make iframe height dynamic based on content inside

Question

I am loading an aspx web page in an iframe. The content in the Iframe can be of more height than the iframe's height. The iframe should not have scroll bars.

I have a wrapper div tag inside the iframe which basically is all the content. I wrote some jQuery to make the resize happen :

$("#TB_window", window.parent.document).height($("body").height() + 50);

where TB_window is the div in which the Iframe is contained.

body - the body tag of the aspx in the iframe.

This script is attached to the iframe content. I am getting the TB_window element from the parent page. While this works fine on Chrome, but the TB_window collapses in Firefox. I am really confused/lost on why that happens.

Answer 1

Just in case this helps anyone. I was pulling my hair out trying to get this to work, then I noticed that the iframe had a class entry with height:100%. When I removed this, everything worked as expected. So, please check for any css conflicts.

Answer 2

A slightly improved answer to BlueFish...

function resizeIframe(iframe) {
    var padding = 50;
    if (iframe.contentWindow.document.body.scrollHeight < (window.innerHeight - padding))
        iframe.height = iframe.contentWindow.document.body.scrollHeight + "px";
    else
        iframe.height = (window.innerHeight - padding) + "px";
}

This takes in consideration the height of the windows screen(browser, phone) which is good for responsive design and iframes that have huge height. Padding represents the padding you want above and below the iframe in the case it goes trough whole screen.

Answer 3

To add to the chunk of window that seems to cut off at the bottom, especially when you don't have scrolling I used:

function resizeIframe(iframe) {
    var addHeight = 20; //or whatever size is being cut off
    iframe.height = iframe.contentWindow.document.body.scrollHeight + addHeight + "px";
  }

Answer 4

Rather than using javscript/jquery the easiest way I found is:

<iframe style="min-height:98vh" src="http://yourdomain.com" width="100%"></iframe>

Here 1vh = 1% of Browser window height. So the theoretical value of height to be set is 100vh but practically 98vh did the magic.

Answer 5

The simple solution is to measure the width and height of the content area, and then use those measurements to calculate the bottom padding percentage.

In this case, the measurements are 1680 x 720 px, so the padding on the bottom is 720 / 1680 = 0.43 * 100, which comes out to 43%.

.canvas-container {    
    position: relative;
    padding-bottom: 43%; // (720 ÷ 1680 = 0.4286 = 43%)
    height: 0;
    overflow: hidden;   
}

.canvas-container iframe {    
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;   
}

Answer 6

There are four different properties you can look at 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 inconsistant 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');
}