Allowing line breaks \n

[robinNavas]

Hi,

I am quite a newbie in fields validation and I am struggling with the validation of a textarea form field. I use the alnum(" ") rule but when I add a line break in the field the validation fails because there is \n characters included in the value. I can't figure out how to add them to the alnum rule, I have test alnum(' \ \n') with no result.

I wonder what is the best solution to validate this type of data.

Thank's, and sorry this is certainly a very basic question but I am quite blocked right now.