How to get height of entire document with JavaScript?

Question

Some documents I can\'t get the height of the document (to position something absolutely at the very bottom). Additionally, a padding-bottom on seems to do nothing on these

Answer 1

For anyone having trouble scrolling a page on demand, using feature detection, I've come up with this hack to detect which feature to use in an animated scroll.

The issue was both document.body.scrollTop and document.documentElement always returned true in all browsers.

However you can only actually scroll a document with either one or the other. d.body.scrollTop for Safari and document.documentElement for all others according to w3schools (see examples)

element.scrollTop works in all browsers, not so for document level.

    // get and test orig scroll pos in Saf and similar 
    var ORG = d.body.scrollTop; 

    // increment by 1 pixel
    d.body.scrollTop += 1;

    // get new scroll pos in Saf and similar 
    var NEW = d.body.scrollTop;

    if(ORG == NEW){
        // no change, try scroll up instead
        ORG = d.body.scrollTop;
        d.body.scrollTop -= 1;
        NEW = d.body.scrollTop;

        if(ORG == NEW){
            // still no change, use document.documentElement
            cont = dd;
        } else {
            // we measured movement, use document.body
            cont = d.body;
        }
    } else {
        // we measured movement, use document.body
        cont = d.body;
    }