyscreenshot and snapper. They all provide a way to take screenshots of a portion of the app or the whole app and download the screenshot. But in my use case, I need to save the image to the root directory of the app when I click the button instead of downloading it. Is there a way to do so?

Here is a reproducible example:

library(shiny)
library(shinydashboard)
library(wordcloud2)
library(capture)

ui <- dashboardPage(
  title = "wordcloud",
  header = dashboardHeader(
    title = "Wordcloud"
  ),
  sidebar = dashboardSidebar(),
  body = dashboardBody(
    fluidRow(
      column(width = 3),
      column(
        width = 6,
        box(
          title = "wordcloud", solidHeader = TRUE, status = "primary", width = 12,
          wordcloud2Output("wordcloud")
        ),
        id = "cloud"
      ),
      column(width = 3)
    ),
    fluidRow(
      div(
        capture(
          selector = "#cloud",
          filename = "cloud",
          icon("camera"), "Downlaod wordcloud",
          format = "png"
        ),
        style = "text-align: center;"
      )
    )
  )
)

server <- function(input, output){
  output$wordcloud <- renderWordcloud2(
    wordcloud2(demoFreq, size=1, color='random-dark')
  )
}

shinyApp(ui, server)

Thanks in advance.

Answer 1

The latest release of shinyscreenshoot (0.1.0) indeed only lets you download the png file. There is a new option for saving the file to a server directory. Let's install the new version:

devtools::install_github("daattali/shinyscreenshot@a4d374d")

Clicking on the button at this app will trigger the creation of a file screenshoot.png in the current working directory in the R session at the server's disk:

library(shiny)
library(shinydashboard)
library(wordcloud2)
library(shinyscreenshot)

ui <- dashboardPage(
  title = "wordcloud",
  header = dashboardHeader(
    title = "Wordcloud"
  ),
  sidebar = dashboardSidebar(),
  body = dashboardBody(
    fluidRow(
      column(width = 3),
      column(
        width = 6,
        box(
          title = "wordcloud", solidHeader = TRUE,
          status = "primary", width = 12,
          wordcloud2Output("wordcloud")
        ),
        id = "cloud"
      ),
      column(width = 3)
    ),
    fluidRow(
      actionButton("save_screenshoot", "Save screenshoot")
    )
  )
)

server <- function(input, output){
  output$wordcloud <- renderWordcloud2(
    wordcloud2(demoFreq, size=1, color='random-dark')
  )
  
  observeEvent(input$save_screenshoot, {
    screenshot(
      selector = "#wordcloud",
      download = FALSE,
      server_dir = ".",
      filename = "screenshoot",
    )
  }
  )
}

shinyApp(ui, server)