There are 4 different properties to look into to get the height of the content in an iFrame.
document.documentElement.scrollHeight
document.documentElement.offsetHeight
document.body.scrollHeight
document.body.offsetHeight
Sadly they can all give different answers and these are inconsistent between browsers. If you set the body margin to 0 then the document.body.offsetHeight gives the best answer. To get the correct value try this function; which is taken from the iframe-resizer library that also looks after keeping the iFrame the correct size when the content changes,or the browser is resized.
function getIFrameHeight(){
function getComputedBodyStyle(prop) {
function getPixelValue(value) {
var PIXEL = /^\d+(px)?$/i;
if (PIXEL.test(value)) {
return parseInt(value,base);
}
var
style = el.style.left,
runtimeStyle = el.runtimeStyle.left;
el.runtimeStyle.left = el.currentStyle.left;
el.style.left = value || 0;
value = el.style.pixelLeft;
el.style.left = style;
el.runtimeStyle.left = runtimeStyle;
return value;
}
var
el = document.body,
retVal = 0;
if (document.defaultView && document.defaultView.getComputedStyle) {
retVal = document.defaultView.getComputedStyle(el, null)[prop];
} else {//IE8 & below
retVal = getPixelValue(el.currentStyle[prop]);
}
return parseInt(retVal,10);
}
return document.body.offsetHeight +
getComputedBodyStyle('marginTop') +
getComputedBodyStyle('marginBottom');
}
