Tumblr is a microblogging and social networking website.
Marfeel uses the embed feature to display Tumblr posts.
To implement the Tumblr extension, Marfeel copies the iframe on the frontend along with its source and the data-href attribute.
On the backend, Marfeel inspects if the source of the iframe identified in an article is in the allowed sources. If it is, Marfeel displays the iframe on the frontend.
The iframe's source is only loaded when it's inside the viewport.
Tumblr is disabled by default for the Marfeel solution, however it can be promptly activated by customer request.