Shiny Image Download Examples. 'remote_image_download.R' does not need local images. 'local_image_download.R' requires local files. To run the app, runApp('remote_image_download.R').

local_image_download.R

# This method assumes that the files 'casaos.png' and 'shiny-test.txt' exist in the 'www' subdirectory. 
# They don't have to be in the 'www' subdirectory. If they're located elsewhere, modify the file paths accordingly.

library(shiny)

# UI
ui <- fluidPage(
  titlePanel("Image Download Example"),
  
  mainPanel(
    h3("Download Image File"),
    
    div(
      "Click here to download the image: ",
      downloadButton("downloadImage", 
                    label = "casaos.png", 
                    class = "btn-link",
                    style = "padding: 0; border: none; background: none; color: #337ab7; text-decoration: underline;")
    ),
    
    br(),
    
    div(
      "Click here to download the text file: ",
      downloadButton("downloadText", 
                    label = "shiny-test.txt", 
                    class = "btn-link",
                    style = "padding: 0; border: none; background: none; color: #337ab7; text-decoration: underline;")
    ),
    
    br(), br(),
    
    h4("Image Preview:"),
    imageOutput("imagePreview")
  )
)

# Server
server <- function(input, output, session) {
  
  # Display image preview
  output$imagePreview <- renderImage({
    list(
      src = normalizePath("www/casaos.png"),
      contentType = "image/png",
      width = 300,
      alt = "CasaOS Image"
    )
  }, deleteFile = FALSE)
  
  # Download handler for image
  output$downloadImage <- downloadHandler(
    filename = "casaos.png",
    content = function(file) {
      file.copy("www/casaos.png", file)
    },
    contentType = "image/png"
  )
  
  # Download handler for text file
  output$downloadText <- downloadHandler(
    filename = "shiny-test.txt",
    content = function(file) {
      file.copy("www/shiny-test.txt", file)
    },
    contentType = "text/plain"
  )
}

# Run the app
shinyApp(ui = ui, server = server)

remote_image_download.R

library(shiny)

# UI
ui <- fluidPage(
  titlePanel("Remote Image Download Example"),
  
  mainPanel(
    h3("Download Remote Image File"),
    
    # Method 1: Download remote image
    div(
      "Click here to download the remote image: ",
      downloadButton("downloadRemoteImage", 
                    label = "casaos.png", 
                    class = "btn-link",
                    style = "padding: 0; border: none; background: none; color: #337ab7; text-decoration: underline;")
    ),
    
    br(), br(),
    
    h4("Image Preview:"),
    
    # Method 1: Display remote image directly in UI (simplest)
    h5("Method 1 - Direct HTML img tag:"),
    tags$img(src = "https://raw.githubusercontent.com/bman2408/casaos-icons/refs/heads/main/images/casaos.png", 
             width = "300px", alt = "CasaOS Remote Image"),
    
    br(), br(),
    
    # Method 2: Display remote image via renderUI (better for remote images)
    h5("Method 2 - Using renderUI:"),
    uiOutput("remoteImagePreview")
  )
)

# Server
server <- function(input, output, session) {
  
  # Remote image URL
  remote_url <- "https://raw.githubusercontent.com/bman2408/casaos-icons/refs/heads/main/images/casaos.png"
  
  # Method 2: Display remote image using renderUI (works better for remote URLs)
  output$remoteImagePreview <- renderUI({
    tags$img(src = remote_url, 
             width = "300px", 
             alt = "CasaOS Remote Image",
             style = "border: 1px solid #ccc;")
  })
  
  # Download handler for remote image
  output$downloadRemoteImage <- downloadHandler(
    filename = "casaos.png",
    content = function(file) {
      # Download the remote file
      download.file(remote_url, file, mode = "wb")
    },
    contentType = "image/png"
  )
}

# Run the app
shinyApp(ui = ui, server = server)