eventreactive only happening on first click of actionbutton

[jupev]

Hi everybody,

I'm making a shiny app to interact with a database, but I ran into problems if I use an action button more than once. The first time everything works as planned, the data gets submitted, the form cleared and the table showing the content updates. The second time I want to add something, the data does get submitted but the form doesn't clear and the table does not update. From the 3rd click on the form clears again but the table still doesn't update like it is supposed to.
What am I overlooking, does anyone here have a tip for me ?

I tried to create a reproducible example:

library(shiny)
library(shinyjs)

data(iris)
mydf <- c("Sepal.Length","123")

ui <- shinyUI(
  fluidPage(
    useShinyjs(),
    h3("Factor value"),
    uiOutput("factor_select"),
    div(
      id = "factor_value_form",
      textInput(inputId="factor_value", 
                label = p("Enter the factors value:"), 
                value = ""),
      actionButton(class="submit", "submit_factor_value_button", 
                   label = "Submit data to the database"),
      h3("Data currently  in table:"),
      # show factors in database, reactive
      tableOutput('factor_value_table')
    )
  )
    
)


server <- shinyServer(function(input, output) {
  # get list of factors in database, reactive on update
  factor_list <- eventReactive(input$submit_factor_button, ignoreNULL = FALSE, {
    colnames(iris)
  })
  
  # generate reactive dropdownlist
  output$factor_select <- renderUI({
    selectInput("factor_id", label=p("Select the factor to specify: "), factor_list() )
  })
  
  # create insert if submit button is clicked
  observeEvent(input$submit_factor_value_button, {
    insert <- c(input$factor_id, input$factor_value)
    mydf <<- rbind(mydf,insert)
    # empty form
    shinyjs::reset("factor_value_form")
    # tell user submission was successful
    shinyjs::alert("The data was submitted")
    # when using button second time, alert does appear, data gets submitted, 
    # but form does not reset and table doesn't update! 3rd time works again
  })
  
  # reactive query, refresh the table on submit button, but also show data 
  # before button is pressed by using ignoreNULL = FALSE
  factor_value_info <- eventReactive(input$submit_factor_value_button, ignoreNULL = FALSE, {
    mydf
  })
  # print table with database info queried above
  output$factor_value_table <- renderTable({
    factor_value_info()
  })
})

shinyApp(ui, server)

Thanks for your time and kind regards,
Julie

[nirgrahamuk]

I havent even really looked at your code, but I pasted it into an R session, and it ran fine, without the issues you related. i.e. for every button press after typing in a value, the value input cleared, a pop up informed me of a submission, and the table recorded the value that had been typed. consistently with each attempt.

Have you tried Ctrl-Shift-F10 to restart your R session, and clearout any junk you may have. Have you tried looking at your browsers web console, to see if any javascript errors pop up ?

[jupev]

Thank you for your reply!
I actually hadn't tried opening the app in a web browser , I'm happy to find out the issues are not happening in my browser either
But even after restarting my R session, the rstudio popup-window still gives me the same issues. Am I missing a javascript-plugin or something for rstudio if that's a thing?

[nirgrahamuk]

I'm afraid I don't know, when I work with Shiny I always want it to appear in the browser.
Perhaps someone else here will chime in !