Merge pull request #1544 from ostephens/display-null

Added display of `null` in data table view

main/webapp/modules/core/scripts/views/data-table/cell-ui.js

@@ -60,7 +60,7 @@ DataTableCellUI.prototype._render = function() {
   .mouseleave(function() { editLink.css("visibility", "hidden"); });
 
   if (!cell || ("v" in cell && cell.v === null)) {
-    $('<span>').html("&nbsp;").appendTo(divContent);
+    $('<span>').addClass("data-table-null").html('null').appendTo(divContent);
   } else if ("e" in cell) {
     $('<span>').addClass("data-table-error").text(cell.e).appendTo(divContent);
   } else if (!("r" in cell) || !cell.r) {

main/webapp/modules/core/styles/views/data-table-view.less

@@ -201,6 +201,10 @@ div.data-table-cell-content-numeric > a.data-table-cell-edit {
   color: #282;
   }
 
+.data-table-null {
+  color: #aaa;
+  }
+
 .data-table-error {
   color: red;
   }