Dynamically render choropleth map with sliderInput in R shiny 2

[AlexaQuinoa]

I am trying to use the slider function to select and only display selected polygons using Shiny on a Leaflet map.

The code below gets the slider to react, but I want the colour scale to represent the depth, and the slider to select and display the energy polygons (removing non-relevant polygons) but with the depth colour scale. The polygon files contain both the depth and energy data.

The following question points me in the right direction. But I cannot get this to work with my data.

Dynamically render choropleth map with sliderInput in R shiny

Shapefile wave-shp (wave.shp) on the following page: Downloads - ABPmer UK Renewables Atlas.

Here is my code:

library(shiny)
library(leaflet)
library(rgdal)
library(sf)
library(dplyr)
library(RColorBrewer)

wave_data <- read_sf("~/path/Wave.shp")

wave_data <- st_transform(wave_data, crs = '+proj=longlat 
+datum=WGS84')

## Load map

wave_data_map <- leaflet() %>% 
   addProviderTiles(providers$Esri.WorldTopoMap) %>% 
   setView(lng = -4.2026458, lat = 56.4906712, zoom = 5)
wave_data_map

bins <- c(0, 25, 50, 100, 150, 200, 300, 400, 500, 1000, 3100)
pal <- colorBin("RdYlBu", domain = wave_data$Ave_Depth, bins = 
bins)

## Add polygons

wave_data_map <- leaflet() %>% 
   addProviderTiles(providers$Esri.WorldTopoMap) %>% 
   setView(lng = -4.2026458, lat = 56.4906712, zoom = 5) %>% 
   addPolygons(data = wave_data, 
           weight = 1,
           smoothFactor = 0.5,
           color = "white", 
           fillOpacity = 0.5, 
           fillColor = pal(wave_data$Ave_Depth), 
           
)
wave_data_map

## Add legend

wave_data_map <- leaflet() %>% 
   addProviderTiles(providers$Esri.WorldTopoMap) %>% 
   setView(lng = -4.2026458, lat = 56.4906712, zoom = 5) %>% 
   addPolygons(data = wave_data, 
           weight = 1,
           smoothFactor = 0.5,
           color = "white", 
           fillOpacity = 0.3, 
           fillColor = pal(wave_data$Ave_Depth)) %>% 
   addLegend(pal = pal, 
         values = wave_data$Ave_Depth, 
         title = "Average depth",
         labFormat = labelFormat (suffix = "m"),
         opacity = 0.7, 
         position = "bottomright")
wave_data_map


# Define UI for application

ui <- bootstrapPage(
   tags$style(type = "text/css", "html, body 
                {width:100%;height:100%}"),
   leafletOutput("wave_data_map", width = "100%", height = 
                  "100%"),
   sliderInput("wave_data_slider", "Wave energy", 
                         min = 0, max = 75, 
                         value = c(min(wave_data$An_mn_P_OD), 
                         max(wave_data$An_mn_P_OD)), 
                         step = 5, 
                         round = 0.5,
                         dragRange = TRUE)
))


# Define server logic

server <- function(input, output, session) {
 wave_energy_output <- reactive ({
    wave_data %>% 
    filter(An_mn_P_OD >= input$wave_data_range[1]) %>% 
    filter(An_mn_P_OD <= input$wave_data_range[2]) 
 })
output$wave_data_map <- renderLeaflet(
  leaflet() %>% 
     addProviderTiles(providers$Esri.WorldTopoMap) %>% 
     setView(lng = -4.2026458, lat = 56.4906712, zoom = 5) %>% 
     addPolygons(data = wave_data, 
                 weight = 1,
                 smoothFactor = 0.5,
                 color = "white", 
                 fillOpacity = 0.3, 
                 fillColor = pal(wave_data$Ave_Depth)) %>% 
     addLegend(pal = pal, 
               values = wave_data$Ave_Depth, 
               title = "Average depth",
               labFormat = labelFormat (suffix = "m"),
               opacity = 0.7, 
               position = "bottomright")
)

observeEvent({input$wave_data_slider}, {
  leafletProxy("wave_data_map", data = wave_data) %>% 
     clearShapes() %>% 
     addPolygons(data = wave_energy_output,
        fillColor = pal, 
        weight = 0.0, 
        opacity = 1, 
        color = "white", 
        dashArray = 3, 
        fillOpacity = 0.7, 
     ) %>% clearControls() %>% 
     addLegend(pal = pal, 
               values = wave_data$Ave_Depth, 
               title = "Average depth",
               labFormat = labelFormat (suffix = "m"),
               opacity = 0.7, 
               position = "bottomright")
  
}
)}

# Run the application 

shinyApp(ui = ui, server = server)

Is the problem in observeEvent? When this runs I get all polygons in black, the slider does react to something, but does not return the required polygons.

Any help would really be appreciated.