Get cursor position (in characters) within a text Input field

MarkB29 picture MarkB29 · May 24, 2010 · Viewed 288.3k times · Source

How can I get the caret position from within an input field?

I have found a few bits and pieces via Google, but nothing bullet proof.

Basically something like a jQuery plugin would be ideal, so I could simply do

$("#myinput").caretPosition()

Answer

bezmax picture bezmax · May 24, 2010

Easier update:

Use field.selectionStart example in this answer.

Thanks to @commonSenseCode for pointing this out.


Old answer:

Found this solution. Not jquery based but there is no problem to integrate it to jquery:

/*
** Returns the caret (cursor) position of the specified text field (oField).
** Return value range is 0-oField.value.length.
*/
function doGetCaretPosition (oField) {

  // Initialize
  var iCaretPos = 0;

  // IE Support
  if (document.selection) {

    // Set focus on the element
    oField.focus();

    // To get cursor position, get empty selection range
    var oSel = document.selection.createRange();

    // Move selection start to 0 position
    oSel.moveStart('character', -oField.value.length);

    // The caret position is selection length
    iCaretPos = oSel.text.length;
  }

  // Firefox support
  else if (oField.selectionStart || oField.selectionStart == '0')
    iCaretPos = oField.selectionDirection=='backward' ? oField.selectionStart : oField.selectionEnd;

  // Return results
  return iCaretPos;
}