Merge pull request #355 from jcheng5/bugfix/null-children

Ignore NULL tag elements

R/tags.R

@@ -126,7 +126,7 @@ tag <- function(`_tag_name`, varArgs) {
   # Unnamed arguments are flattened and added as children.
   # Use unname() to remove the names attribute from the list, which would
   # consist of empty strings anyway.
-  children <- flattenTags(unname(varArgs[!named_idx]))
+  children <- dropNullsOrEmpty(flattenTags(unname(varArgs[!named_idx])))
 
   # Return tag data structure
   structure(

R/utils.R

@@ -60,6 +60,14 @@ dropNulls <- function(x) {
   x[!vapply(x, is.null, FUN.VALUE=logical(1))]
 }
 
+nullOrEmpty <- function(x) {
+  is.null(x) || length(x) == 0
+}
+# Given a vector or list, drop all the NULL items in it
+dropNullsOrEmpty <- function(x) {
+  x[!vapply(x, nullOrEmpty, FUN.VALUE=logical(1))]
+}
+
 knownContentTypes <- Map$new()
 knownContentTypes$mset(
   html='text/html; charset=UTF-8',