Document Toolkit History Tracking

LEADTOOLS now supports retrieving the history of a document to determine if the document needs to be updated in other storage mediums.

Types of changes that are tracked include:

Document Creation
Document Decryption
Pages added/removed/re-ordered
Pages rotated
Pages marked as disabled/deleted
Page SVG or Image modification
Page Text or Links modification
Page Annotations modification

History tracking of a LEADDocument object is performed using the History property, which is a DocumentHistory type. The DocumentHistory class contains the following members:

Member	Description
AutoUpdate	Enables history tracking. The default value is false. Modifications to the document are not tracked until the value is set to true.
GetItems	Retrieves the document's modification history.
SetItems	Manually updates the document's modification history.
Clear	Resets the document's modification history.

GetItems returns a list of DocumentHistoryItems. Each item describes the type of change and page numbers affected for logging purposes.

Each DocumentHistoryItem item contains the following members:

Member	Description
UserId	The ID of the user at the time of the modification. This is set to the value of LEADDocument.UserId.
Timestamp	The timestamp of the modification. This value is in UTC and created in the "yyyy-MM-ddTHH:mm:ss" format.
Comment	User-defined comment.
ModifyType	The type of change (modification).
PageNumber	The page number associated with this change.

When the value of LEADDocument.History.AutoUpdate is true, the document will record each change described below by automatically adding a new entry to the items in DocumentHistory. If the document uses caching, then the history is stored into and retrieved from the cache.

The following table describes when history items are added when the value of AutoUpdate is true:

Operation	Description
DocumentFactory.Create	DocumentHistoryModifyType.Created entry is added.
LEADDocument.Decrypt	DocumentHistoryModifyType.Decrypted entry is added.
LEADDocument.Pages	DocumentHistoryModifyType.Pages entries are added when pages are added, removed or re-arranged in the document.
DocumentPage.Rotate, DocumentPage.Flip, DocumentPage.Reverse	documenthistorymodifytype.pageviewperspective entry is added.
DocumentPage.IsDeleted	DocumentHistoryModifyType.PageMarkDeleted entry is added.
DocumentAnnotations.SetAnnotations	and DocumentPage.SetAnnotations DocumentHistoryModifyType.PageAnnotations entry is added.
DocumentPage.SetLinks	DocumentHistoryModifyType.PageLinks entry is added.
DocumentPage.SetImage	DocumentHistoryModifyType.PageImage entry is added.
DocumentPage.SetSvg	DocumentHistoryModifyType.PageSvg entry is added.
DocumentPage.SetSvgBackImage	DocumentHistoryModifyType.PageSvgBackImage entry is added.

When DocumentAnnotations.SetAnnotations or DocumentPage.SetAnnotations is called, a single entry with DocumentHistoryModifyType.PageAnnotations is added. However, the user can retrieve more information about the type of changes to the annotations by calling DocumentAnnotations.GetHistory.

Refer to DocumentHistory for an example.

Document Toolkit History Tracking

See Also