ListView, Paging and SortOrder

[Jürgen]

Hello there!

I'm facing a very strange behaviour.

I'm using RadListView to display products on our Sitefinity-Website. The RadListView its bound to his data with NeedDataSource. The DataSource itself returns the products in right oder (sorted by name). While displaying the products in RadListView all in one time, it's working fine, but when I set AllowPaging=true, the items are not sorted any more by name. I don't know which field they are sorted by. I don't use any buttons oder code-behind to set a different sort expression and I'm sure that this behaviour is new, since one of the last updates of Sitefinity.

Version 3.7 SP4 for .NET 4

Has anyone an idea or has been facing a similar problem?

Thanks in advance!

Dieter

[Iana Tsolova]

Hello Dieter,

Can you try reproducing the problem in a simple web page outside Sitefinity?
However, I need to mention that RadListView displayed the records as they are present in its data source. It does not perform any additional actions on its data source internally.

Let me know how it goes.

Greetings,
Iana
the Telerik team

[JM]

I'm experiencing the same thing.

[Eric]

Hi I am experiencing the same thing.

I have a RadListView with a RadDataPager and when I set AllowPaging to false and sort the data bound to RadListView manually it works as expected. But when I set AllowPaging to true although the data that I bind to RadLisView is in correct order in ItemDataBound I get the DataItems as if the data is not sorted at all.

protected void news_NeedDataSource(object sender, Telerik.Web.UI.RadListViewNeedDataSourceEventArgs e)
{
    NewsManager manager = new NewsManager();
    foreach (SortFieldView view in SortByList)
    {
        if (view.SortDirection != SortDirection.None)
        {
            manager.AddSortField(view.SortField, view.SortDirection);
        }
    }
    var newsList = manager.GetNews();

    List<NewsItem> list = newsList.ToList();
    news.DataSource = list;
}

protected void news_ItemDataBound(object sender, Telerik.Web.UI.RadListViewItemEventArgs e)
{
    if (e.Item.ItemType == Telerik.Web.UI.RadListViewItemType.DataItem ||
       e.Item.ItemType == Telerik.Web.UI.RadListViewItemType.AlternatingItem)
    {
        RadListViewDataItem viewItem = (RadListViewDataItem)e.Item;
        NewsItemControl newsItemControl = (NewsItemControl)e.Item.FindControl("newsItem");
        NewsItem news = (NewsItem)viewItem.DataItem;

        newsItemControl.Update(news);
    }
}

<telerik:RadListView ID="news" runat="server"
    onitemdatabound="news_ItemDataBound"
    onneeddatasource="news_NeedDataSource" AllowPaging="true">
    <ItemTemplate>
        <uc2:NewsItemControl ID="newsItem" runat="server" />
    </ItemTemplate>
</telerik:RadListView>
    <telerik:RadDataPager ID="pager" runat="server"
        PagedControlID="news" PageSize="4" EnableEmbeddedSkins="false">
        <Fields>
            <telerik:RadDataPagerTemplatePageField HorizontalPosition="RightFloat" >
                <PagerTemplate>
                    <asp:LinkButton Visible="<%# Container.Owner.StartRowIndex == 0 ? false : true %>"
                        ID="btnPrev" runat="server" CommandName="Page" CommandArgument="Prev">< Newer</asp:LinkButton>
                    <asp:LinkButton Visible="<%# Container.Owner.TotalRowCount < Container.Owner.StartRowIndex+Container.Owner.PageSize ? false : true %>"
                        ID="btnNext" runat="server" CommandName="Page" CommandArgument="Next">Older ></asp:LinkButton>
                </PagerTemplate>
            </telerik:RadDataPagerTemplatePageField>
            <telerik:RadDataPagerTemplatePageField HorizontalPosition="RightFloat"  >
                <PagerTemplate>
                    <asp:Label runat="server" ID="CurrentPageLabel" Text="<%# Container.Owner.StartRowIndex+1%>" />
                    to
                    <asp:Label runat="server" ID="TotalPagesLabel" Text="<%# Container.Owner.TotalRowCount < Container.Owner.StartRowIndex+Container.Owner.PageSize ?
                    Container.Owner.TotalRowCount : Container.Owner.StartRowIndex+Container.Owner.PageSize %>" />
                    of
                    <asp:Label runat="server" ID="TotalItemsLabel" Text="<%# Container.Owner.TotalRowCount%>" />
                    <br />
                </PagerTemplate>
            </telerik:RadDataPagerTemplatePageField>
        </Fields>
    </telerik:RadDataPager>

Thank you...

[Iana Tsolova]

Hello,

Is the issue you are facing available in a simple web site? Can you share it or some code where we can observe the problem?

Kind regards,
Iana
the Telerik team

[Eric]

Hi Iana,

The problem occurs if I use ADO.NET Entity Model as a data source, if I use regular classes and Lists it doesn't happen.

I attached a sample solution to my support ticket named "Sorting Problem with AllowPaging enabled".

Thank you...

[Iana Tsolova]

Hi Eric,

I will check the sample you provided and turn back to you with my findings.
In the meanwhile, can you try the same scenario with ASP:ListView so we can further isolate the issue?

Best wishes,
Iana
the Telerik team

[Eric]

It works with ASP:ListView.

Note: In order to make ASP:ListView paging work with RadDataPager I had to convert the data source to a list by using ToList() method of IQueryable<T>. I also did the same in the RadListView need data source but it didn't work for RadListView.

Thank you...

[Iana Tsolova]

Hi Eric,

I tested the project provided in the support thread and here are my findings:

After further debugging it appeared the issue is due to a limitation in the Entity Framework. In order allow paging, e.g. to be able to call the Skip() and Take() methods, the list of records should be sorted. Therefore the RadListView is sorting the data source is sorted by the first data field. However I have forwarded the issue to our developers and they will change the listview behavior so sorting will work with page if the sorting is performed through the listview API, i.e. is sort expressions are added to it. In this case the sorting will be still performed at database level but the listview will pass the sort expressions to it for you.

Regards,
Iana
the Telerik team

[James B.]

Thought I'd mention I just found out about this issue today as well.

This is a normal asp.net site where we upgraded the telerik components recently. I've done built in paging with a radlistview with older versions of telerik that work just fine. So guessing this is a recent issue.

[Iana Tsolova]

Hi James,

Thank you for sharing your finding with us and with the community. We will take them into account in performing further investigation and addressing the issue.

Greetings,
Iana
the Telerik team

[Tom]

Hello,

I have just encountered this problem too. Do you know if it is now fixed? or is there a workaround i can use?

[Iana Tsolova]

Hello,

The issue is already fixed. If you are using the latest version you should not experience the behavior discussed in this thread.

Regards,
Iana Tsolova
the Telerik team

[Colin Wright]

I am experiencing this issue and I am using the very latest version of Telerik Controls

[Angel Petrov]

Hi Colin,

I have already provided an answer in the official support ticket you have opened regarding this matter. As soon as we finish investigating the problem you can share your findings here thus helping other community members overwhelm such type of problems.

Regards,
Angel Petrov
Telerik