Support DFP Premium Same Ad Unit Multiple Slots

[prebid]

As a publisher, I would like Prebid.js to support the case where I have one ad unit reused across multiple slots. For example:

googletag.defineSlot('/1234/Leaderboard', [728, 90], 'div-gpt-ad-5678-2').setTargeting('Position',['bottom']).addService(googletag.pubads());

googletag.defineSlot('/1234/Leaderboard', [[970, 90],[970, 250],[728, 90]], 'div-gpt-ad-5678-3').setTargeting('Position',['top']).addService(googletag.pubads());

(In this case, the same ad unit is served into multiple ad slots)

googletag.defineSlot('/1234/Leaderboard', [728, 90], 'div-gpt-ad-5678-2').setTargeting('Position',['bottom']).addService(googletag.pubads());

googletag.defineSlot('/1234/MobileMediumRectangle', [[300, 250],[320,100]], 'div-gpt-ad-5678-2').setTargeting('Position',['bottom']).addService(googletag.pubads());

(In this case, multiple ad units serve into the same ad slot)

We need to come up with an example to support the above cases.

[prebid]

Proposed solution:

Instead of using ad unit path ('/1234/Leaderboard'), we should use the slot element ID ('div-gpt-ad-5678-2') as the code for prebid ad units.

For example:

var adUnits = [{
    code: 'div-gpt-ad-5678-2',
    sizes: [...]
    bids: [...]
}]

If 2 prebid ad units for some reason share the same code (DFP slot element ID) in this case, we'll combine the 2 ad units' result bids together.

GPT has the function getSlotElementId() that can be used to get an ad slot's element ID.

[RobertLippens]

👍 this feature request, this is currently a blocking item for us.

[RobertLippens]

Update: I have been fiddling around with the source code a bit and have been able to get two ads of different sizes using the same slot with the suggested method above.

var rightSlot = googletag.defineSlot('12345/slot/name', [[300, 250]], 'div1').addService(googletag.pubads());
var topSlot = googletag.defineSlot('12345/slot/name', [[728,90]], 'div2').addService(googletag.pubads());

with adUnits defined:

{
        code: 'div1',
        sizes: [[300, 250]],
        bids: [
          {
              bidder: 'yieldbot',
              params: {
                psn: 'TOADD',
                slot: 'TOADD'
              }
            }]
    }

and

{
        code: 'div2',
        sizes: [[728, 90]],
        bids: [
          {
              bidder: 'yieldbot',
              params: {
                psn: 'TOADD',
                slot: 'TOADD'
              }
            }]
    }

The necessary code change appears to be in prebid.js at setTargetingForAdUnitsGPTAsync (on line 442). The for-loop contents can be replaced with:

            var adUnitCode = slots[i].getSlotElementId();
            if (adUnitCode) {
                placementBids = getBidResponsesByAdUnit(adUnitCode);
                setGPTAsyncTargeting(slots[i].getAdUnitPath(), slots[i], placementBids);
            }

where the adUnitCode is now based on the SlotElementId as suggested, though the GPTAsyncTargeting is still based on the adUnitPath as it was previously.

I have added this to a forked PR #77

[mkendall07]

Hi @RobertLippens

Thanks for the contributing. I will also update the code to reflect a fallback to getAdUnitPath() if getSlotElementId() is empty