Merge branch 'plot' into develop

DESCRIPTION

@@ -32,7 +32,8 @@ Imports:
   sf,
   tidygraph,
   utils,
-  pillar
+  pillar,
+  graphics
 Suggests:
     tidyverse,
     knitr,

NAMESPACE

@@ -7,6 +7,7 @@ S3method(as_sfnetwork,sf)
 S3method(as_sfnetwork,tbl_graph)
 S3method(as_tbl_graph,sfnetwork)
 S3method(as_tibble,sfnetwork)
+S3method(plot,sfnetwork)
 S3method(print,sfnetwork)
 S3method(st_area,sfnetwork)
 S3method(st_as_sf,sfnetwork)
@@ -56,6 +57,7 @@ export(st_overlaps.sfnetwork)
 export(st_relate.sfnetwork)
 export(st_touches.sfnetwork)
 export(st_within.sfnetwork)
+importFrom(graphics,plot)
 importFrom(igraph,is_directed)
 importFrom(pillar,style_subtle)
 importFrom(rlang,"!!")

R/plot.R

@@ -0,0 +1,26 @@
+#' Plot sfnetwork object
+#'
+#' Plot spatially explicit graph components (nodes and edges) of an sfnetwork on a map
+#'
+#' @param x object of class sfnetwork
+#' @param ... further parameters passed to \code{\link[sf]{plot}}
+#' @importFrom graphics plot
+#' @export
+plot.sfnetwork = function(x, ...){
+  dots = list(...)
+
+  pch_missing = is.null(dots$pch)
+
+  sfn = sf::st_geometry(sf::st_as_sf(activate(x, "nodes")))
+
+  if (has_spatially_explicit_edges(x)) {
+    sfe = sf::st_geometry(sf::st_as_sf(activate(x, "edges")))
+    sfgraph = c(sfn, sfe)
+    dots$x = sfgraph
+  } else {
+    dots$x = sfn
+  }
+
+  dots$pch = if (pch_missing) 20 else dots$pch
+  do.call(plot, dots)
+}