createGrouped bug?

Question

Hi all,

I am doing an app with a datasource created from an array. I picked some bits here and there to make this work.

var groupDataSource = AppData.groupedItemsSubset().createGrouped(this.groupKeySelector, this.groupDataSelector, this.groupSorter).groups;
ui.setOptions(listView, {
      itemDataSource: AppData.groupedItemsSubset().dataSource,
      itemTemplate: itemTemplate,
      groupDataSource: groupDataSource.dataSource,
      layout: new ui.GridLayout({ groupHeaderPosition: "top" })
});

The problem is, when I specify the groupSorter parameter (3rd in createGrouped), my items are not only unsorted, but some of my groups are mixed up and the group headers are missing.

Any ideas? The docs seem to support this :

http://msdn.microsoft.com/en-us/library/windows/apps/hh700742.aspx

Answer 1

Hi Pedro,

I think the problem is the sorting is only happening in the Binding.List instance you created for groupDataSource. Perhaps try refactoring your code slightly:

var data = AppData.groupedItemsSubset.groupDataSource.createGrouped(this.groupKeySelector, this.groupDataSelector, this.groupSorter);
 ui.setOptions(listView, {
       itemDataSource: data.dataSource,
       itemTemplate: itemTemplate,
       groupDataSource: data.groups.dataSource,
       layout: new ui.GridLayout({ groupHeaderPosition: "top" })
 });

Cheers,

-Jeff

Answer 2

Thank you. I did have a bug elsewhere. My subset was already a grouped dataset and it was confusing things.

Still, your post was useful. Thanks.