Detect Document Height Change

Question

I\'m trying to detect when my document height changes. Once it does, I need to run a few functions to help organize my page layout.

I\'m not looking fo

Answer 1

I'm using @vsync's solution, like this. I'm using it for automatic scroll on a page like twitter.

const scrollInterval = (timeInterval, retry, cb) => {
    let tmpHeight = 0;
    const myInterval = setInterval(() => {
        console.log('interval');
        if (retry++ > 3) {
            clearInterval(this);
        }
        const change = document.body.clientHeight - tmpHeight;
        tmpHeight = document.body.clientHeight;
        if (change > 0) {
            cb(change, (retry * timeInterval));
            scrollBy(0, 10000);
        }
        retry = 0;
    }, timeInterval);
    return myInterval;
};

const onBodyChange = (change, timeout) => {
    console.log(`document.body.clientHeight, changed: ${change}, after: ${timeout}`);
}

const createdInterval = scrollInterval(500, 3, onBodyChange);

// stop the scroller on some event
setTimeout(() => {
    clearInterval(createdInterval);
}, 10000);

You can also add a minimum change, and a lot of other things... But this is working for me

Answer 2

As mentioned by vsync there is no event but you can use a timer or attach the handler somewhere else:

// get the height
var refreshDocHeight = function(){
    var h = $(document).height();
    $('#result').html("Document height: " + h);
};

// update the height every 200ms
window.setInterval(refreshDocHeight, 200);

// or attach the handler to all events which are able to change 
// the document height, for example
$('div').keyup(refreshDocHeight);

Find the jsfiddle here.