RadComboBox can not show any loading.. information when only dropdownlist is opene

[ari]

So

There is no feature to show any loading information  when you open combo's drop down list
Or i did not found any..

there is loadingmessage feature but it works only when something was written to combo..

So how I can inform user that there is loading.. when only drop down list was opened ?

Thanks any help

[ari]

Hi

Any information how to solve this problem..?

thanks for help

[Helen]

Hi,

Probably you will find helpful the following demo:

http://demos.telerik.com/aspnet-ajax/ajax/examples/loadingpanel/explicitshowhide/defaultcs.aspx

Yo may subscribe to the OnClientDropDownOpening/Opened and show the loading panel.

Regards,
Helen
the Telerik team

[Tim]

The thing is, this worked with the 2011-Versions. Just since the 2012 Versions this issue occures.
Here is also one of your examples where this works as expected
http://demos.telerik.com/aspnet-ajax/combobox/examples/functionality/clienttemplates/defaultcs.aspx

When the box is opened the first time and the content is loaded a loading message appears.

While in this example, it has the bug again:
http://demos.telerik.com/aspnet-ajax/combobox/examples/programming/clientevents/defaultcs.aspx

[Tim]

I think I found the Bug.
It happens in the function  "$T.RadComboBox.prototype._positionDropDown" in the file "RadComboBox.DropDown.js".

In the 2012 versions an item will be added and removed. A variable for the item is declared inside an if-block and than removed outside (where it isn't declared). 
Whatever is the bug, the "Loading ..."-message appears when this code is replaced with its old state.

[Ivana]

Hi Tim,

Yes, your observations are right. I have inspected the described scenario and the problem comes from the piece of code you have specified.
I have logged this as a bug and we will do our best to fix. Here is the URL to the PITS item: http://www.telerik.com/support/pits.aspx#/public/aspnet-ajax/12666.

Thank you for your report. Your telerik points have been updated.

Regards,
Ivana
the Telerik team

[Chris]

Hi Ivana,
Is there a suggested workaround until this gets fixed in an SP? We just upgraded from a 2011 release to 2012 Q3 and this is a big usability problem since our combobox can take several seconds to populate data. 

Thanks,
Chris

[Chris]

FYI, here is the script I came up with to restore the initial "Loading..." indicator:

function onClientDropDownOpened(sender, eventArgs) {
    var a = $("#" + sender.get_id() + "_DropDown").find(".rcbScroll");
    if (a.html().length == 0)
        a.html("<ul><li class='rcbLoading'>Loading...</li></ul>");
}

[Nencho]

Hello Chris,

I will forward the suggestion to our development team for further consideration. In addition, we would need a bit more time in order to provide you a proper workaround for the desired functionality.

Kind regards,
Nencho
the Telerik team

[Chris]

Thanks Nencho, my workaround was really intended for other users who are currently facing this issue. I am sure you guys will get it fixed permanently in a future SP.

[Nencho]

Hi Chris,

Please consider using the following workaround, in order to achieve the desired functionality with a proper rendering:

function OnClientItemsRequesting(sender, eventArgs) {
         alert(1)
         $telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbScroll").prepend("<div id=\"RadComboBox1_LoadingDiv\" class=\"rcbLoading\">Loading...</div>")
     }
     function OnClientItemsRequested(sender, eventArgs) {

         $telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbLoading").remove();

     }

All the best,
Nencho
the Telerik team

[Elena]

Hello Nencho,
I tried the workaround and it works on initial load (first OnClientItemsRequesting) but subsequent requests might result in multiple 'Loading...' messages. How can I check programmatically if 'Loading..' is already there and skip the prepend?

[Dimitar Terziev]

Hi Elena,

In order to ensure that there will be no duplicating div elements you could always call the following code before the prepend of the div with the loading message:

$telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbLoading").remove();

All the best,
Dimitar Terziev
the Telerik team

[Elena]

Hi Dimitar,

This was one of the first things I tried, but it does not help. Looks like you add the 'Loading...' after OnClientItemsRequesting.
I used the code posted by Chris where he checks for html().length and this works better, as html is empty on initial load only.
Now, it appears that I have some columns where a.html() is null. For these columns the prepend() does not work. So again, there is no Loading... indicator when the combobox first opens (work normally for subsequent requests).

 

function OnClientItemsRequesting(sender, eventArgs) {
    var a = $telerik.$("#" + sender.get_id() + "_DropDown").find(".rcbScroll");

    if (a.html() != undefined) {
        if (a.html().length == 0)
            a.prepend("<div id=\"RadComboBox1_LoadingDiv\" class=\"rcbLoading\">Loading...</div>")
    }
}

 

Do you have another workaround for this problem (internally you must be doing something different since it works regardless of a.html())?
Do you have an idea what might cause a.html() to be null?

[Helen]

Hello all,

There was such a bug, which is solved in the latest Q3 SP1 release:

http://demos.telerik.com/aspnet-ajax/combobox/examples/populatingwithdata/autocompletesql/defaultcs.aspx


Regards,
Helen
the Telerik team