fixes #429, which is yet yet another WAT of RJSONIO

perhaps we really should consider switching to jsonlite...

NEWS

@@ -27,6 +27,9 @@ shiny 0.9.1.9XXX
 * `sliderInput` and `selectizeInput`/`selectInput` now use a standard horizontal
   size instead of filling up all available horizontal space.
 
+* Fixed a bug of renderDataTable() when the data object only has 1 row and 1
+  column. (Thanks, ZJ Dai, #429)
+
 shiny 0.9.1
 --------------------------------------------------------------------------------
 

R/utils.R

@@ -606,7 +606,11 @@ dataTablesJSON <- function(data, req) {
       fdata <- data[i, , drop = FALSE]  # filtered data
     } else fdata <- data
     fdata <- unname(as.matrix(fdata))
+    # WAT: toJSON(list(x = matrix(nrow = 0, ncol = 1))) => {"x": } (#299)
     if (nrow(fdata) == 0) fdata <- list()
+    # WAT: toJSON(list(x = matrix(1:2))) => {x: [ [1], [2] ]}, however,
+    # toJSON(list(x = matrix(1))) => {x: [ 1 ]} (loss of dimension, #429)
+    if (all(dim(fdata) == 1)) fdata <- list(list(fdata[1, 1]))
 
     res <- toJSON(list(
       sEcho = as.integer(sEcho),