Why does DFP/GAM setTargeting option not work with prebid? - google-dfp

Question

When we use the DFP option used to target ads with a Key/Value pair we noticed it does not work when Prebid is also running. It appears that Prebid is overriding the setTargeting option. It would seem to be a common issue, but I cannot find any information about it.
If I disable prebid, the setTargeting works fine.
I've also tried placing the setTargeting inside the pbjs.que.push function, just after pbjs.setTargetingForGPTAsync(); but that did not help.
I've paired down the code to include just the basic setup to show how we have things configured.
<script src='https://www.googletagservices.com/tag/js/gpt.js'></script>
<script type="text/javascript" src="https://ads.bninews.com/corporate/prebid/latest/prebid.js"></script>
<script type="text/javascript" src="https://ads.bninews.com/corporate/prebid/latest/prebid_config.js?20180913"></script>
<script>
var googletag = googletag || {};
googletag.cmd = googletag.cmd || [];
</script>
<script>
googletag.cmd.push(function() {
googletag.defineSlot('/XXX/slot-300x250-1', [[300, 250]], 'div-gpt-ad-bigblock-1').addService(googletag.pubads());
googletag.pubads().setTargeting("pageurl", "/home/");
googletag.pubads().enableSingleRequest();
googletag.pubads().disableInitialLoad();
googletag.enableServices();
});
</script>
<!-- Prebid Boilerplate Section START -->
<script>
pbjs.que.push(function() {
pbjs.addAdUnits(adUnits);
pbjs.requestBids({
bidsBackHandler: initAdserver,
timeout: PREBID_TIMEOUT
});
});
function initAdserver() {
if (pbjs.initAdserverSet) return;
pbjs.initAdserverSet = true;
googletag.cmd.push(function() {
pbjs.que.push(function() {
pbjs.setTargetingForGPTAsync();
googletag.pubads().refresh();
});
});
}
// in case PBJS doesn't load
setTimeout(function() {
initAdserver();
}, FAILSAFE_TIMEOUT);
</script>
<!-- Prebid Boilerplate Section END -->

Answer 1

It's definitely the sequence of events that is wrong. I don't even think pbjs.setTargetingForGPTAsync() is needed at all, but you do need to wait for prebid to return with the bids before googletag.pubads().setTargeting("pageurl", "/home/");
You can solve this with a Promise that would be wrapped around prebid, and wait for the promise to resolve inside so something like:
var prebidPromiseResponse = new Promise( function(resolve){
pbjs.que.push(function() {
pbjs.addAdUnits(adUnits);
pbjs.requestBids({
bidsBackHandler: function(bids){
if (pbjs.initAdserverSet) return;
pbjs.initAdserverSet = true;
googletag.cmd.push(function() {
pbjs.que.push(function() {
resolve(bids);
});
});
},
timeout: PREBID_TIMEOUT
});
});
})
And then google tag
googletag.cmd.push(function() {
googletag.defineSlot('/XXX/slot-300x250-1', [[300, 250]], 'div-gpt-ad-bigblock-1').addService(googletag.pubads());
prebidPromiseResponse.then(function(bids){
googletag.pubads().setTargeting("pageurl", "/home/");
googletag.pubads().enableSingleRequest();
googletag.pubads().disableInitialLoad();
googletag.enableServices();
});
});