contenteditable, set caret at the end of the text (cross-browser)

output in Chrome:

<div id="content" contenteditable="true" style="border:1px solid #000;width:500px;height:40px;">
    hey
    <div>what's up?</div>
<div>
<button id="insert_caret"></button>

I believe in FF it would look something like this:

hey
<br />
what's up?

and in IE:

hey
<p>what's up?</p>

unfortunately, there is no nice way of making it so that every browser inserts a <br /> instead of a div- or p-tag, or at least I couldn't find anything online.

---

ANYWAY, what I am trying to do now is, when I hit the button, I want the caret to be set at the end of the text, so it should look something like this:

hey
what's up?|

any way to do this so it works in all browser?

example:

$(document).ready(function()
{
    $('#insert_caret').click(function()
    {
        var ele = $('#content');
        var length = ele.html().length;

        ele.focus();

        //set caret -> end pos
     }
 }

The following function will do it in all major browsers:

function placeCaretAtEnd(el) {
    el.focus();
    if (typeof window.getSelection != "undefined"
            && typeof document.createRange != "undefined") {
        var range = document.createRange();
        range.selectNodeContents(el);
        range.collapse(false);
        var sel = window.getSelection();
        sel.removeAllRanges();
        sel.addRange(range);
    } else if (typeof document.body.createTextRange != "undefined") {
        var textRange = document.body.createTextRange();
        textRange.moveToElementText(el);
        textRange.collapse(false);
        textRange.select();
    }
}

placeCaretAtEnd( document.querySelector('p') );

p{ padding:.5em; border:1px solid black; }

<p contentEditable>foo bar </p>

Placing the caret at the start is almost identical: it just requires changing the Boolean passed into the calls to collapse(). Here's an example that creates functions for placing the caret at the start and at the end:

function createCaretPlacer(atStart) {
    return function(el) {
        el.focus();
        if (typeof window.getSelection != "undefined"
                && typeof document.createRange != "undefined") {
            var range = document.createRange();
            range.selectNodeContents(el);
            range.collapse(atStart);
            var sel = window.getSelection();
            sel.removeAllRanges();
            sel.addRange(range);
        } else if (typeof document.body.createTextRange != "undefined") {
            var textRange = document.body.createTextRange();
            textRange.moveToElementText(el);
            textRange.collapse(atStart);
            textRange.select();
        }
    };
}

var placeCaretAtStart = createCaretPlacer(true);
var placeCaretAtEnd = createCaretPlacer(false);

Unfortunately Tim's excellent answer worked for me only for placing at the end, for placing at the start I had to modify it slightly.

function setCaret(target, isStart) {
  const range = document.createRange();
  const sel = window.getSelection();
  if (isStart){
    const newText = document.createTextNode('');
    target.appendChild(newText);
    range.setStart(target.childNodes[0], 0);
  }
  else {
    range.selectNodeContents(target);
  }
  range.collapse(isStart);
  sel.removeAllRanges();
  sel.addRange(range);
  target.focus();
  target.select();
}

Not sure though if focus() and select() are actually needed.

This (live) example shows a short simple function, setCaretAtStartEnd, which takes two arguments; A (editable) node to place the caret at & a Boolean indicating where to place it (start or end of the node)

const editableElm = document.querySelector('[contenteditable]');

document.querySelectorAll('button').forEach((elm, idx) => 
  elm.addEventListener('click', () => {
    editableElm.focus()
    setCaretAtStartEnd(editableElm, idx) 
  })
)

function setCaretAtStartEnd( node, atEnd ){
  const sel = document.getSelection();
  node = node.firstChild;

  if( sel.rangeCount ){
      ['Start', 'End'].forEach(pos =>
        sel.getRangeAt(0)["set" + pos](node, atEnd ? node.length : 0)
      )
  }
}

[contenteditable]{ padding:5px; border:1px solid; }

<h1 contenteditable>Place the caret anywhere</h1>
<br>
<button>Move caret to start</button>
<button>Move caret to end</button>

If you are using the google closure compiler, you can do the following (somewhat simplified from Tim's answer):

function placeCaretAtEnd(el) {
    el.focus();
    range = goog.dom.Range.createFromNodeContents(el);
    range.collapse(false);
    range.select();
}

Here's the same thing in ClojureScript:

(defn place-caret-at-end [el] 
   (.focus el)
   (doto (.createFromNodeContents goog.dom.Range el)
         (.collapse false)
         .select))

I have tested this in Chrome, Safari and FireFox, not sure about IE...