Absolute / fixed position DOM elements obscuring viewability?

[griffinmichl]

This library is incredibly helpful!

I notice that it does not take into account other DOM elements (ex. absolute / fixed positioned ones) obscuring the element being observed. Is it necessary to take this case into account in order to meet IAB guidelines for viewability, or is the DOM element just being in the view port enough to count as in view?

Thanks!

[jdreetz]

We had the ability to check for DOM obscuring in the previous version of OpenVV - https://github.com/InteractiveAdvertisingBureau/openvv/blob/master/src/org/openvv/js/OVVAsset.js#L1125

I'm assuming it only worked for same domain iFrames though, as you could only check for overlapping elements in the same document. We might want to consider adding it as an available MeasurementTechnique. Then users could create composite MeasurementTechniques that determine whether an element is "in view" based on IntersectionObserver AND Dom Obscuring if they have that requirement.

With respect to IAB's requirements for viewability, I wasn't aware DOM obscuring was one of them. @iabshailley might have more information about that.

[griffinmichl]

With respect to IAB's requirements for viewability, I wasn't aware DOM obscuring was one of them.

I actually have no idea if that's the case or not. I was mainly asking here. It seems very difficult to performantly check for DOM obscuring.

[goosemanjack]

SafeFrame has code that does just this by walking up the DOM tree for overlapping elements, then querying for absolute and relative positioned elements. I may be mis-remembering some of the details on this, but it was somewhat expensive and required throttling. SafeFrame also requires host-side library in addition to the ad-side library, so it's more complicated to set up.