In order to reject specific changes during redaction process or to keep a full log of changes in the document, you need to set Redactor.RedactionCallback property, to a class implementing IRedactionCallback interface. The interface contains only one method, AcceptRedaction, which receives detailed information about proposed redaction and returns Boolean value, accepted or not.
Below, we create a callback class, dumping changes to system console:
public class RedactionDump implements IRedactionCallback { public RedactionDump() { } public boolean acceptRedaction(RedactionDescription description) { System....Conversion Product Solution GroupDocs.Comparison Product Solution GroupDocs...