The ASPxWebDocumentViewer control provides an advanced client-side API in addition to the comprehensive server-side object model. This enables web applications based on this control to function more efficiently using a combination of server-side and client-side processing. The ASPxClientWebDocumentViewer is this control's client-side equivalent.
Although the entire client API is available on the client side, we recommend that you only use the documented public client-side API for any custom client functionality. The undocumented API can be changed or removed without any notifications, and applications using this API can stop working correctly after upgrading to a newer reporting controls version.