SharePoint rename file on overwrite

Question

I have a simple requirement, yet it seems very complex to implement. When users upload a file to the document library, I want to check if it exists. If it exists I need to rename the file by appending the date (and time) to the end of the file - so that it is unique.

The obvious answer is to use event receivers. When you overwrite a document, It is the update events that fire not the adding events.

My problem is that I cannot tell whether the file is being overwritten or if there it is a property update. Am I missing something obvious?

Answer 1

You could use versioning on the library. That way, when a file of the same name is uploaded, it will be saved as a new version and the previous version(s) can still be accessed. No code, no event receivers, just out of the box.

Answer 2

The file will be overwritten in the same item. In the other hand I just wondering why you should overwrite the file by a Event Receiver instead to enable the Versioning of the file.