Approve modification on entity before publish - postgresql

Question

I am trying to create a system that requires an admin to approve a modification to an entity before being published. This system is a REST API with authentication/authorization already working, so that part is not important. Let's assume we have a model depicting an article, with a title and a body. A normal user is allowed to modify all the fields, but before the article is published, it must be approved by an admin. But while the article is in ``approval mode'', the old version of the article must be accessible by the REST API so to at least have a version that works (and the API does not return a 404).
The requirements are:
I am using Spring Data and PostgreSQL so the one that gives me less headaches while integrating it is the one I am going with
The less tinkering with weird checks, the better
If possible, it should be modifiable to be used with other entities
If possible, I would like to keep the old versions and who modified them. Non essential but would be nice
I have two different ideas, but I am not sure which one is the best one:
Create an abstract parent class, and then extend it with an approved and a non-approved version. Then, when the modification is approved the entity is transformed into an approved one and the API will return the new version:
public abstract class Article {}
public class ApprovedArticle extends Article {}
public class ModifiedArticle extends Article {}
Create a separate table where the modified entities are stored, and restrict the view to be admin only. In this case I would isolate the two types and make it easier when fetching info. But I am losing the ``history'' this way and I need to fetch from two different locations.
Simple boolean flag: this is my last resort, and I would love to avoid it!
Is there a better way or should I use one of the outlined examples?
Thanks!

Answer 1

Look into spring Auditing.
https://www.baeldung.com/database-auditing-jpa
So there is an idea:
for each table you have a history table, each history table has REVTYPE( “0” for adding, “1” for updating, “2” for removing an entity) and REV(change number) columns.
Besides these, you need an extra table named REVINFO will be generated by default, to have user details you need to extend default DefaultRevisionEntity class.
#Entity
#RevisionEntity(YOURRevisionListener.class)
#Table(name = "your_audit_info")
#AttributeOverrides(
{#AttributeOverride(name = "timestamp", column = #Column(name = "REVTSTMP")),
#AttributeOverride(name = "id", column = #Column(name = "REV"))})
public class AuditInfo extends DefaultRevisionEntity
{
private static final long serialVersionUID = 8458400378132903089L;
#Column(name = "UpdateUser", nullable = false)
private String userName;
public String getUserName()
{
return userName;
}
public void setUserName(
final String userName)
{
this.userName = userName;
}
}
with audit set up, you get user details if the change approved by admin then compare revisions number when the operation started and operation approved to avoid overwriting by others.
#PrePersist
public void onPrePersist() {
audit("INSERT");
}
#PreUpdate
public void onPreUpdate() {
audit("UPDATE");
}
#PreRemove
public void onPreRemove() {
audit("DELETE");
}
I know it is a very high-level approach, but it can work in your case