Event_data in 4.9.0 missing code to process situation if data is NULL

It seems that in the new R plotly 4.9.0 version, there is a change in the event_data code that causes errors if the plot is not yet build.
i.e. a situation where a plot_ly plot is not build because the data it needs is not yet available in the plot by means of a req(data) inside the plot_ly() block. The observeEvent(event_data("plotly_click", source = 'A_plot'), { ....}) used to work fine before, but now throws errors, and does so for all forms of event_data.

example of an error message I get now:

Warning: The 'plotly_click' event tied a source ID of 'plotlyplot.testplot' is not registered. In order to obtain this event data, please add event_register(p, 'plotly_click') to the plot (p) that you wish to obtain event data from.

The app below demonstrates the problem with version 4.9.0:

   library(shiny)
    library(plotly)



rm(list = ls(), envir = environment()) ## to prevent cross over from old runs

testData = data.frame(day = sample(seq(as.Date('1999/01/01'), as.Date('2000/01/01'), by="day"), 24), frequency = sample(1:5, 24, replace = T ), datecoloring = sample(1:2, 24, replace = T ))
testData$dayPOSIXct <- as.POSIXct(testData$day)

dateRangeMin <- min(testData$day)
dateRangeMax <- max(testData$day)

ui <- fluidPage(
  actionButton(inputId = 'Load', label = 'Data'),
  plotlyOutput('testplot', width = 700, height = 500)

)


server <- function(input, output,session) {

  values <- reactiveValues()

  observeEvent(input$Load, { 
    values$testData <- testData
    })

  output$testplot <- renderPlotly({ 
    req(values$testData)
    p <-  plot_ly(data = values$testData, source = 'testplot',
                  color  = as.factor(values$testData$datecoloring), colors = c('#339fff', '#eaf5ff'),
                  opacity= 0.5, showlegend = T,
                  marker = list(line = list(width = 2, color = '#0000ff')),
                  hoverinfo = "text",
                  text = ~paste('Files:', values$testData$frequency, '<br>Date:', format(values$testData$day, format = '%Y-%m-%d'), sep = ' '))%>%
      add_bars( x = ~dayPOSIXct, y =  ~frequency,   type = "bar", width = 36000000
      )
    p
  })

  observeEvent(event_data("plotly_relayout", source = "testplot"),{
    #any code here, doesn't matter, bug happens already
  })


}

shinyApp(ui, server)

[bklingen]

related to issue #1528

[cpsievert]

It's important to note that this is a warning, not an error. In this case, the warning is a false positive...notice that this does right thing (prints the relayout event to the R console)

observeEvent(event_data("plotly_relayout", source = "testplot"),{
    print(event_data("plotly_relayout", source = "testplot"))
  })

It's unfortunate, but I don't think I can do anything to suppress the warning in this sort of example (i.e. using observeEvent()), so I'll be closing here, but #1528 seems to be a slightly different issue that I might be able to do something about

It is still highly annoying to have false positive warnings. Also since suppressMessages() and suppressWarnings() wrappers don't seem to affect it at all. I'm trying to write my app with zero console printing and 9 pages of plotly errors doesn't look very professional. version 4.8.0 didn't have the warning and I don't see why we need it to be honest.

[cpsievert]

I understand it's annoying, but there are good technical reasons as to why event_data() now throws a warning in this case. On page load, you're calling event_data() and referencing a plot that doesn't yet exist, and there's no way for event_data() to know that the plot might exist in the future, so it throws a warning.

If you need to get rid of the warnings, you can do this

relayout_data <- reactive({
    req(values$testData)
    event_data("plotly_relayout", source = "testplot")
  })
  
  observeEvent(relayout_data(),{
    print(relayout_data())
  })

The req() here will make sure you're not calling event_data() before the relevant plotly graph is rendered.

Thanks for the help cpsievert! Don't ask me how, but this still gives me the error messages. I'm going to try and find out if I can reproduce it in a minimal example.

Ok, small update: the plot I'm trying to solve this for is normally inside a dropdownButton. Once I moved the plot out into the main page, the warning disappeared. However, if the plot is somewhere else, the reactive approach still happily generates the error, as the data needed for the plot is available (after going through the loading files procedure in my app, but the plot is not build until the dropdownbutton is opened, and between loading data and displaying the plot, the warning still happens..... sadly

I don't see how there is a way to construct a way to so to say "req("is the plot actually build yet")" approach

I would be very curious to hear the necessity for the warning message and why returning NULL until there is actual event data isn't sufficient.
I literally tried every trick in the book (that I know) to suppress messages, warnings, trycatch, !is.null, req etc etc, but while some do stop further code, the warning message is printed.

I can understand perhaps some need for a specific output in some situations, but I honestly don't see the need for merely printing a message on console that you can't get rid off no matter what. It's just a message, without any further implications on anything so I don't see how that "is needed" as you stated.

[ismirsehregal]

For future readers: This is the related SO question. In the end it's still possible to prevent the warning using req() (also with the dropdownButton - see this).

[RyanMorton-USDA]

Adding the req() creates a new dependency for that reactive object that causes other problems. If the values are dependent on another screen, the req() will pull the user to the downstream use of the event_data, like drill-down on another tab. This is not a safe solution for many of us - particularly when using priority = 'event'.

[cpsievert]

@RyanMorton-USDA a fix was recently merged related to this (#2337). Do your problems go away with the development version (remotes::install_github("plotly/plotly.R"))?

[RyanMorton-USDA]

@RyanMorton-USDA a fix was recently merged related to this (#2337). Do your problems go away with the development version (remotes::install_github("plotly/plotly.R"))?

First, thank you! We can give it a go, but it's a largish gov't app that needs stable versions. If it does work, any idea on a release date.

[asadow]

@RyanMorton-USDA
How about tracking rendering using a reactiveVal?

## Reactive for tracking if the plot has been rendered
plot_rendered <- reactiveVal()

output$testplot <- renderPlotly({ 
    req(values$testData)
    plot_rendered(FALSE)
    p <-  plot_ly()
    session$onFlushed(\() plot_rendered(TRUE), once = FALSE)
    p
)}

then

relayout_data <- reactive({
    req(plot_rendered())
    event_data("plotly_relayout", source = "testplot")
  })