`selectedpoints` does not function properly when a vector is passed using `plotlyProxy` & `"restyle"`.

Bug/Unexpected Behavior

When updating a scatter plot's selectedpoints in a Shiny server using "restyle" on a plotlyProxy, single value vectors don't update the graph. E.g., passing c(1) to selectedpoints won't update the graph.

However, if we duplicate this value, e.g., c(1, 1) and pass it to selectedpoints, the 1 point will be selected.

Reproducible example:

# selected points single value incorrect behavior
library(shiny)

ui <- fluidPage(fluidRow(plotly::plotlyOutput("graph"),
                         DT::DTOutput("table")))

server <- function(input, output, session) {
  output$table <- DT::renderDT({
    cars
  })
  
  output$graph <- plotly::renderPlotly({
    plotly::plot_ly(
      cars,
      x = ~ speed,
      y = ~ dist,
      selected = list(marker = list(color = "red")),
      type = "scatter",
      mode = "markers",
      source = "graph"
    ) %>%
      plotly::layout(dragmode = "select",
                     clickmode = "event+select") %>%
      plotly::event_register("plotly_selected")
  })
  
  plot_proxy <- plotly::plotlyProxy("graph")
  table_proxy <- DT::dataTableProxy("table")
  
  selected <-
    reactive({
      plotly::event_data("plotly_selected", source = "graph")
    })
  
  observeEvent(selected(), {
    selected <- selected()$pointNumber + 1
    table_proxy %>% DT::selectRows(selected)
  })
  
  observeEvent(input$table_cell_clicked, {
    selected_rows <- input$table_rows_selected - 1

   #### comment this conditional to see the bug ####
    if (length(selected_rows) == 1) {
      selected_rows <- rep(selected_rows, 2)
    }
   #### end comment this conditional to see the bug ####

   plotly::plotlyProxyInvoke(
      plotly::plotlyProxy("graph", session),
      "restyle",
      list(selectedpoints = list(selected_rows)),
      0
    )
  })
  
}

shinyApp(ui, server)

Inizia eseguendo l’esempio riproducibile R Shiny fornito e confronta plotlyProxyInvoke con selected_rows contenente c(1) rispetto a c(1, 1). Traccia l’aggiornamento di selectedpoints attraverso la chiamata "restyle" di plotlyProxy; il lavoro è completato quando un vettore con un singolo valore seleziona il punto senza duplicarlo.