AJAX Page - Callback Panel - How It Works

OboutInc.oboutAJAXPage namespace
<%@ Register TagPrefix="oajax" Namespace="OboutInc" Assembly="obout_AJAXPage" %>


<oajax:CallbackPanel runat="server" ID="callbackPanel1">
some content
Loading...please wait

CallbackPanel has 2 elements:
  • content element can contain contain html, js, css and other server controls - like Obout Calendar, Obout EasyMenu, ASP.NET controls (ASP Textbox, ASP DropDownList, etc.).

  • loading element is optional and it can include the html to display while the panel is loading.
    If ommited, a default "Loading..." text is shown and all styles from content element are applied to the loading element.
    It is visible only when the callback panel is updated using client-side UpdatePanel method.
Both content and loading elements can contain style definitions.

<oajax:CallbackPanel runat="server" ID="callbackPanel1">

<content style="border:1px solid gray;width:400px;height:200px">

some content


<loading style="border:1px solid red;width:400px;height:200px">

Loading...please wait



It is very useful to load dynamic scripts, dynamic stylesheets, dynamic controls, etc.

The update of the panel is done without reloading the page.

Client-side update
ob_post.UpdatePanelInContainer("callbackPanel1", "container");
ob_post.UpdatePanelFromPage("callbackPanel1", "container", "callbackPanels.aspx");

Server-side update
UpdatePanel("callbackPanel1", "container");

View UpdatePanel tutorial.
View UpdatePanelInContainer tutorial.
View UpdatePanelFromPage tutorial.
View UpdateAllPanels tutorial.