Is there a rails plugin to do effective dating

Question

Something like act_as_taggable or act_as_versioned but for SAP style effective dating?

Sorry for the lack of details. Here is some more:

The plugin would add a start_date and end_date to a model.

• Basic operation should always be on entity valid for today or a parameter date
• Update should make a copy of the effective entity with a start date of now and update the existing entity to set the end date now
• Delete should just set the end date to now on the existing entity
• Probably many more, but those cover the basic idea.

This is the way SAP handles versioning of entities. Does anyone knows of a plugin that does something similar?

Answer 1

I recommend you add some more details or clarification before the wrath of SO descends upon you.

Answer 2

This is a tough problem. This means that every change you make to your tables take an "effective date" parameter. For example: Person X will be moving to a new address effective a month from now. So when you query the table today, you see the current address. If you were to query with an effective date of a month from now, you would see the new address.

And that goes for everything you enter in the app. Everything has a concept of when it became a fact. And you can see the values at any point in time, exactly as they were.

We are in the midst of finishing a rails project addressing this issue in an HR app. we will post something once this is completed.