Inject VAST impressions even if no impression tag

[bretg]

The most recent Prebid Server Events and Analytics PRD defines the algorithm for injecting VAST impressions as:

Inline VAST - search for . Add PBS Impression tag(s) after existing tag. If no tag is found, it's an unexpected error and this VAST is suspicious. Don't add any PBS Impression tags.

Perhaps not surprisingly, a bidder has been found that doesn't conform to expectations. And it's none other my own company. :-). Though in my defense, it's a recent addition to the family... SpotX creates VAST wrappers that rely on VPAID that do not create tags.

So the updated proposal is:

Inline VAST - search for <Impression>. Add PBS Impression tag(s) after existing tag. If no <impression> tag is found, look for the </Inline> ending tag. Insert the <Impression> tag just before that. If there is neither <impression> nor </Inline>, it's an unexpected error and this VAST is suspicious. Don't add any PBS Impression tags.

Discussing with some internal VAST experts, we believe this should work, but would like to give the community a chance to weigh in.

[SyntaxNode]

@laurb9 Implemented this feature for PBS-Go. Do you have an opinion on this Laurentiu?

[mansinahar]

I checked about this with Xandr's video team and got the following response:

As long as the link in the node is valid AND the receiving end knows what to do with it (meaning collecting and reporting the impression), the node can be added anywhere in an node as long as it is a child node of . This means you cannot stick inside of or any other child node of . must be a direct child of

From the above proposal, I believe we're good here.

It is also important to note that you can also add an node to a node, as a direct child. The node is not limited to the node. So any VAST wrapper can also include one or more nodes. Both and nodes can include multiple nodes. All nodes present in the VAST xml must be reported by the player.

About this, perhaps we need to include looking for the impression tag in the <Wrapper> tag as well?

[vpitts]

Hi all - I am part of Xandr's video team who provided the response that Mansi cited above. I wanted to add an additional comment to the above response.

Above, it was mentioned that "SpotX creates VAST wrappers that rely on VPAID that do not create tags". This needn't be a factor that needs to be considered when adding an Impression node as a child to either the Inline node or to the Wrapper node. Per spec, any VPAID creative is required to report an AdImpression event to the player where the VPAID creative is being rendered. This allows the player to report any and all Impression value(s) that have been specified in VAST xml that is external to the VPAID creative.

[bretg]

perhaps we need to include looking for the impression tag in the Wrapper tag as well?

It's doing a full scan now. Anywhere it finds <Impression>, it will append it's own imp afterwards. So I think we're covered here.

VPAID creative is required to report an AdImpression event to the player

I'm not familiar with VPAID, but would have to assume SpotX is doing the right thing here. Would we see an AdImpression event in the VAST? I do see this:

<AdParameters>
       <![CDATA[{...
           "tracking":{"beacon":[{"type":"impression","beacon_url": "..."
...

[vpitts]

@bretg - AdImpression is the name of one of the events that a VPAID creatives sends to the player. A player that knows how to load and render a VPAID creative knows to look for that event. You will not see AdImpression in the VAST. It is simply an event that triggers the player to report any value that has been specified in one or more Impression nodes in the VAST.

[bretg]

Released with PBS-Java 1.71.

[stale]

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