clicking same plotly marker twice does not trigger events twice - r

Question

I am using Plotly's event_data("plotly_click") to do stuff (opening a modal) after the user clicked on a marker in a scatter plot. Afterwards (e.g. closing the modal), event_data("plotly_click") does of course not change and clicking on the same marker therefore does not trigger the same action again.
Minimal example:
library(plotly)
ui <- fluidPage(
plotlyOutput("plot")
)
server <- function(input, output, session) {
output$plot <- renderPlotly({
mtcars %>% plot_ly(x=~disp, y=~cyl)
})
# Do stuff after clicking on a marker in the plot
observeEvent(event_data("plotly_click"), {
print("do some stuff now") # this is not executed after second click on same marker
})
}
shinyApp(ui, server)
I have tried workarounds with shinyjs's onclick, to no avail (it works well in empty areas of the plot but not when clicking on markers):
shinyjs::onclick(id="plot", print("clicked"))
I have also tried using a reactive Value that stores the last click and is reset immediately afterwards (e.g. by event_data("plotly_hover")), but all tries fail because event_data("plotly_click") remains in its old value.
Can anyone help?

Answer 1

[Edit: The issue has been fixed in Plotly 4.9.0. See answer below. This answer works up to Plotly 4.8.0. From plotly 4.9.0., delete the string .clientValue- from the source code or use below answer.]
I finally solved this issue. I know this is bothering some people, so I'll post my solution here:
Basically I use shinyjs package to reset the data about the last click (the source where event_data("plotly_click") gets its information from) on a certain event (a button in my case).
The definition of the function is (note that "A" needs to be replaced with plotly-source string if used):
extendShinyjs(text = "shinyjs.resetClick = function() { Shiny.onInputChange('.clientValue-plotly_click-A', 'null'); }")
Then this is called upon button click by js$resetClick().
Minimal example:
library(shiny)
library(plotly)
library(shinyjs)
ui <- shinyUI(
fluidPage(
useShinyjs(),
# code to reset plotlys event_data("plotly_click", source="A") to NULL -> executed upon action button click
# note that "A" needs to be replaced with plotly source string if used
extendShinyjs(text = "shinyjs.resetClick = function() { Shiny.onInputChange('.clientValue-plotly_click-A', 'null'); }"),
actionButton("reset", "Reset plotly click value"),
plotlyOutput("plot"),
verbatimTextOutput("clickevent")
)
)
server <- shinyServer(function(input, output) {
output$plot <- renderPlotly({
plot_ly(mtcars, x=~cyl, y=~mpg)
})
output$clickevent <- renderPrint({
event_data("plotly_click")
})
observeEvent(input$reset, {
js$resetClick()
})
})
shinyApp(ui, server)

Answer 2

The issue has finally been fixed on Plotly side: https://github.com/ropensci/plotly/issues/1043
event_data("plotly_click", priority = "event") updates on every click, not only on shiny input change (as before). Working from Plotly 4.9.0 on.
Minimal example using Plotly 4.9.0:
library(shiny)
library(plotly)
ui <- shinyUI(
fluidPage(
plotlyOutput("plot", height = 200),
verbatimTextOutput("time_last_click")
)
)
server <- shinyServer(function(input, output) {
output$plot <- renderPlotly({
plot_ly(mtcars[1,], x=~cyl, y=~mpg, size = 1)
})
output$time_last_click <- renderPrint({
tmp <- event_data("plotly_click", priority = "event")
Sys.time()
})
})
shinyApp(ui, server)

Answer 3

I had the same problem, and came up with a solution where I specified the source argument of the plotly object to be a reactive value as follows:
In plot_ly(data,x,y,...,source = x) and event_data(...,source = x) let x be an element of a reactiveValues object. When your event triggers, change the value of x (increment or hash), which instantiates a new event_data() object.
Worked like a charm.