How to insert multiple images into shiny after click of a button? - r

Question

I created a shiny app which has two buttons as you can see in the following screenshot. I want to display 8 images which I have in this folder in the shiny app after I click the "Show Images" button. I tried using renderImages but couldn't get it to work.
Here is the code I have so far:
ui.R
fluidPage(
# Application title
titlePanel("For Fun!!"),
hr(),
sidebarLayout(
# Sidebar with a slider and selection inputs
sidebarPanel(
actionButton("update", "Print Text"),
hr(),
actionButton("test", "Show Images")
),
mainPanel(
verbatimTextOutput("plot"),
uiOutput("images")
)
)
)
server.r
server <- function(input, output) {
randomVals <- eventReactive(input$update, {
myString="Hello!"
myString
})
output$plot <- renderPrint({
myString=randomVals()
print(myString)
})
}
This is what I'm looking for as an output:
Thanks for your time

Answer 1

Try it like this.
library(shiny)
server <- shinyServer(function(input, output) {
output$files <- renderTable(input$files)
files <- reactive({
files <- input$files
files$datapath <- gsub("\\\\", "/", files$datapath)
files
})
output$images <- renderUI({
if(is.null(input$files)) return(NULL)
image_output_list <-
lapply(1:nrow(files()),
function(i)
{
imagename = paste0("image", i)
imageOutput(imagename)
})
do.call(tagList, image_output_list)
})
observe({
if(is.null(input$files)) return(NULL)
for (i in 1:nrow(files()))
{
print(i)
local({
my_i <- i
imagename = paste0("image", my_i)
print(imagename)
output[[imagename]] <-
renderImage({
list(src = files()$datapath[my_i],
alt = "Image failed to render")
}, deleteFile = FALSE)
})
}
})
})
ui <- shinyUI(fluidPage(
titlePanel("Uploading Files"),
sidebarLayout(
sidebarPanel(
fileInput(inputId = 'files',
label = 'Select an Image',
multiple = TRUE,
accept=c('image/png', 'image/jpeg'))
),
mainPanel(
tableOutput('files'),
uiOutput('images')
)
)
))
shinyApp(ui=ui,server=server)