event_data() triggering unexpected warning about registering

[bklingen]

Using event_data("plotly_hover", source="mysource") seems to trigger the following warning with the newest plotly version:
Warning: The 'plotly_hover' event tied a source ID of 'mysource' is not registered. In order to obtain this event data, please add event_register(p, 'plotly_hover') to the plot (p) that you wish to obtain event data from.

library(shiny)
library(plotly)

ui <- fluidPage(
        plotlyOutput("myplot"),
        verbatimTextOutput("hovered")
      )

server <- function(input, output, session) {
    
    output$myplot <- renderPlotly({
        p <- plot_ly(faithful, x=~eruptions, y=~waiting, source="mysource")
        return(p)
    })
    
    output$hovered <- renderPrint({
      event_data("plotly_hover", source="mysource")
    })

}

shinyApp(ui = ui, server = server)

[bklingen]

The relevant entry from the plotly source code:

# It's possible for event_data() to execute before any 
  # relevant input values have been registered (i.e, before 
  # relevant plotly graphs have been executed). Therefore, 
  # we delay checking that a relevant input value has been 
  # registered until shiny flushes
  session$onFlushed(
    function() {
      eventIDRegistered <- eventID %in% session$userData$plotlyShinyEventIDs
      if (!eventIDRegistered) {
        warning(
          "The '", event, "' event tied a source ID of '", source, "' ",
          "is not registered. In order to obtain this event data, ", 
          "please add `event_register(p, '", event, "')` to the plot (`p`) ",
          "that you wish to obtain event data from.",
          call. = FALSE
        )
      }
    }
  )```

[cpsievert]

Huh, the warning seems to go away if you avoid return()

library(shiny)
library(plotly)

ui <- fluidPage(
  plotlyOutput("myplot"),
  verbatimTextOutput("hovered")
)

server <- function(input, output, session) {
  
  output$myplot <- renderPlotly({
    plot_ly(faithful, x=~eruptions, y=~waiting, source="mysource")
  })
  
  output$hovered <- renderPrint({
    event_data("plotly_hover", source="mysource")
  })
  
}

shinyApp(ui = ui, server = server)

[baj12]

How would you handle returning NULL?
I need to stop plot when there is no data (or other criteria are not matched). Currently, I return(NULL),
but I guess this is not optimal. I would rather see a message saying that data needs be loaded, but I still haven't figured out how to do this...
And yes, I have the impression that without the return I see fewer warnings, but I still see some, most probably due to the return(NULL)...
Thanks a lot.
B

[dchen71]

Are there any docs on how to use event_register? I recently upgrade to the newest plotly r version and am getting event_register errors on all of my scatter plots. I have two different sources for two different plots.

Edit: I figured it out but it would be helpful if there were additional documentation and examples outside of the webinar for this update.

[cpsievert]

How would you handle returning NULL?

Avoid calling event_data() until the relevant output is non-NULL, like this #1538 (comment)

If someone can some with an example where this is sufficiently hard, I might be willing to add an official way to suppress the warning in event_data()

Are there any docs on how to use event_register?

Sort of, see ?event_register. It's worth noting though that you shouldn't need to use event_register() unless you need an event that isn't registered by default...here's a hack to get at the default events:

p <- plotly_build(plot_ly())
p$x$shinyEvents

 [1] "plotly_hover"          
 [2] "plotly_click"          
 [3] "plotly_selected"       
 [4] "plotly_relayout"       
 [5] "plotly_brushed"        
 [6] "plotly_brushing"       
 [7] "plotly_clickannotation"
 [8] "plotly_doubleclick"    
 [9] "plotly_deselect"       
[10] "plotly_afterplot" 

[CDorich]

I am still running into this issue of Warning: The 'plotly_hover' event tied a source ID of 'mysource' is not registered. In order to obtain this event data, please add event_register(p, 'plotly_hover') to the plot (p) that you wish to obtain event data from.
I've copied Carson's code from this post, and mixed it with my own editable plotly in a test shiny app and can get it to work. When I run it in a larger app I am getting the same warning but the observe() or event_data("plotly_relayout") does not seem to be working with this app. I can get the shape to move but no underlying data is changing. I am completely stuck about how to get an event_register() to work and why I am not seeing any observe occur with the edited plot.... any guidance on how to code in an event_register() or why I can't see any interaction on this plot?

[samssann]

You could give the warning a class so that these specific warnings could be turned off.

  session$onFlushed(
    function() {
      eventIDRegistered <- eventID %in% session$userData$plotlyShinyEventIDs
      if (!eventIDRegistered) {
        rlang::warn(
          paste0("The '", event, "' event tied a source ID of '", source, "' ",
          "is not registered. In order to obtain this event data, ", 
          "please add `event_register(p, '", event, "')` to the plot (`p`) ",
          "that you wish to obtain event data from."),
          class = "plotly_unregistered_event_warning"
        )
      }
    }
  )

These warnings can be disabled in the shiny server code by wrapping this around the desired code

suppressWarnings(..., classes = "plotly_unregistered_event_warning")

[sanjmeh]

I started getting this warning as soon as I started using source argument in plot_ly(). Seems there is no clear cut solution to this as I see above. Is there any?

[davidseres]

You could give the warning a class so that these specific warnings could be turned off.

  session$onFlushed(
    function() {
      eventIDRegistered <- eventID %in% session$userData$plotlyShinyEventIDs
      if (!eventIDRegistered) {
        rlang::warn(
          paste0("The '", event, "' event tied a source ID of '", source, "' ",
          "is not registered. In order to obtain this event data, ", 
          "please add `event_register(p, '", event, "')` to the plot (`p`) ",
          "that you wish to obtain event data from."),
          class = "plotly_unregistered_event_warning"
        )
      }
    }
  )

These warnings can be disabled in the shiny server code by wrapping this around the desired code

suppressWarnings(..., classes = "plotly_unregistered_event_warning")

Where does eventID come from?

[dvg-p4]

How would you handle returning NULL?

Avoid calling event_data() until the relevant output is non-NULL, like this #1538 (comment)

If someone can some with an example where this is sufficiently hard, I might be willing to add an official way to suppress the warning in event_data()

Are there any docs on how to use event_register?

Sort of, see ?event_register. It's worth noting though that you shouldn't need to use event_register() unless you need an event that isn't registered by default...here's a hack to get at the default events:

@cpsievert I'm a bit confused, if the recommended way to avoid this warning is a req() above the call, why is the warning message itself talking about event_register()?

[dvg-p4]

Also, the req() method isn't working consistently for me in a larger app. IIUC when the renderPlotly() and the reactive holding event_data() are both depending on the same reactive, there's no guarantee as to which will be executed first when that reactive becomes available--so if the shiny reactive queue happens to execute the event_data first, we see the warning.