How Can I Set the Cursor Position in a jQuery Text Area?

jQuery Set Cursor Position in Text Area

Challenge:

Need a method to set the cursor position in a text area using jQuery. The desired behavior is to position the cursor at a specific offset when the field is focused.

jQuery Solution:

$.fn.setCursorPosition = function(pos) {
  if (this.setSelectionRange) {
    this.setSelectionRange(pos, pos);
  } else if (this.createTextRange) {
    var range = this.createTextRange();
    range.collapse(true);
    if (pos < 0) {
      pos = $(this).val().length + pos;
    }
    range.moveEnd("character", pos);
    range.moveStart("character", pos);
    range.select();
  }
};

Usage:

$('#input').focus(function() {
  $(this).setCursorPosition(4);
});

This would position the cursor after the fourth character in the text field.

Alternative Solution:

$.fn.selectRange = function(start, end) {
  if (end === undefined) {
    end = start;
  }
  return this.each(function() {
    if ("selectionStart" in this) {
      this.selectionStart = start;
      this.selectionEnd = end;
    } else if (this.setSelectionRange) {
      this.setSelectionRange(start, end);
    } else if (this.createTextRange) {
      var range = this.createTextRange();
      range.collapse(true);
      range.moveEnd("character", end);
      range.moveStart("character", start);
      range.select();
    }
  });
};

This allows for more versatile text selection, including selecting a range of characters:

$('#elem').selectRange(3, 5); // select a range of text
$('#elem').selectRange(3); // set cursor position

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