Styjun

Continuing from Mark's suggestion here I am now using uiOutput and renderUI.

The code below displays an animated gif ("anione"). When the "Again" button is pressed it resets Chrome with Javascript in ways that I don't fully understand and then simulates my larger program by overwriting the original animated gif with another animated gif ("anitwo").

However, "anitwo" is not displayed, "anione" is displayed. I can view the local file and see that it was written and view it successfully by opening it in Chrome. How do I view a different file of the same name?

I realize that I am inconsistent in my use of "www/tmp/ani.gif" and "tmp/ani.gif" and understand that shiny looks for files in "www". Yet, without these inconsistencies I get file not found errors.

ani.gif and ani2.gif are here.

library(shiny)
library(shinyjs)
library(magick)

jsCode <- '
shinyjs.reset_anim = function() 
 var div_elem = document.getElementById("anim_plot");
 var img_elem = div_elem.getElementsByTagName("img")[0];
 var src_value = img_elem.getAttribute("src");
 img_elem.setAttribute("src", "");
 img_elem.setAttribute("src", src_value);

'


# Define UI ----
ui <- fluidPage(useShinyjs(),
 extendShinyjs(text = jsCode),
 uiOutput('anim_plot'),
 fluidRow(
 column(3, 
 actionButton("do_again", "Again")
 )
 )
)

# Define server logic ----
server <- function(input, output) 


 output$anim_plot <- renderUI(
 img(src = 'tmp/ani.gif',
 width = '900')
 )

 observeEvent(input$do_again, 
 print("Again")
 js$reset_anim()

 # When Again clicked, simulate the creation of a new animated gif by reading in a file and 
 # over writing the old one. Try displaying this new animated gif.

 img2 <- image_read("www/tmp/ani2.gif")
 image_write(img2, path = "www/tmp/ani.gif")

 output$anim_plot <- renderUI(
 img(src = 'tmp/ani.gif',
 width = '900')
 )
 )


shinyApp(ui = ui, server = server) 

Can't you simply do

library(shiny)

# Define UI ----
ui <- fluidPage(
 uiOutput('anim_plot'),
 fluidRow(
 column(3, 
 actionButton("do_again", "Again")
 )
 )
)

# Define server logic ----
server <- function(input, output) 

 gif <- reactiveVal("ani.gif")

 observeEvent(input$do_again, 
 gif("ani2.gif")
 )

 output$anim_plot <- renderUI(
 img(src = gif(), width = "256")
 )



shinyApp(ui = ui, server = server)