Getter functions now evaluate ... with tidy evaluation

NEWS.md

@@ -14,6 +14,10 @@
   this update adds the option to use labels instead of an arrow using the 
   `labels` argument.
 * `create_layout()` now returns a modified tibble rather than a data.frame
+* The `...` in `get_nodes()`, `get_edges()`, and `get_con()` now accepts 
+  tidy evaluation. `get_nodes()` and `get_con()` will get evaluated on the node
+  data in the original order (layouts may reorder nodes), and `get_edges()` will
+  get evaluated on the edge data (#272)
 
 # ggraph 2.1.0
 

R/connections.R

@@ -16,7 +16,9 @@
 #' @param paths A list of integer vectors giving the index of nodes defining
 #' connections
 #'
-#' @param ... Additional information to be added to the final data output
+#' @param ... Additional information to be added to the final data output.
+#' Accepts expressions that will be evaluated on the node data in it's
+#' original order (irrespective of any reordering by the layout)
 #'
 #' @param weight An expression to be evaluated on the edge data to provide
 #' weights for the shortest path calculations
@@ -33,6 +35,7 @@ get_con <- function(from = integer(), to = integer(), paths = NULL, ..., weight
   if (length(from) != length(to)) {
     cli::cli_abort('{.arg from} and {.arg to} must be of equal length')
   }
+  dots <- enquos(...)
   function(layout) {
     if (length(from) == 0) {
       return(NULL)
@@ -55,8 +58,10 @@ get_con <- function(from = integer(), to = integer(), paths = NULL, ..., weight
       )
       nodes <- vec_rbind(nodes, extra)
     }
-    extra_data <- lapply(list2(...), function(x) {
-      rep(x, length.out = length(from))[nodes$con.id]
+    layout <- layout[order(layout$.ggraph.orig_index), ]
+    extra_data <- lapply(dots, function(x) {
+      val <- eval_tidy(x, layout)
+      rep(val, length.out = length(from))[nodes$con.id]
     })
     if (length(extra_data) > 0) {
       nodes <- cbind(

R/edges.R

@@ -49,7 +49,7 @@
 #' details for more information
 #'
 #' @param ... Additional data that will be cbind'ed together with the returned
-#' edge data.
+#' edge data. Accepts expressions that will be evaluated on the edge data
 #'
 #' @return A data.frame with columns dependent on format as well as the graph
 #' type. In addition to the columns discussed in the details section,
@@ -74,9 +74,10 @@
 #'
 get_edges <- function(format = 'short', collapse = 'none', ...) {
   if (!collapse %in% c('none', 'all', 'direction')) {
-    cli::cli_abort('{.arg ollapse} must be either {.val none}, {.val all} or {.val direction}')
+    cli::cli_abort('{.arg collapse} must be either {.val none}, {.val all} or {.val direction}')
   }
-  function(layout) {
+  dots <- enquos(...)
+  function(layout) {browser()
     edges <- collect_edges(layout)
     edges <- switch(
       collapse,
@@ -90,7 +91,10 @@ get_edges <- function(format = 'short', collapse = 'none', ...) {
       long = format_long_edges(edges, layout),
       cli::cli_abort('Unknown {.arg format}. Use either {.val short} or {.val long}')
     )
-    extra_data <- lapply(list2(...), rep, length.out = nrow(edges))
+    extra_data <- lapply(dots, function(x) {
+      val <- eval_tidy(x, edges)
+      rep(val, length.out = nrow(edges))
+    })
     if (length(extra_data) > 0) {
       edges <- cbind(
         edges,

R/nodes.R

@@ -10,7 +10,8 @@
 #' node layers.
 #'
 #' @param ... Additional data that should be cbind'ed together with the node
-#' data.
+#' data. Accepts expressions that will be evaluated on the node data in it's
+#' original order (irrespective of any reordering by the layout)
 #'
 #' @return A data.frame with the node data as well of any additional data
 #' supplied through `...`
@@ -20,8 +21,13 @@
 #' @export
 #'
 get_nodes <- function(...) {
+  dots <- enquos(...)
   function(layout) {
-    extra_data <- lapply(list2(...), rep, length.out = nrow(layout))
+    layout_reorder <- layout[order(layout$.ggraph.orig_index), ]
+    extra_data <- lapply(dots, function(x) {
+      val <- eval_tidy(x, layout_reorder)
+      rep(val, length.out = nrow(layout))[layout$.ggraph.orig_index]
+    })
     if (length(extra_data) > 0) {
       layout <- cbind(
         layout,