The textarea editor is defined as below, no options required, but you can add any options in 'init' function.
textarea: {
	init: function(container, options){
		var input = $('<textarea class="datagrid-editable-input"></textarea>').appendTo(container);
		return input;
	},
	getValue: function(target){
		return $(target).val();
	},
	setValue: function(target, value){
		$(target).val(value);
	},
	resize: function(target, width){
		$(target)._outerWidth(width);
	}
}