Event System to disable transaction save

Question

We have a requirement where we need to disable creating transactions in some Publications. We cannot remove these publications from Publication Target, because we need them, but we would like to do it via the Event System for example on transaction save args.

I have tried in EventPhase.Initiated, but nothing seems to work.

Has anyone had similar requirement and how did they achieve it?

UPDATE:

OK, so here is my thing, to make it plastic.

We have Publications:

• level 1
• level 2
• level 3
• level 4

I want to be able to publish from each of these levels, but, if I send item to publish from level 1 in all child Publications (2, 3, 4), I want to have only transactions from level 1 and 4. I also don't want to remove level 2 and 3 from Publication Target, because then I will not be able to publish from that level in all children (level 4), which is a must.

Answer 1

I'm mainly responding to your comment on @Harald's answer, and the removal of these empty Publish Transactions.

What I find interesting in your question is that you seem to want to find a way to remove certain items from your publish action, but I didn't actually understand if you have a clear algorithm for that. Because without that I would say it is impossible to automate.

But on the actual task of the removal of empty Publish Transactions, I can suggest the following example code:

1. https://appstore.sdl.com/web-content-management/app/child-publications-only-resolver/621/
2. https://appstore.sdl.com/web-content-management/app/empty-publish-transactions-event-handler/622/

To answer @Atila's question in the comments, no it is not possible to cancel an ongoing action using Tridion Event System besides throwing an exception. You can only stop it by throwing an exception, that is the mechanism that is designed to stop actions from the event system.

Answer 2

If I understand well, you want to remove items published from certain publications from the publish transaction. I'm not sure if it would work (i've never tried it myself) but usually, you can build a custom resolver to deal with things like this.

In a custom resolver, you should be able to add or remove items from a publish transaction.

See some sample code here : http://www.tridiondeveloper.com/a-custom-resolver-in-practice

you could try something like this

foreach (ResolvedItem resolvedItem in originalResolveItemList)
{
     if (resolvedItem publication ID is in list of unpublishable publication ids)
     {
           resolvedItems.Remove(resolvedItem); // remove from items that will be published..
     }
}