[spark] Add absolute positioning to table header extender

This correctly positions the cloned header in the result tables when scrolling (absolute instead of fixed).

apps/spark/src/spark/templates/editor_components.mako

@@ -869,7 +869,8 @@ from django.utils.translation import ugettext as _
         $(el).jHueTableExtender({
           fixedHeader: true,
           includeNavigator: false,
-          parentId: snippet.id()
+          parentId: 'snippet_' + snippet.id(),
+          clonedContainerPosition: "absolute"
         });
       },
       "aoColumnDefs": [
@@ -895,7 +896,8 @@ from django.utils.translation import ugettext as _
     $(el).jHueTableExtender({
       fixedHeader: true,
       includeNavigator: false,
-      parentId: snippet.id()
+      parentId: 'snippet_' + snippet.id(),
+      clonedContainerPosition: "absolute"
     });
     $(".dataTables_filter").hide();
     var dataTableEl = $(el).parents(".dataTables_wrapper");
@@ -1187,7 +1189,8 @@ from django.utils.translation import ugettext as _
         _el.jHueTableExtender({
           fixedHeader: true,
           includeNavigator: false,
-          parentId: snippet.id()
+          parentId: 'snippet_' + snippet.id(),
+          clonedContainerPosition: "absolute"
         });
       });
     });

desktop/core/src/desktop/static/desktop/js/jquery.tableextender.js

@@ -191,8 +191,14 @@
     var clonedTableContainer = $("<div>").width($(plugin.element).outerWidth());
     clonedTable.appendTo(clonedTableContainer);
 
-    var clonedTableVisibleContainer = $("<div>").attr("id", $(plugin.element).attr("id") + "jHueTableExtenderClonedContainer").addClass("jHueTableExtenderClonedContainer").width($(plugin.element).parent().width()).css("overflow-x", "hidden").css("top", ($(plugin.element).parent().offset().top - $(window).scrollTop()) + "px");
-    clonedTableVisibleContainer.css("position", "fixed");
+    var topPosition;
+    if (plugin.options.clonedContainerPosition == 'absolute') {
+      topPosition = $(plugin.element).parent().position().top - $(window).scrollTop();
+    } else {
+      topPosition = $(plugin.element).parent().offset().top - $(window).scrollTop();
+    }
+    var clonedTableVisibleContainer = $("<div>").attr("id", $(plugin.element).attr("id") + "jHueTableExtenderClonedContainer").addClass("jHueTableExtenderClonedContainer").width($(plugin.element).parent().width()).css("overflow-x", "hidden").css("top", topPosition + "px");
+    clonedTableVisibleContainer.css("position", plugin.options.clonedContainerPosition || "fixed");
 
     clonedTableContainer.appendTo(clonedTableVisibleContainer);
     clonedTableVisibleContainer.prependTo($(plugin.element).parent());