Scott,
My understanding is that one should always attempt to obtain a document lock before changing any keyword values on a document. I believe this is in order to be sure that there aren't any other user locks on that document that moment, and in order to lock the document during your keyword changes -- I'm not aware of any locks being put on the document automatically. Although I guess a process running a timer which has Rules or Actions which change keyword values would be locking the document also.
Anyway... here's a code sample showing an example of changing keyword values (C#). This example is actually removing keywords, but the idea is basically the same whether you're adding, updating, or removing keyword values. 'args' is a Hyland.Unity.WorkflowEventArgs object.
1. obtain DocumentLock and check that its Status is not 'AlreadyLocked'
using (DocumentLock objDocLock = args.Document.LockDocument())
{
if (objDocLock.Status == DocumentLockStatus.AlreadyLocked)
{
// do not attempt to update/remove keywords, otherwise, continue
}
2. create the KeywordModifier object
KeywordModifier objKeyModifier = args.Document.CreateKeywordModifier();
3. work on your keywords (update/remove/etc)
foreach (KeywordRecord objKeyRecord in args.Document.KeywordRecords.FindAll(objKWRecType))
{
objKeyword = objKeyRecord.Keywords.Find(objKWTypeAppTime);// there is only one
{
if (objKeyword.DateTimeValue.CompareTo(this.ApprovalTime) >= 0)
{
objKeyModifier.RemoveKeywordRecord(objKeyRecord);
}
}
}
4. apply changes via the KeywordModifier (otherwise they are lost)
objKeyModifier.ApplyChanges();
5. release DocumentLock (in this example the release occurs at closing brace of 'using' block)
}
I hope that's helpful,
Rob
