Using Callbacks

• Jun 11, 2020
• 7 minutes to read

Some DevExpress MVC extensions can work in callback mode by requesting the server via their own callbacks. Using callbacks is an efficient way to load/update extension content on demand (to minimize the initial data transfer) or to perform some lengthy functional operations (such as file uploads).

The following requirements should be met for an extension that is used in callback mode.

• An extension should be defined in a separate Partial View (.cshtml or .vbhtml).

• A Controller should contain an additional Action method to handle extension callbacks and route them directly to a Partial View containing the extension. This allows the extension render to be conditionally updated in response to the end-user action performed.

• Callback routing logic should be defined using a CallbackRouteValues property of an extension’s settings object. This property allows the names of the callback handling Controller and Action to be specified.

Note that these requirements are not required for all extensions that support the use of callbacks. For instance, the UploadControl extension might not be declared within a Partial View - it is enough for it to properly implement a callback handler Action method and reference this method in the CallbackRouteValues property’s value.

Extensions That Can Use Callbacks

The table below lists DevExpress MVC extensions that support the use of callbacks.

|

Extension

|

Callback Mode Availability

|

Requirements for Callback Mode Realization

| | --- | --- | --- | |

Calendar

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (CalendarSettings.CallbackRouteValues)

| |

CallbackPanel

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (CallbackPanelSettings.CallbackRouteValues)

| |

Charting

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (ChartControlSettings.CallbackRouteValues)

| |

ComboBox

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (AutoCompleteBoxBaseSettings.CallbackRouteValues)

| |

DataView

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (DataViewSettings.CallbackRouteValues)

| |

DateEdit

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (DateEditSettings.CallbackRouteValues)

| |

DockManager

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (DockManagerSettings.CallbackRouteValues)

| |

DockPanel

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (PopupControlSettingsBase.CallbackRouteValues)

| |

Gantt

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (GanttSettings.CallbackRouteValues)

| |

GridView

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (GridSettingsBase.CallbackRouteValues)

| |

HtmlEditor

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (HtmlEditorSettings.CallbackRouteValues)

| |

ListBox

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (ListBoxSettings.CallbackRouteValues)

| |

Menu

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (MenuSettings.CallbackRouteValues)

| |

NavBar

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (NavBarSettings.CallbackRouteValues)

| |

PageControl

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (PageControlSettings.CallbackRouteValues)

| |

PivotGrid

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (PivotGridSettings.CallbackRouteValues)

| |

PopupControl

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (PopupControlSettingsBase.CallbackRouteValues)

| |

PopupMenu

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (PopupMenuSettings.CallbackRouteValues)

| |

RichEdit

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (RichEditSettings.CallbackRouteValues)

| |

Scheduler

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (SchedulerSettings.CallbackRouteValues)

| |

Spreadsheet

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (SpreadsheetSettings.CallbackRouteValues)

| |

TreeList

|

Always

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (TreeListSettings.CallbackRouteValues)

| |

TreeView

|

Optional

|

Define extension in a separate Partial View.

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (TreeViewSettings.CallbackRouteValues)

| |

UploadControl

|

Optional

|

Implement an Action method within the Controller to handle extension callbacks.

Specify the Controller and Action names via the CallbackRouteValues property. (UploadControlSettings.CallbackRouteValues)

|

jQuery AJAX callbacks

Note

DevExpress supports jQuery AJAX callbacks starting with v12.1. For older versions, you can use the How to load MVC extensions using the CallbackPanel extension example.

The following example illustrates how to load a GridView to a div element on a callback.

• JS
• ASPX

function OnClick(s, e) {
    $.ajax({
        type: "POST",
        url: "@Url.Action("GridViewPartial")",
        success: function(response) {
            $("#container").html(response);
        }
    });
}

@Html.DevExpress().Button(settings => {
    settings.Name = "MyButton";
    settings.Text = "Click Me!!!";
    settings.ClientSideEvents.Click = "OnClick";
}).GetHtml()

<div id="container" class="container">
</div>

Online Demo

jQuery AJAX Callbacks

Online Example

How to use the jQuery.ajax function with DevExpress MVC Extensions

Example

This example demonstrates how the use of callbacks can be implemented for the TreeView extension.

View Code - “Callbacks” (ASPX)

• C#

<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="indexContent" ContentPlaceHolderID="ContentHolder" runat="server">
    <% 
        Html.RenderPartial("CallbacksPartial");
    %>
</asp:Content>

View Code - “Callbacks” (Razor)

• C#

@Html.Partial("CallbacksPartial")

PartialView code - “CallbacksPartial” (ASPX):

• C#

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %>

<% 
    Html.DevExpress().TreeView(
        settings =>
        {
            settings.Name = "tvCallbacks";
            settings.CallbackRouteValues = new { Controller = "TreeView", Action = "CallbacksPartial" };
        })
        .BindToSiteMap("~/App_Data/Feature.sitemap", false)
        .Render();
%>

PartialView code - “CallbacksPartial” (Razor):

• C#

@Html.DevExpress().TreeView(
    settings =>
    {
        settings.Name = "tvCallbacks";
        settings.CallbackRouteValues = new { Controller = "TreeView", Action = "CallbacksPartial" };
    }).BindToSiteMap("~/App_Data/Feature.sitemap", false).GetHtml()

Controller (“TreeViewController”):

• C#

public class TreeViewController: Controller {

        public ActionResult Callbacks() {
            return DemoView("Callbacks");
        }

        public ActionResult CallbacksPartial() {
            return PartialView("CallbacksPartial");
        }

    }

See Also

Passing Values to a Controller Action through Callbacks