When you embed a video via iframe from Vimeo, Kaltura, or MS Stream, the embed code requires a few html attributes that make it possible to view the videos in full-screen mode. However, those attributes are stripped from the iframe code during the cooking process. This plugin whitelists the attributes required to allow full-screen buttons and capabilities.
I should also note that in order for this to work, you’ll need to add the source domain for these iframes to the allowed iframes site setting. Otherwise, the iframe will be ignored entirely.
Sidenote: This is work that was sponsored by a client who wanted to remain anonymous, but wanted to share their project with the community.
