Implements a callback to set cached field values.
Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
To speed up rendering of field controls on non-Display form pages, you can implement a callback that caches the values. For security reasons, this callback can be used in Display mode only, and cannot be called for certain field controls (for example, for a Lookup field to a security-trimmed list). It is best practice to avoid setting callbacks for draft versions or for pages that are checked out.