Bugfix: Correctly sort re-ordered columns

R/datatables.R

@@ -257,6 +257,10 @@ datatable = function(
   if (is.null(options[['autoWidth']])) options$autoWidth = FALSE
   # disable CSS classes for ordered columns
   if (is.null(options[['orderClasses']])) options$orderClasses = FALSE
+  # enable column names for column reordering by default
+  if (is.null(options[['columns']])) {
+    options$columns = lapply(names(data), function(e) list(name = e))
+  }
 
   cn = base::colnames(data)
   if (missing(colnames)) {

R/shiny.R

@@ -663,6 +663,9 @@ dataTablesFilter = function(data, params) {
   for (ord in q$order) {
     k = ord[['column']]  # which column to sort
     d = ord[['dir']]     # direction asc/desc
+    # If colReorder is enabled, need to find column name rather than index
+    l = q$columns[[k]][['name']]
+    if (l %in% names(data)) k = as.character(match(l, names(data)) - 1)
     if (q$columns[[k]][['orderable']] != 'true') next
     col = data[, as.integer(k) + 1]
     oList[[length(oList) + 1]] = (if (d == 'asc') identity else `-`)(

tests/testit/test-sort.R

@@ -0,0 +1,78 @@
+library(testit)
+
+# Factors and strings are searched differently.
+# Older versions of R don't have this set.
+op = options(stringsAsFactors = FALSE)
+
+# Helpers to create client queries that run without errors
+clientQuery = function(data, columns = lapply(names(data), columnQuery)) {
+  columns = rep_len(columns, ncol(data))
+  names(columns) = seq_len(ncol(data)) - 1
+  list(
+    draw = '0',
+    start = '0',
+    length = '10',
+    escape = 'true',
+    search = list(
+      value = '',
+      regex = 'false',
+      caseInsensitive = 'true',
+      smart = 'true'
+    ),
+    columns = columns,
+    order = list()
+  )
+}
+
+columnQuery = function(name = '', orderable = TRUE) {
+  list(
+    name = name,
+    orderable = tolower(orderable),
+    searchable = 'true',
+    search = list(value = '', regex = 'false')
+  )
+}
+
+orderQuery = function(column, dir = 'asc') {
+  list(
+    column = column,
+    dir = dir
+  )
+}
+
+assert('server-side sort handler works', {
+  tbl = data.frame(
+    foo = c('foo', 'bar', 'baz'),
+    bar = c('bar', 'baz', 'foo')
+  )
+
+  query = clientQuery(tbl)
+  out = dataTablesFilter(tbl, query)
+  (identical(out$data, unname(tbl)))
+
+  query = clientQuery(tbl)
+  query$order[[1]] = orderQuery('0', 'asc')
+  tbl_sort = tbl[order(tbl$foo), ]
+  out = dataTablesFilter(tbl, query)
+  (identical(out$data, unname(tbl_sort)))
+
+  query = clientQuery(tbl)
+  query$order[[1]] = orderQuery('1', 'desc')
+  tbl_sort = tbl[order(tbl$bar, decreasing = TRUE), ]
+  out = dataTablesFilter(tbl, query)
+  (identical(out$data, unname(tbl_sort)))
+})
+
+assert('server-side sort handler works with re-ordered columns', {
+  tbl = data.frame(
+    foo = c('foo', 'bar', 'baz'),
+    bar = c('bar', 'baz', 'foo')
+  )
+
+  query = clientQuery(tbl, lapply(c("bar", "foo"), columnQuery))
+  # order is indexed against re-ordered columns
+  query$order[[1]] = orderQuery('0', 'asc')
+  tbl_sort = tbl[order(tbl$bar), ]
+  out = dataTablesFilter(tbl, query)
+  (identical(out$data, unname(tbl_sort)))
+})