RenderPrint not updating on observeEvent - shiny

Question

When clicking on action button, I can see the google sheet downloading and date printed in console but the filetime in renderPrint is not updating?
library(httr)
set_config( config( ssl_verifypeer = 0L ) )
library(googlesheets)
suppressMessages(library(dplyr))
library(shiny)
library(shinydashboard)
library(shinyjs)
ui <- dashboardPage(
dashboardHeader(title = "Basic dashboard"),
dashboardSidebar(),
dashboardBody(
fluidRow(
#One action button to download data from google spreadsheet
actionButton("refreshbutton", label = "Refresh"),
#two textoutput to show date of downloaded file
textOutput("refreshdate")
)
)
)
)
server <- function(input, output) {
observeEvent(input$refreshbutton, {
#On click download data from google spreadsheet
pulldata <- gs_key("19bPhlp7MjDZFNJcDUmHGJDxkh2h2U5j05S0c18HfBgE") %>%
gs_read_csv(ws="vs working", col_names=TRUE)
#Write data in csv
write.csv(pulldata, file = "attrition.csv")
data <- read.csv(file="attrition.csv", header = TRUE)
#capture modified time from csv
filetime <- file.mtime("attrition.csv")
print(filetime)
#inform on completion after refresh
})
#print filetime in refreshdate1
output$refreshdate <- renderPrint({
filetime # <- This is not updating???
})
}
shinyApp(ui, server)
Along with the above code, when Google spreadsheet is downloading, I assume the site should go to grey mode indicating refresh - this also is not happening? I mean it should show somehow that new data is in process till complete?

Answer 1

The reason why it is not working is because the scope of the filetime variable is within the observeEvent. You cannot assign a variable outside its scope using observeEvent, instead use eventReactive.
Just checked it, gs_key is throwing an error for me even in R console, otherwise this is the solution you were looking for regarding reactivity.
server <- function(input, output) {
observeEvent(input$refreshbutton, {
#On click download data from google spreadsheet
pulldata <- gs_key("19bPhlp7MjDZFNJcDUmHGJDxkh2h2U5j05S0c18HfBgE") %>%
gs_read_csv(ws="vs working", col_names=TRUE)
#Write data in csv
write.csv(pulldata, file = "attrition.csv")
#read.csv(file="attrition.csv", header = TRUE)
})
filetime <- eventReactive(input$refreshbutton, {
file.mtime("attrition.csv")
})
#print filetime in refreshdate1
output$refreshdate <- renderPrint({
filetime()
})
}
Error message:
Expected content-type:
application/atom+xml; charset=UTF-8
Actual content-type:
text/html; charset=UTF-8