selecting a marker on leaflet, from a DT row click and vice versa

Question

The minimal example below renders a leaflet map with 3 markets, and a DT table with 3 records. When a market on the map is selected, so to is the matching record on the table. However, what I cannot do, is to also have the reverse of that, where a clicked row on the table also shows the related popup on the map.

I have been unable to find an example R shiny leaflet app that does something similar.

CODE tweaked to reflect initial comments

library(shiny)
library(leaflet)
library(DT)
library(tidyverse)

# Define UI for application that draws a histogram
ui <- fluidPage(
   
    leafletOutput("opsMap"),
    DT::dataTableOutput('ranksDT')
)

# Define server logic required to draw a histogram
server <- function(input, output) {
   
    lats <- c(21.608889,21.693056, 24.04)
    longs <- c(-74.650833, -73.095,-74.341944)
    popups <- c('a','b','c')
    layerids <- c('a','b','c')
    iconNames <- c('cog','cog','cog')
    iconColors <- c('red','red','red')
    
    sampleData <- tibble(lats,longs, popups,layerids,iconNames,iconColors)

    score <- c(7,3,9)
    
    locationRanks <- tibble(popups, score)
        
    output$opsMap <- renderLeaflet({
        
        leaflet() %>%
            addTiles() %>% 
            addAwesomeMarkers(lat = sampleData$lats, 
                              lng = sampleData$longs, 
                              popup = sampleData$popups, 
                              layerId = sampleData$layerids,
                              icon = makeAwesomeIcon(icon=sampleData$iconNames, 
                                                     markerColor=sampleData$iconColors))
    })
    
    output$ranksDT <- DT::renderDataTable({
        d1 <- datatable(locationRanks,
                        selection = 'single',
                        rownames=FALSE,
                        options = list(dom = 'tpi',
                                       pageLength =5,
                                       paging=FALSE,
                                       searching=FALSE
                        )
        )
        d1
    })
    
    # create a reactive value that will store the click position
    mapClick <- reactiveValues(clickedMarker=NULL)
    mapClick <- reactiveValues(clickedGroup=NULL)
    
    # create a reactive for the DT  table
    locationClick <-reactiveValues(clickedRow = NULL)
    
    # observe click events
    observe({
        mapClick$clickedMarker <- paste(input$opsMap_marker_click$id)
        mapClick$clickedGroup <- paste(input$opsMap_marker_click$group)
        locationClick$clickedRow <- input$ranksDT_rows_selected
    })
    
    # define a proxy variable for the plant rank table
    proxy1 = dataTableProxy('ranksDT')
    # when map is clicked, make the same table row selection - need row number
    observeEvent(input$opsMap_marker_click$id, {
        a <- which(locationRanks[1] == input$opsMap_marker_click$id)
        proxy1 %>% selectRows(a)
    })
    
    
    proxy2 = leafletProxy('opsMap', session = shiny::getDefaultReactiveDomain())
    # if table is clicked, select the same market from the map
    observeEvent(locationClick$clickedRow, {
        a <- as.character(locationRanks[locationClick$clickedRow,1])
        cat(file=stderr(),"clicked row", locationClick$clickedRow, a,'\n')
        #proxy2 %>% opsMap_marker_click$id <- a
    })
    
    
}

# Run the application 
shinyApp(ui = ui, server = server)

Answer 1

A solution could be to use input$map01_marker_click$id together with dataTableProxy(), selectRows() and selectPage() if you want to highlight rows in the datatable.

In order to highlight markers, i think you could either use some javascript to simulate a click on the marker. But i would also go for the easier way to adding a highlighted marker and removing it afterwards.

Basically your question was partly answered in this question: Shiny - how to highlight an object on a leaflet map when selecting a record in a datatable? and the remaining part was in one of the answers. -> credits to them. As the code was quity lengthy, i made the effort to reduce it towards a minimal reproducible example.

Minimal reproducible example:

library(shiny)
library(leaflet)
library(DT)

qDat <- quakes[1:10, ]
qDat$id <- seq.int(nrow(qDat))

ui <- fluidPage(
  mainPanel(
    leafletOutput('map01'),
    dataTableOutput('table01')
  )
)

server <- function(input,output){
  
  output$table01 <- renderDataTable({
    DT::datatable(qDat, selection = "single", options = list(stateSave = TRUE))
  })
  
  # to keep track of previously selected row
  prev_row <- reactiveVal()
  
  # new icon style
  highlight_icon = makeAwesomeIcon(icon = 'flag', markerColor = 'green', iconColor = 'white')
  
  observeEvent(input$table01_rows_selected, {
    row_selected = qDat[input$table01_rows_selected, ]
    proxy <- leafletProxy('map01')
    proxy %>%
      addAwesomeMarkers(popup = as.character(row_selected$mag),
                        layerId = as.character(row_selected$id),
                        lng = row_selected$long, 
                        lat = row_selected$lat,
                        icon = highlight_icon)
    
    # Reset previously selected marker
    if(!is.null(prev_row())){
      proxy %>%
        addMarkers(popup = as.character(prev_row()$mag), 
                   layerId = as.character(prev_row()$id),
                   lng = prev_row()$long, 
                   lat = prev_row()$lat)
    }
    # set new value to reactiveVal 
    prev_row(row_selected)
  })
  
  output$map01 <- renderLeaflet({
    leaflet(data = qDat) %>% 
      addTiles() %>%
      addMarkers(popup = ~as.character(mag), layerId = as.character(qDat$id)) 
  })
  
  observeEvent(input$map01_marker_click, {
    clickId <- input$map01_marker_click$id
    dataTableProxy("table01") %>%
      selectRows(which(qDat$id == clickId)) %>%
      selectPage(which(input$table01_rows_all == clickId) %/% input$table01_state$length + 1)
  })
}

shinyApp(ui = ui, server = server)

Answer 2

This is not a solution, just some things that I found out about the code when looking at it.

1. The ID plantRanks only appears once in your code.

That is in input$plantRanksDT_rows_selected. Such things are easy to find and easy to fix. The correct id should be the output id of the datatable, so ranksDT. Once you replace that, you will see a second issue

2. proxy2 %>% opsMap_marker_click$id <- a makes no sense.

input$opsMap_marker_click$id exists but can obviously not be written. I don't exactly know how leaflet proxys work, but

leaflet::addMarkers()

looks promising. Good luck!