nl_tokens: Clone an element outside the screen to safely get its height then destroy it .
pl_tokens: function getElementHeight ( element ) { var clone = element . cloneNode ( true ) clone . style . cssText = 'visibility: hidden; display: block; margin: -999px 0' var height = ( <mask> . parentNode . appendChild ( clone ) ) . clientHeight element . parentNode . removeChild ( clone ) return height }