Multiple Postback onRadClientDataSource when WebServiceDataSourceSettings has no items

[Kuya]

Hi! We have had this problem for quite some time now.We have this code:

 <telerik:RadClientDataSource ID="csDsInprog" runat="server" EnableServerPaging="false" EnableServerSorting="false" AllowPaging="false" ClientEvents-OnCustomParameter="ParameterMap" EnableViewState="false"
              ClientEvents-OnRequestEnd="showInProgressGrid">
              <DataSource>
                <WebServiceDataSourceSettings>
                  <Select Url="/user/history/Default.aspx/GetHistoryInProg" RequestType="POST" DataType="JSON" ContentType="application/json" />
                </WebServiceDataSourceSettings>
              </DataSource>
              <Schema DataName="d">
              </Schema>
            </telerik:RadClientDataSource>

 

This is the ClientDataSourceID for a radgrid. However, when there are no records returned by the URL, we see that it does multiple postbacks. If it does return information, it does the postback only once.

 

Can you help us with this one? We have updated to the latest version of the UI but still it has the same error.

[Kuya]

Further debugging-

we have a clientside ".rebind()". When a button is clicked, it does the rebind of the radgrid with the above datasource.

It seems the problem is with the rebind() part. 

[Kuya]

Confirmed. It is happening when mastertable.rebind() is executed on client side, and datasource is from a RadClientDataSource.

Steps to reproduce:

1. Create a page with basic radgrid and RadClientDataSource (post, json) 
2. On the webmethod for the RadClientDataSource, return empty list of data
3. On browser, trigger the client-side rebind and check the "network" tab
4. You will see multiple calls to the URL 

<With Data> 
5. Modify your webmethod to return at least 1 data
6. Go back to browser, and trigger rebind. Then check the "network" tab again.
7. URL will be called only once

[Eyup]

Hello Kuya,

There was a similar bug:
https://feedback.telerik.com/Project/108/Feedback/Details/214763-grid-with-radclientdatasource-sends-two-requests-when-navigating-with-grid-pager

You can try to enable ServerPaging, Sorting and Filtering to check whether this will resolve the issue.

Regards,
Eyup
Progress Telerik

[Kuya]

Hi! Thanks for the response. Unfortunately, this is still happening. If I use AllowServerPaging, it gets worse. If I rebind, it posts 3 times even if there is data in the response.

[Eyup]

Hello Kuya,

 

In this case, you can try the following options:

1. Ensure that you are using the latest release version of the controls.

2. If there is AJAX enabled on the page, temporarily disable it and check for client-side errors:
https://www.telerik.com/support/kb/aspnet-ajax/ajaxmanager/details/get-more-descriptive-errors-by-disabling-ajax

3. If the previous steps do not resolve the issue, you can open a formal support thread and send us a very basic isolated runnable web site demonstrating the issue so we can reproduce it locally and take a closer look.

 

Regards,
Eyup
Progress Telerik

[Kuya]

Thanks Eyup, let me do that and get back.

[Kuya]

Hi Everyone, issue is still occurring. Can you kindly help us out?

[Peter Milchev]

Hello Kuya,

Please try to replicate the issue in the project attached to the feedback portal item where no duplicate requests are observed:

• https://feedback.telerik.com/aspnet-ajax/1377274-grid-with-radclientdatasource-sends-two-requests-when-navigating-with-grid-pager 

Regards,
Peter Milchev
Progress Telerik