getComputedStyle. It was exactly what I was looking for.
It takes a second param for the property, but if you omit, it reuturns all.
It returns an "Array like" object of type
CSSStyleDeclaration that can be converted to an array and iterated on. using the
getPropertyValue method the value of the keys can be retrieved.
The interesting part is this bit from MDN.
The returned style is a live CSSStyleDeclaration object, which updates itself automatically when the element's style is changed.
All the way back to IE 9
IE ✘ 5.5+ ✔ 9+ Edge ✔ Firefox ✘ 2+ ◒ 3+¹ ✔ 4+ Chrome ◒ 4+² ✔ 11+ Safari ◒ 3.1+² ✔ 5+ Opera ◒ 9+² ✔ 10.6+
➜ Read more on MDN