GPT interstitial support - SafeFrames

[ourcraig]

Type of issue

Bug/Feature Request

Description

The current version of the Prebid Universal Creative does not support GPT out-of-page interstitials in a SafeFrame environment.

The ucTagData.pubUrl differs from the SafeFrame origin, leading to a postMessage error e.g.

Failed to execute 'postMessage' on 'DOMWindow': The target origin provided ('https://ourcraig.github.io') does not match the recipient window's origin ('https://8d4de8f36eb4e4b3193097ff2b247e5e.safeframe.googlesyndication.com').

Changing the pubUrl to "*" does not resolve the issue due to the GPT interstitial creating an iframe within the SafeFrame that the Prebid Universal Creative postMessage does not break out of.

Would it be possible to get support for GPT out-of-page interstitials in a SafeFrame environment?

Test page

pbjs-instl-tests

• standard shows PUC rendering fine in a non-SafeFrame environment
• standard-sf shows postMessage error when trying to render inside of a SafeFrame environment

Other information

• GPT interstitial has a frequency cap of one view per user per hour -- to refresh it use localStorage.clear() on the test page
• GPT docs for out-of-page interstitial here

[patmmccann]

This is a dupe of #5917