RDeck proxy

Creates an rdeck() interface for asynchronous updates of a pre-rendered rdeck map in Shiny apps.

All rdeck props can be updated through the proxy (NULL values will be discarded), layers that are added to the proxy (e.g. rdeck_proxy %>% add_h3_hexagon_layer()) will be merged with pre-rendered rdeck layers.

Layers are merged by their id. Matched layers will be updated in place, new layers will be appended and hence drawn on top of all existing layers. For layer updates, you may omit the data prop to avoid re-serialising unchanged data. All other props will assume their defaults if omitted.

Usage

rdeck_proxy(
  id,
  session = shiny::getDefaultReactiveDomain(),
  map_style = cur_value(),
  theme = cur_value(),
  initial_bounds = cur_value(),
  initial_view_state = cur_value(),
  controller = cur_value(),
  picking_radius = cur_value(),
  use_device_pixels = cur_value(),
  blending_mode = cur_value(),
  layer_selector = cur_value(),
  editor = cur_value(),
  lazy_load = deprecated(),
  ...
)

Arguments

id

<string> The map id

session

<ShinySession> The shiny session

map_style

<string> The mapbox basemap style url. See https://docs.mapbox.com/api/maps/#mapbox-styles

theme

<"kepler" | "light"> The widget theme which alters the style of the legend and tooltips.

initial_bounds

<rct/st_bbox/wk-geometry> Sets the initial bounds of the map if not NULL. Takes priority over initial_view_state. Accepts a bounding box, or a geometry from which a bounding box can be computed. Requires CRS EPSG:4326.

initial_view_state

<view_state> Defines the map position, zoom, bearing and pitch.

controller

<logical> If NULL or FALSE, the map is not interactive.

picking_radius

<number> Extra pixels around the pointer to include while picking; useful when rendering objects that are difficult to hover, e.g. thin lines, small points, etc.

use_device_pixels

<logical | number> Controls the resolution of drawing buffer used for rendering.

• TRUE: Resolution is defined by window.devicePixelRatio. On Retina/HD displays, this resolution is usually twice as big as CSS pixels resolution.

• FALSE: CSS pixels resolution is used for rendering.

• number: Custom ratio (drawing buffer resolution to CSS pixel) to determine drawing buffer size. A value less than 1 uses resolution smaller than CSS pixels, improving rendering performance at the expense of image quality; a value greater than 1 improves image quality at the expense of rendering performance.

blending_mode

<"normal" | "additive" | "subtractive"> Sets the blending mode. Blending modes:

• normal: Normal blending doesn't alter colours of overlapping objects.

• additive: Additive blending adds colours of overlapping objects. Useful for highlighting dot density on dark maps.

• subtractive: Subtractive blending darkens overlapping objects. Useful for highlighting dot density on light maps.

layer_selector

<boolean> If TRUE, the layer selector control will be enabled and layers with visibility_toggle = TRUE may be toggled. If FALSE, the layer selector control won't be rendered.

editor

<boolean|editor_options> Whether to render the polygon editor. If TRUE, renders with the default editor_options(). If FALSE, the polygon editor is not rendered.

lazy_load

. Maps are always eagerly rendered.

...

Additional parameters that will be forwarded to deck.gl javascript without validation nor processing. All dots must be named and will be camelCased when serialised. A warning is raised when dots are used, warning class rdeck_dots_nonempty.

Examples

if (FALSE) { # \dontrun{
library(shiny)
library(dplyr)
library(h3jsr)
library(viridis)

ui <- fillPage(
  rdeckOutput("map", height = "100%"),
  absolutePanel(
    top = 10, left = 10,
    sliderInput("range", "value", 0, 1, c(0, 1), step = 0.1)
  )
)

h3_data <- tibble(
  hexagon = get_res0() %>%
    get_children(res = 3) %>%
    unlist() %>%
    unique(),
  value = runif(length(hexagon))
)

map <- rdeck() %>%
  add_h3_hexagon_layer(
    id = "h3_hexagon",
    name = "hexagons",
    data = h3_data,
    get_fill_color = scale_color_quantize(
      col = value,
      palette = viridis(6, 0.3)
    ),
    pickable = TRUE,
    auto_highlight = TRUE,
    tooltip = c(hexagon, value)
  )

server <- function(input, output, session) {
  output$map <- renderRdeck(map)

  filtered_data <- reactive({
    h3_data %>%
      filter(value >= input$range[1] & value <= input$range[2])
  })

  observe({
    rdeck_proxy("map") %>%
      add_h3_hexagon_layer(
        id = "h3_hexagon",
        name = "hexagons",
        data = filtered_data(),
        get_fill_color = scale_color_quantize(
          col = value,
          palette = cividis(6, 0.3)
        ),
        pickable = TRUE,
        auto_highlight = TRUE,
        tooltip = c(hexagon, value)
      )
  })
}

app <- shinyApp(ui, server)
} # }