Combox performance auto complete and combo in textbox mode

[khurram]

Hi,

I am using combox which is loaded via webservice on demand. I am noticing that its very slow. From the moment i type something in a combo till it reaches webservice at server there is a delay of around 3 seconds. Even the "Loading.." text is not shown rapidly. 

Here is the code:

<telerik:RadComboBox ID="radList" Runat="server" EnableEmbeddedSkins="False" Skin="search" Width="120px" NoWrap="True" Height="200px" DropDownWidth="225px" EnableLoadOnDemand="true"
OnClientItemsRequesting="OnClientItemsRequesting" ItemRequestTimeout="2000"
OnClientSelectedIndexChanged="onChanged"
EnableViewState="false" LoadingMessage="Loading..." EmptyMessage="Type to get results"
>

<WebServiceSettings Method="GetItems" Path="~/WebServices/Search.asmx" />
</telerik:RadComboBox>

And the javascript function called:

function OnClientItemsRequesting(sender, eventArgs)

{


var text = eventArgs.get_text();

if( text.length < 3)

{

eventArgs.set_cancel(true);

}

else{

var context = eventArgs.get_context();

context["FilterString"] = text;

}
}

This is the only thing that I do for defining the conotrol. Is there any way to improve the perfomance, as 3  seconds just to get to server is really slow.

My second question is there a way to change mode of combo to textbox?

Thanks in advance for your help.

Best regards,

Khurram

[Veselin Vasilev]

Hello khurram,

It is really strange that you get such a delay. Do you experience the same problem in our online demo?

Can you explain in more detail what do you mean by "to change mode of combo to textbox" ?


All the best,
Veskoni
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[khurram]

Hi,
thanks for your reply. I have checked your demo online and its working fine. I will try to investigate more what could be causing it.

As far as textbox mode is concerned; I had liked to display a combo list as a textbox so that the user cannot open it and has to type to get the list. Something like ajax toolkit autocomplete but with text, value selection.

http://www.asp.net/AJAX/AjaxControlToolkit/Samples/AutoComplete/AutoComplete.aspx

Regards,
Khurram

[Veselin Vasilev]

Hello khurram,

To hide the dropdown image you can set the ShowToggleImage property to False.
To open the dropdown only when the user types a number of letters please see this article:
Requesting items when a given number of letters are entered


Sincerely yours,
Veskoni
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[khurram]

Hi,
I finally found what cas causing the delay. If you set timeout request value it adds a considerable delay.
Regards,
Khurram

[rtk]

Is it possible to not show the dropdownlist before i have enter a number of letters.

This only prevent filling the dropdownlist before 3 letters are typed in.

function OnClientItemsRequestingHandler(sender, eventArgs)
{
   if (sender.get_text().length < 3)
   {
       eventArgs.set_cancel(true);
   }

I would like it to look just like a textbox, until i have enter 3 letters. Maybe i should use another methods?

[Veselin Vasilev]

Hi brajoh,

You can use the same method to cancel the OnClientDropDownOpening event.

I hope this helps.

All the best,
Veselin Vasilev
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[rtk]

Thaks, now i just need to clear the dropdownlist on clientside. If the number of letters get smaller than 3, i need to clear and hide the dropdownlist.

And is it possible to insert a row on clientside and make this selected.

[Veselin Vasilev]

Hi brajoh,

For the first questions - you can subscribe to the OnClientKeyPressing event and hide the dropdown using the client-side API of the combobox.

And yes, it is possible to add a new item in the combobox client-side. Please check this demo:
Add/Remove/Disable items

Sincerely yours,
Veselin Vasilev
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[mark baer]

If a request is taking a long time, is there a way to cancel it clientside?  Does it need to be done server side?  Is there a way you recommend we handle this?

thanks

[Nencho]

Hello Mark,

You could achieve this functionality, by canceling the OnClientItemsRequesting client-side event, or handling the OnClientItemsRequestFailed if any error has occurred while loading elements using the load-on-demand mechanism.

All the best,
Nencho
the Telerik team