addLayerGroupConditional

addLayerGroupConditional

Usage

addLayerGroupConditional(map, groups = NULL, conditions = NULL)

Arguments

map

A map widget object created from leaflet.

groups

A character vector of layer group names already added to the map. These layer groups will be conditionally displayed based on the specified conditions.

conditions

A named list of conditions for displaying layer groups. Each list element should have:

• A name: a JavaScript function as string that defines the condition.

• A value: the layer group name(s) from the layers parameter to be shown when the condition evaluates to TRUE.

Example:

  conditions = list(
    "(zoomLevel) => zoomLevel < 4"                     = "group1",
    "(zoomLevel) => zoomLevel >= 4 && zoomLevel < 6"   = "group2",
    "(zoomLevel) => zoomLevel >= 6"                    = c("group3", "group4")
  )
  

See also

https://github.com/Solfisk/Leaflet.LayerGroup.Conditional for more details about the plugin.

Other LayerGroupConditional Plugin: clearConditionalLayers(), removeConditionalLayer()

Examples

library(leaflet)
library(sf)
library(leaflet.extras2)

breweries91 <- st_as_sf(breweries91)
lines <- st_as_sf(atlStorms2005)
polys <- st_as_sf(leaflet::gadmCHE)
groups <- c("atlStorms", "breweries", "gadmCHE")

leaflet() %>%
  addTiles() %>%
  # leafem::addMouseCoordinates() %>%
  addPolylines(data = lines, label = ~Name, group = groups[1]) %>%
  addCircleMarkers(data = breweries91, label = ~brewery, group = groups[2]) %>%
  addPolygons(data = polys, label = ~NAME_1, group = groups[3]) %>%
  addLayerGroupConditional(
    groups = groups,
    conditions = list(
      "(zoomLevel) => zoomLevel < 4" = groups[1],
      "(zoomLevel) => zoomLevel >= 4 & zoomLevel < 6 " = groups[2],
      "(zoomLevel) => zoomLevel >= 6" = groups[3]
    )
  ) %>%
  hideGroup(groups) %>%
  addLayersControl(
    overlayGroups = groups,
    options = layersControlOptions(collapsed = FALSE)
  )