Cursor position in a textarea (character index, not x/y coordinates)

Solution 1:

Modified BojanG's solution to work with jQuery. Tested in Chrome, FF, and IE.

(function ($, undefined) {
    $.fn.getCursorPosition = function() {
        var el = $(this).get(0);
        var pos = 0;
        if('selectionStart' in el) {
            pos = el.selectionStart;
        } else if('selection' in document) {
            el.focus();
            var Sel = document.selection.createRange();
            var SelLength = document.selection.createRange().text.length;
            Sel.moveStart('character', -el.value.length);
            pos = Sel.text.length - SelLength;
        }
        return pos;
    }
})(jQuery);

Basically, to use it on a text box, do the following:

$("#myTextBoxSelector").getCursorPosition();

Solution 2:

function caretPos(el)
{
    var pos = 0;
    // IE Support
    if (document.selection) 
    {
        el.focus ();
        var Sel = document.selection.createRange();
        var SelLength = document.selection.createRange().text.length;
        Sel.moveStart ('character', -el.value.length);
        pos = Sel.text.length - SelLength;
    }
    // Firefox support
    else if (el.selectionStart || el.selectionStart == '0')
        pos = el.selectionStart;

    return pos;

}

Solution 3:

I have done some work using this jQuery masked input plug and found the caret function really useful. I've pulled this code from the above plugin..

$.fn.caret = function (begin, end)
    {
        if (this.length == 0) return;
        if (typeof begin == 'number')
        {
            end = (typeof end == 'number') ? end : begin;
            return this.each(function ()
            {
                if (this.setSelectionRange)
                {
                    this.setSelectionRange(begin, end);
                } else if (this.createTextRange)
                {
                    var range = this.createTextRange();
                    range.collapse(true);
                    range.moveEnd('character', end);
                    range.moveStart('character', begin);
                    try { range.select(); } catch (ex) { }
                }
            });
        } else
        {
            if (this[0].setSelectionRange)
            {
                begin = this[0].selectionStart;
                end = this[0].selectionEnd;
            } else if (document.selection && document.selection.createRange)
            {
                var range = document.selection.createRange();
                begin = 0 - range.duplicate().moveStart('character', -100000);
                end = begin + range.text.length;
            }
            return { begin: begin, end: end };
        }
    }

Once you've created the function you can do operations like the following. Once again, this function was pulled from the jQuery masked input function mentioned above.

$("#id").caret(); //get the begin/end caret position
$("#id").caret().begin;
$("#id").caret().end;
$("#otherId").caret(5); //set the caret position by index
$("#otherId").caret(1, 5); //select a range

Solution 4:

Not jQuery, but just Javascript...

var position = window.getSelection().getRangeAt(0).startOffset;