Document Viewer Requirements and Limitations

• Jul 17, 2024
• 2 minutes to read

Document Viewer Requirements

Required Libraries

Web Reporting components require DevExtreme and third-party libraries, which you can register automatically. To do this, add the resources section to the application’s Web.config file:

XML

<devExpress>
    <!-- ... -->
    <resources>
        <add type="ThirdParty" />
        <add type="DevExtreme" />
    </resources>
</devExpress>

For manual registration, review the following help topic: Client Script Libraries.

Register HTTP Handlers

Register ASPxHttpHandlerModule (DXXRDV.axd) in the web.config file as a module to process resources and as a handler to process data.

The ASPxHttpHandlerModule is automatically registered in this file in the following cases:

• When you use DevExpress project templates to create an application with reporting controls;
• When you use the Insert DevExpress MVC Extension Wizard to add MVC reporting extensions.

If you create the Document Viewer in code, you should register ASPxHttpHandlerModule explicitly. Insert the declarations in the system.web/httpModules and system.webServer/modules configuration sections, and add the handler registration to the system.web/httpHandlers and system.webServer/handlers sections.

XML

<system.web>
...
  <httpHandlers>
    ...
    <add type="DevExpress.Web.ASPxHttpHandlerModule, DevExpress.Web.v24.1, Version=24.1.7.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" 
         verb="GET,POST" path="DXXRDV.axd" validate="false" />
  </httpHandlers>  
  <httpModules>
    <add type="DevExpress.Web.ASPxHttpHandlerModule, DevExpress.Web.v24.1, Version=24.1.7.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" name="ASPxHttpHandlerModule" />
  </httpModules>
</system.web>
<system.webServer>
  <handlers>
    ...
    <add type="DevExpress.Web.ASPxHttpHandlerModule, DevExpress.Web.v24.1, Version=24.1.7.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" 
         verb="GET,POST" path="DXXRDV.axd" name="ASPxWebDocumentViewerHandlerModule" preCondition="integratedMode" />
  </handlers>
  <modules runAllManagedModulesForAllRequests="true">
    <add type="DevExpress.Web.ASPxHttpHandlerModule, DevExpress.Web.v24.1, Version=24.1.7.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" name="ASPxHttpHandlerModule" />
  </modules>
</system.webServer>

The Document Viewer validates the configuration and displays the following error message if the handler is not registered.

“The DXXRDV.axd handler is not registered in the web.config (section: system.webServer/handlers). To disable web.config validation, use the DevExpress.Web.Mvc.WebDocumentViewerSettings.DisableHttpHandlerValidation property.“

Do not use handlers and/or validate their registration in the following cases:

• You use custom HTTP handlers or MVC controllers to process requests.
• Handlers are registered in the <location> section, and automatic validation fails.

To disable automatic handler validation, set the WebDocumentViewerSettings.DisableHttpHandlerValidation option to true:

C#

@Html.DevExpress().WebDocumentViewer(settings => {
    settings.Name = "WebDocumentViewer";
    settings.DisableHttpHandlerValidation = true;
}).Bind(Model.Report).GetHtml();

VB.NET

@Html.DevExpress().WebDocumentViewer(Function(settings) 
    settings.Name = "WebDocumentViewer"
    settings.DisableHttpHandlerValidation = True
End Function).Bind(Model.Report).GetHtml()

Document Viewer Limitations

• The following document formats do not support export to multiple files:

  • HTML;
  • Image;
  • XLS;
  • XLSX.

  You can export a report to any of these formats as a single file or as a single file page-by-page (one file that contains multiple pages).

• The Document Viewer prints a report by converting it to PDF and printing the PDF. This approach requires browser support for PDF.