SpreadsheetClientSideEventsBuilder.OnBeforeSend(String) Method

Specifies a function used to customize a web request before it is sent to an action handler.

Namespace: DevExpress.AspNetCore.Spreadsheet

Assembly: DevExpress.AspNetCore.Spreadsheet.v25.1.dll

NuGet Package: DevExpress.AspNetCore.Spreadsheet

Declaration

public SpreadsheetClientSideEventsBuilder OnBeforeSend(
    string callback
)

Parameters

Name	Type	Description
callback	String	A JavaScript function.

Returns

Type	Description
SpreadsheetClientSideEventsBuilder	A reference to this instance after the method is called.

Remarks

Use this method to register a client-side handler for the Spreadsheet control’s beforeSend event. The handler can be a reference to an external function or an inline function text:

Reference

<script>
function spreadsheet_beforeSend(spreadsheet, e) {
    /* ... */
}
</script>

@(Html.DevExpress()
    .Spreadsheet("spreadsheet")
    .DocumentRequestHandlerUrl(Url.Page(pageName: null, pageHandler: "DxSpreadsheetRequest"))
    .ClientSideEvents(events =>
        events.OnBeforeSend("spreadsheet_beforeSend")
    )
)

Inline Function

@(Html.DevExpress()
    .Spreadsheet("spreadsheet")
    .DocumentRequestHandlerUrl(Url.Page(pageName: null, pageHandler: "DxSpreadsheetRequest"))
    .ClientSideEvents(events =>
        events.OnBeforeSend(@<text>
            function(spreadsheet, e) {
                /* ... */
            }
        </text>)
    )
)

The function receives the following arguments:

• The client-side Spreadsheet object instance.
• An object that contains event arguments. Use the object’s request property to access and modify the underlying XMLHttpRequest (for example, add headers).

The following code snippet adds an anti‑forgery token to every internal request the Spreadsheet sends to the request handler (controller action):

@inject Microsoft.AspNetCore.Antiforgery.IAntiforgery Antiforgery

<script>
function spreadsheet_beforeSend(spreadsheet, e) {
    e.request.setRequestHeader("RequestVerificationToken",
                                "@Antiforgery.GetAndStoreTokens(Context).RequestToken");
}
</script>

@(Html.DevExpress()
    .Spreadsheet("spreadsheet")
    .DocumentRequestHandlerUrl(Url.Page(pageName: null, pageHandler: "DxSpreadsheetRequest"))
    .ClientSideEvents(events =>
        events.OnBeforeSend("spreadsheet_beforeSend")
    )
)