Remaining Backward Compatible

We are constantly working to improve webOS TV, and as a result, various specifications and features have been newly added or changed to the webOS TV platform. For example, the web engine used in the webOS TV platform had been changed from WebKit to Blink at the release of webOS TV v3.0. Due to this kind of changes, your app made for previous webOS TVs might not work on the latest version of webOS TV. It is time for you to consider backward compatibility.
The following guide describes the issues arising from version difference and how to make the code work across all versions of webOS TV.

addEventListener() function MUST be used for registering event handler on webOS TV 2.0 and earlier.
Use both unprefixed and prefixed flag for CSS modules such as Transforms, Transition, and Animation.
When changing the source of the video element, you need to initiate the video playback on webOS TV 3.0 and later.