I have added a multifield component on page properties. I want to have a validation on the values entered in it by authors.
It is a textarea.
![goyalkritika_1-1699331630582.png goyalkritika_1-1699331630582.png](https://experienceleaguecommunities.adobe.com/t5/image/serverpage/image-id/65753i97096F325D89F233/image-size/medium?v=v2&px=400)
Validations: Author should be able to enter only numeric values and ',' in special characters. Also, there should be a maximum length of characters allowed in this textarea. Otherwise, it should throw a message in red color.
How can I write this custom validator?