How to determine in a Custom Resolver if I am publishing or unpublishing? Tridion 2009 SP1

Question

I'm trying to capture when a component is unpublished. I try some approaches but I don't have the result that I want. My attempts are:

1. In Event System. But this not works because there are a known bug in Windows about MSXML and COM+.

2. I try to build my own IResolver but there I cannot determine if it's a publishing or unpublishing action.

3. I try to build my own ITransportPackageHandler. There, I have a function called HandleResolvedItemForUnPublishing but I don't have any information about PublicationTarget and I don't know if it's unpublished from staging or live.

Can someone help me? I think that I can solve the problem if:

1. At the IResolver I can determine if the component is unpublishing.
2. At the ITransportPackageHandler I can access to the PublicationTarget info
3. If I can pass info from IResolver to the ITransportPackageHandler in a context variable or something similar.

thank you very much.

Gustavo.

Answer 1

You should be able to look at the ResolvePurpose of the ResolveInstruction that you get as one of the parameters in the custom resolver. Something along these lines:

public void Resolve(IdentifiableObject item, ResolveInstruction instruction, PublishContext context, ISet<ResolvedItem> resolvedItems)
{
    if (instruction.Purpose == ResolvePurpose.Publish || instruction.Purpose == ResolvePurpose.RePublish)
    { 
        // We are publishing
    }
    else if(instruction.Purpose == ResolvePurpose.UnPublish)
    {
        // We are unpublishing
    }
    // Don't know if this one exists in 2009, it exists in 2011 SP1
    else if(instruction.Purpose == ResolvePurpose.UnknownByClient)
    {
        // The server is doing something that I don't understand (yet?)
    }
}

EDIT

I refused to not find a way to make this work...

Indeed, in Tridion 2009 you don't have a Purpose on the resolve instruction. You do have an Action in the Publish Transaction, but this one is not exposed directly in the resolver. Here's how I found out if I'm publishing or unpublishing - your call if think it's overkill, but performance on my non-production VM was pretty good.

1. Find the current item we're resolving for
2. Load the list of PublishTransaction with a state of "In Progress"
3. Find the transaction for the current item
4. Determine the action by looking at the Action attribute

Filter filter = new Filter();
filter.Conditions["InfoType"] = 2; // Get transactions in Progress
foreach (XmlNode node in item.Session.GetList(typeof(PublishTransaction), filter))
{
    if(node.Attributes["ItemID"].Value.Equals(item.Id.ToString()))
    {
        // we have a winner
        string action;
        if (node.Attributes["Action"].Value.Equals("0"))
            action = "Publish";
        if (node.Attributes["Action"].Value.Equals("1"))
            action = "Unpublish";
    }
}