add_geojson: Add Geojson

Description

The GeoJson Layer takes in GeoJson formatted data and renders it as interactive polygons, lines and points

Usage

add_geojson(
  map,
  data = get_map_data(map),
  layer_id = NULL,
  stroke_colour = NULL,
  stroke_opacity = NULL,
  stroke_width = NULL,
  dash_size = NULL,
  dash_gap = NULL,
  fill_colour = NULL,
  fill_opacity = NULL,
  radius = NULL,
  elevation = NULL,
  extruded = FALSE,
  light_settings = list(),
  legend = F,
  legend_options = NULL,
  legend_format = NULL,
  auto_highlight = FALSE,
  tooltip = NULL,
  highlight_colour = "#AAFFFFFF",
  palette = "viridis",
  na_colour = "#808080FF",
  line_width_units = c("meters", "pixels"),
  line_width_scale = 1,
  line_width_min_pixels = 0,
  elevation_scale = 1,
  point_radius_scale = 1,
  point_radius_min_pixels = 1,
  update_view = TRUE,
  focus_layer = FALSE,
  digits = 6,
  transitions = NULL,
  ...
)

Arguments

map: a mapdeck map object
data: data to be used in the layer. Can be a url to GeoJSON
layer_id: single value specifying an id for the layer. Use this value to distinguish between shape layers of the same type. Layers with the same id are likely to conflict and not plot correctly
stroke_colour: column of an sf object, or field inside a GeoJSON property to use for colour
stroke_opacity: column of an sf object, or field inside a GeoJSON property to use for opacity
stroke_width: column of an sf object, or field inside a GeoJSON property to use for width (in meters)
dash_size: size of each dash, relative to the width of the stroke
dash_gap: size of the gap between dashes, relative to the width of the stroke
fill_colour: column of an sf object, or field inside a GeoJSON property to use for colour
fill_opacity: column of an sf object, or field inside a GeoJSON property to use for opacity
radius: radius of points in meters. Default 1. See details
elevation: elevation of polygons. Default 0. See details
extruded: logical indicating if polygons should extrude from the map. If TRUE, stroke_colour for polygons is ignored
light_settings: list of light setting parameters. See light_settings
legend: either a logical indiciating if the legend(s) should be displayed, or a named list indicating which colour attributes should be included in the legend. A legend is only shown if you supply one of the colour arguments (fill or stroke)
legend_options: A list of options for controlling the legend.
legend_format: A list containing functions to apply to legend values. See section legend
auto_highlight: logical indicating if the shape under the mouse should auto-highlight
tooltip: variable of data containing text or HTML to render as a tooltip. Only works on sf objects.
highlight_colour: hex string colour to use for highlighting. Must contain the alpha component.
palette: string or matrix. String will be one of colourvalues::colour_palettes(). A matrix must have at least 5 rows, and 3 or 4 columns of values between [0, 255], where the 4th column represents the alpha. You can use a named list to specify a different palette for different colour options (where available), e.g. list(fill_colour = "viridis", stroke_colour = "inferno")
na_colour: hex string colour to use for NA values
line_width_units: The units of the line width, one of 'meters', 'pixels'. When zooming in and out, meter sizes scale with the base map, and pixel sizes remain the same on screen.
line_width_scale: The line width multiplier that multiplied to all lines, including the LineString and MultiLineString features and also the outline for Polygon and MultiPolygon features if the stroked attribute is true
line_width_min_pixels: The minimum line width in pixels.
elevation_scale: Elevation multiplier. The final elevation is calculated by elevationScale * getElevation(d). elevationScale is a handy property to scale all polygon elevation without updating the data
point_radius_scale: A global radius multiplier for all points.
point_radius_min_pixels: The minimum radius in pixels.
update_view: logical indicating if the map should update the bounds to include this layer
focus_layer: logical indicating if the map should update the bounds to only include this layer
digits: number of digits for rounding coordinates
transitions: list specifying the duration of transitions.
...: clear_legend and clear_view arguments passed to 'clear_()' functions

transitions

The transitions argument lets you specify the time it will take for the shapes to transition from one state to the next. Only works in an interactive environment (Shiny) and on WebGL-2 supported browsers and hardware.

The time is in milliseconds

Available transitions for geojson

list( fill_colour = 0, stroke_colour = 0, stroke_width = 0, elevation = 0, radius = 0 )

Raw Geojson

If using a GeoJSON string, and you do not suppply one of the colouring arguments, the function will look for these fields inside the properties field of the Geojson

fill_colour

fill_colour
fillColour
fill_color
fillColor
fill

stroke_colour

stroke_colour
strokeColour
stroke_color
strokeColor
stroke
line_colour
lineColour
line_color
lineColor
line

stroke_width

stroke_width
strokeWdith
line_width
lineWidth
width

elevation
radius

These colour values should be valid hex-colour strings.

If you do provide values for the colouring arguments, the function will assume you want to use specific fields in the geojson for colouring. However, if you only supply a fill_colour value, the function will not automatically detect the stroke_colour (and vice versa)

data

If the data is a simple feature object, the geometry column is automatically detected. If the sf object contains more than one geometry column and you want to use a specific one, you'll need to set the active geometry using sf::st_geometry( x ) <- "your_column" , where "your_column" is the name of the column you're activating. See ?sf::st_geometry

legend

The legend_options can be used to control the appearance of the legend. This should be a named list, where the names are one of

css - a string of valid css for controlling the appearance of the legend
title - a string to use for the title of the legend
digits - number to round the legend values to

If the layer allows different fill and stroke colours, you can use different options for each. See examples in add_arc.

The legend_format can be used to control the format of the values in the legend. This should be a named list, where the names are one of

fill_colour
stroke_colour

depending on which type of colouring the layer supports.

The list elements must be functions to apply to the values in the legend.

Examples

Run this code

# \donttest{

## You need a valid access token from Mapbox
key <- 'abc'
set_token( key )

## Not supplying colouring arguments, the function will try and find them in the GeoJSON
mapdeck(
 , location = c(145, -37.9)
 , zoom = 8
 , style = mapdeck_style("dark")
 , pitch = 35
) %>%
 add_geojson(
   data = geojson
   , auto_highlight = TRUE
 )

## only supplying values to use for fill, the stroke will be default
mapdeck(
 , location = c(145, -37.9)
 , zoom = 8
 , style = mapdeck_style("dark")
 , pitch = 35
) %>%
 add_geojson(
   data = geojson
   , fill_colour = "random"
 )

mapdeck(
 , location = c(145, -37.9)
 , zoom = 8
 , style = mapdeck_style("dark")
 , pitch = 35
) %>%
 add_geojson(
   data = geojson
   , fill_colour = "random"
   , stroke_colour = "random"
 )

mapdeck(
 , location = c(145, -37.9)
 , zoom = 8
 , style = mapdeck_style("dark")
 , pitch = 35
) %>%
 add_geojson(
   data = geojson
   , fill_colour = "random"
   , stroke_colour = "random"
   , elevation = 300
 )

## putting elevation and width values onto raw GeoJSON
library(geojsonsf)
sf <- geojsonsf::geojson_sf( geojson )
sf$width <- sample(1:100, size = nrow(sf), replace = TRUE)
sf$elevation <- sample(100:1000, size = nrow(sf), replace = TRUE)
geo <- geojsonsf::sf_geojson( sf )

mapdeck(
 , location = c(145, -37.9)
 , zoom = 8
 , style = mapdeck_style("dark")
 , pitch = 35
) %>%
 add_geojson(
   data = geo
   , extruded = TRUE ## required to show elevated polygons
 )

# }

Run the code above in your browser using DataLab