Architectural issue: CMS page revision history

Question

For my personal website, I am currently developing a CMS module. One of the features of the CMS module is page revision history. The website data access layer is being developed in Entity Framework Code First.

The problem I have is: How will I assign an 'active' revision to a page?

I see currently two options:

• The Page class / table will have an CurrentRevision property/field which will point to the active page revision.

  • The pro is obviously being able to look it up easily and being able to change it easily.
  • The con is that the field will have to be nullable, otherwise there will be a cyclic dependency between the tables, not sure if EF will accept it. Also, saving the changes in EF will require two steps.

• The page revision class / table will have an IsOnline property.

  • The pro is, saving will only require one step.
  • The cons here is that it will obviously not prevent having multiple active revisions, it won't prevent having none active revisions either. Also, lookup in LINQ queries can't be simplied because we will always have to use First (or something like that).

What is the best way to implement this?

Answer 1

I didn't try it but I would try use the first approach. The con is not so big as it looks like because two database modifications command are not such a big problem (page publication is not operation you would do 100x per second) and in most scenarios you will need it anyway if your CMS will provide page editor because you will first save draft multiple times (no current online version) and only after that you will publish the page (you will have current online version).

You will still need to use the second approach if you would like to provide access to the last revision because the last revision doesn't have to be the published one.