R Shiny - Can't Display Prerendered Image

Question

I have a prerendered image in the images folder of the Shiny app folder. I'm trying to get the app to render the image EXG.jpeg, but only the alt text shows up. What's going wrong?

\Server File

setwd('C:/Users/E0265074/Documents/PrelimShiny/')

  function(input, output) {output$Option1 = renderUI({

  if (input$study == 'EX') {

    selectInput('differ', label='Patient ID', choices = c('013412-826-001-002','013412-840-001-001','013412-840-001-002','013412-840-001-003','013412-840-001-004'))

  }

})

output$plot <- renderImage({
      return(list(
        src = "./images/EXG.jpeg",
        contentType = "image/jpeg",
        alt = "Face"
      ))
    })

})

\UI File

library(shiny) 


shinyUI(fluidPage(

  titlePanel('Biomarker Comparison'),

  sidebarLayout(sidebarPanel(

    tabsetPanel(type = c('tabs'), 

                tabPanel('Plot 1 Options', selectInput('study', label = 'Study Type', choices = c('EX')), 
                         uiOutput('Option1'), 
                         uiOutput('Option2'), 
                         uiOutput('Option3')

                ),

                tabPanel('Plot 2 Options', selectInput('studya', label = 'Study Type', choices = c('EX')), 
                         uiOutput('Option1a'), 
                         uiOutput('Option2a'), 
                         uiOutput('Option3a')
                )

    ), 

  ),


  mainPanel(imageOutput('img1')
  )




  )

))

Answer 1

You weren't using the correct imageOutput label. img1 is wrong, you needed plot because that is how the output list entry is named. So this works:

library(shiny)

u <- shinyUI(fluidPage(
  titlePanel('Biomarker Comparison'),
  sidebarLayout(sidebarPanel(
    tabsetPanel(type = c('tabs'), 
                
                tabPanel('Plot 1 Options', selectInput('study', label = 'Study Type', 
                                                                  choices = c('EX')), 
                         uiOutput('Option1'), 
                         uiOutput('Option2'), 
                         uiOutput('Option3')
                ),
                tabPanel('Plot 2 Options', selectInput('studya', label = 'Study Type', 
                                                                choices = c('EX')), 
                         uiOutput('Option1a'), 
                         uiOutput('Option2a'), 
                         uiOutput('Option3a')
                )
    )
  ),
    mainPanel(imageOutput('plot')
  )
  )
))
s <- function(input, output) {
  
  output$Option1 = renderUI({
    if (input$study == 'EX') {
      
      selectInput('differ', label='Patient ID', 
                  choices = c('013412-826-001-002','013412-840-001-001',
                              '013412-840-001-002',
                              '013412-840-001-003','013412-840-001-004'))
    }
  })
  output$plot <- renderImage({
    return(list(
      src = "./images/EXG.jpeg",
      contentType = "image/jpeg",
      alt = "Face"
    ))
  }, deleteFile = FALSE)
}
shinyApp(ui = u, server = s) 

Yielding:

Update:

I added a deleteFile=FALSE at the end to keep renderImage from deleting it every time it ran. Not sure why it wants to do this by default.