Expose option to disable dataframe nesting

R/fromJSON.R

@@ -23,6 +23,7 @@
 #' @param simplifyVector coerce JSON arrays containing only primitives into an atomic vector
 #' @param simplifyDataFrame coerce JSON arrays containing only records (JSON objects) into a data frame
 #' @param simplifyMatrix coerce JSON arrays containing vectors of equal mode and dimension into matrix or array
+#' @param nesting allow data frames to contain other data frame as columns
 #' @param flatten automatically \code{\link{flatten}} nested data frames into a single non-nested data frame
 #' @param x the object to be encoded
 #' @param dataframe how to encode data.frame objects: must be one of 'rows', 'columns' or 'values'
@@ -75,7 +76,7 @@
 #' identical(data3, flatten(data2))
 #' }
 fromJSON <- function(txt, simplifyVector = TRUE, simplifyDataFrame = simplifyVector,
-  simplifyMatrix = simplifyVector, flatten = FALSE, ...) {
+  simplifyMatrix = simplifyVector, flatten = FALSE, nesting = TRUE, ...) {
 
   # check type
   if (!is.character(txt) && !inherits(txt, "connection")) {
@@ -98,7 +99,7 @@ fromJSON <- function(txt, simplifyVector = TRUE, simplifyDataFrame = simplifyVec
 
   # call the actual function (with deprecated arguments)
   parse_and_simplify(txt = txt, simplifyVector = simplifyVector, simplifyDataFrame = simplifyDataFrame,
-    simplifyMatrix = simplifyMatrix, flatten = flatten, ...)
+    simplifyMatrix = simplifyMatrix, nesting = nesting, flatten = flatten, ...)
 }
 
 parse_and_simplify <- function(txt, simplifyVector = TRUE, simplifyDataFrame = simplifyVector,

R/simplify.R

@@ -1,15 +1,15 @@
 simplify <- function(x, simplifyVector = TRUE, simplifyDataFrame = TRUE, simplifyMatrix = TRUE,
   simplifyDate = simplifyVector, homoList = TRUE, flatten = FALSE, columnmajor = FALSE,
-  simplifySubMatrix = simplifyMatrix) {
+  simplifySubMatrix = simplifyMatrix, nesting = TRUE, allowNestHere = TRUE) {
 
   #This includes '[]' and '{}')
   if (!is.list(x) || !length(x)) {
     return(x)
   }
 
   # list can be a dataframe recordlist
-  if (isTRUE(simplifyDataFrame) && is.recordlist(x)) {
-    mydf <- simplifyDataFrame(x, flatten = flatten, simplifyMatrix = simplifySubMatrix)
+  if (isTRUE(allowNestHere) && isTRUE(simplifyDataFrame) && is.recordlist(x)) {
+    mydf <- simplifyDataFrame(x, flatten = flatten, simplifyMatrix = simplifySubMatrix, nesting = nesting)
     if(isTRUE(simplifyDate) && is.data.frame(mydf) && is.datelist(mydf)){
       return(parse_date(mydf[["$date"]]))
     }
@@ -23,7 +23,7 @@ simplify <- function(x, simplifyVector = TRUE, simplifyDataFrame = TRUE, simplif
 
   # apply recursively
   out <- lapply(x, simplify, simplifyVector = simplifyVector, simplifyDataFrame = simplifyDataFrame,
-    simplifyMatrix = simplifySubMatrix, columnmajor = columnmajor, flatten = flatten)
+    simplifyMatrix = simplifySubMatrix, columnmajor = columnmajor, flatten = flatten, nesting = nesting)
 
   # fix for mongo style dates turning into scalars *after* simplifying
   # only happens when simplifyDataframe=FALSE

R/simplifyDataFrame.R

@@ -1,4 +1,4 @@
-simplifyDataFrame <- function(recordlist, columns, flatten, simplifyMatrix) {
+simplifyDataFrame <- function(recordlist, columns, flatten, simplifyMatrix, nesting) {
 
   # no records at all
   if (!length(recordlist)) {
@@ -26,8 +26,8 @@ simplifyDataFrame <- function(recordlist, columns, flatten, simplifyMatrix) {
   columnlist <- transpose_list(recordlist, columns)
 
   # simplify vectors and nested data frames
-  columnlist <- lapply(columnlist, simplify, simplifyVector = TRUE, simplifyDataFrame = TRUE,
-    simplifyMatrix = FALSE, simplifySubMatrix = simplifyMatrix, flatten = flatten)
+  columnlist <- lapply(columnlist, simplify, simplifyMatrix = FALSE, simplifySubMatrix = simplifyMatrix,
+                       flatten = flatten, nesting = nesting, allowNestHere = nesting)
 
   # check that all elements have equal length
   columnlengths <- unlist(vapply(columnlist, function(z) {