Create a new sf layer that auto-maps geometry data

The layer_sf() function is a variant of layer() meant to be used by extension developers who are writing new sf-based geoms or stats. The sf layer checks whether the data contains a geometry column, and if one is found it is automatically mapped to the geometry aesthetic.

layer_sf(geom = NULL, stat = NULL, data = NULL, mapping = NULL,
  position = NULL, params = list(), inherit.aes = TRUE,
  check.aes = TRUE, check.param = TRUE, show.legend = NA)

Arguments

geom	The geometric object to use display the data
stat	The statistical transformation to use on the data for this layer, as a string.
data	The data to be displayed in this layer. There are three options: If NULL, the default, the data is inherited from the plot data as specified in the call to ggplot(). A data.frame, or other object, will override the plot data. All objects will be fortified to produce a data frame. See fortify() for which variables will be created. A function will be called with a single argument, the plot data. The return value must be a data.frame, and will be used as the layer data. A function can be created from a formula (e.g. ~ head(.x, 10)).
mapping	Set of aesthetic mappings created by aes() or aes_(). If specified and inherit.aes = TRUE (the default), it is combined with the default mapping at the top level of the plot. You must supply mapping if there is no plot mapping.
position	Position adjustment, either as a string, or the result of a call to a position adjustment function.
params	Additional parameters to the geom and stat.
inherit.aes	If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders().
check.aes	If TRUE, the default, will check that supplied parameters and aesthetics are understood by the geom or stat. Use FALSE to suppress the checks.
check.param	If TRUE, the default, will check that supplied parameters and aesthetics are understood by the geom or stat. Use FALSE to suppress the checks.
show.legend	logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes. It can also be a named logical vector to finely select the aesthetics to display.