Redaction basics

GroupDocs.Redaction supports an effective set of document redaction features. It allows to apply redactions for text, metadata, annotations, images.

Wide range document formats is supported: PDF, DOC, DOCX, PPT, PPTX, XLS, XLSX and others. See full list of supported formats at supported document formats article

Redaction types

GroupDocs.Redaction comes with the following redaction types:

TypeDescriptionClasses
TextReplaces or hides with color block a portion of text within document bodyExactPhraseRedaction, RegexRedaction
MetadataReplace metadata values with empty ones or redacts metadata textsEraseMetadataRedaction, MetadataSearchRedaction
AnnotationsDeletes annotations from document or redacts its textsDeleteAnnotationRedaction, AnnotationRedaction
ImagesReplaces specific area of an image with a colored boxImageAreaRedaction

Apply redaction

Applying redaction to a document is done through Redactor.Apply method. As a result, you receive RedactorChangeLog instance, containing a log entry for each redaction applied. The entry contains reference to Redacton instance including its options, status of the operation (see below) and textual descriptions when applicable. If at least one redaction failed, you will see Status == RedactionStatus.Failed:

C#

using (Redactor redactor = new Redactor("sample.docx"))
{
   RedactorChangeLog result = redactor.Apply(new ExactPhraseRedaction("John Doe", new ReplacementOptions("[personal]")));
   if (result.Status != RedactionStatus.Failed)
   {
      redactor.Save();
   };
}

All possible statuses of the RedactionStatus enumeration are listed in this table:

StatusDescriptionPossible reasons
AppliedRedaction was fully and successfully appliedAll operations within redaction process were successfully applied
PartiallyAppliedRedaction was applied only to a part of its matches1) Trial limitations for replacements were exceeded2) At least one change was rejected by user
SkippedRedaction was skipped (not applied)1) Trial limitations for redactions were exceeded2) Redaction cannot be applied to this type of document3) All replacements were rejected by user and no changes were made
FailedRedaction failed with exceptionAn exception occurred in process of redaction

For detailed information you have to iterate through redaction log entries in RedactorChangeLog.RedactionLog and check for ErrorMessage property of any items with status other than Applied:

C#

RedactorChangeLog summary = redactor.Apply( ... );
if (summary.Status != RedactionStatus.Applied)
{
	for (int i = 0; i < summary.RedactionLog.Count; i++)
	{
		RedactorLogEntry logEntry = summary.RedactionLog[i];
    	if (logEntry.Result.Status != RedactionStatus.Applied)
        {
			Console.WriteLine("{0} status is {1}, details: {2}", 
				logEntry.Redaction.GetType().Name, 
				logEntry.Result.Status, 
				logEntry.Result.ErrorMessage);
		}
	}
}

Apply multiple redactions

You can apply as much redactions as you need in a single call to Redactor.Apply method, since its overload accepts an array of redactions and redaction policy. In this case, redactions will be applied in the same order as they appear in the array. As an alternative to specifying redaction sets in your code, you can create an XML file with redaction policy, as described here.

C#

using (Redactor redactor = new Redactor("sample.docx"))
{
   var redactionList = new Redaction[] 
   {
      new ExactPhraseRedaction("John Doe", new ReplacementOptions("[Client]")),
      new RegexRedaction("Redaction", new ReplacementOptions("[Product]")),
      new RegexRedaction("\\d{2}\\s*\\d{2}[^\\d]*\\d{6}", new ReplacementOptions(System.Drawing.Color.Blue)),
      new DeleteAnnotationRedaction(),
      new EraseMetadataRedaction(MetadataFilters.All)
   }; 
   RedactorChangeLog result = redactor.Apply(redactionList);
   // false, if at least one redaction failed
   if (result.Status != RedactionStatus.Failed)
   {
      redactor.Save();
   };
}

More resources

Advanced usage topics

To learn more about document redaction features, please refer to the advanced usage section.

GitHub examples

You may easily run the code above and see the feature in action in our GitHub examples:

Free online document redaction App

Along with full featured .NET library we provide simple, but powerful free Apps.

You are welcome to perform redactions for various document formats like PDF, DOC, DOCX, PPT, PPTX, XLS, XLSX, Emails and more with our free online Free Online Document Redaction App.