Add a layer to a map from a source

In many cases, you will use add_layer() internal to other layer-specific functions in mapgl. Advanced users will want to use add_layer() for more fine-grained control over the appearance of their layers.

Usage

add_layer(
  map,
  id,
  type = "fill",
  source,
  source_layer = NULL,
  paint = list(),
  layout = list(),
  slot = NULL,
  min_zoom = NULL,
  max_zoom = NULL,
  popup = NULL,
  tooltip = NULL,
  hover_options = NULL,
  before_id = NULL,
  filter = NULL
)

Arguments

map

A map object created by the mapboxgl() or maplibre() functions.

id

A unique ID for the layer.

type

The type of the layer (e.g., "fill", "line", "circle").

source

The ID of the source, alternatively an sf object (which will be converted to a GeoJSON source) or a named list that specifies type and url for a remote source.

source_layer

The source layer (for vector sources).

paint

A list of paint properties for the layer.

layout

A list of layout properties for the layer.

slot

An optional slot for layer order.

min_zoom

The minimum zoom level for the layer.

max_zoom

The maximum zoom level for the layer.

popup

A column name containing information to display in a popup on click. Columns containing HTML will be parsed.

tooltip

A column name containing information to display in a tooltip on hover. Columns containing HTML will be parsed.

hover_options

A named list of options for highlighting features in the layer on hover.

before_id

The name of the layer that this layer appears "before", allowing you to insert layers below other layers in your basemap (e.g. labels).

filter

An optional filter expression to subset features in the layer.

Value

The modified map object with the new layer added.

Examples

if (FALSE) { # \dontrun{
# Load necessary libraries
library(mapgl)
library(tigris)

# Load geojson data for North Carolina tracts
nc_tracts <- tracts(state = "NC", cb = TRUE)

# Create a Mapbox GL map
map <- mapboxgl(
    style = mapbox_style("light"),
    center = c(-79.0193, 35.7596),
    zoom = 7
)

# Add a source and fill layer for North Carolina tracts
map %>%
    add_source(
        id = "nc-tracts",
        data = nc_tracts
    ) %>%
    add_layer(
        id = "nc-layer",
        type = "fill",
        source = "nc-tracts",
        paint = list(
            "fill-color" = "#888888",
            "fill-opacity" = 0.4
        )
    )
} # }