ASP.Net MVC regex for multi-line string

Question

I need to only allow following characters in multi-line textarea input field:

space, numbers, English letters and following special characters: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ ` [ \ ~ ] ^ _ { | }

I figured it out except the multi-line part:

        [RegularExpression("^[ -~]+$", ErrorMessage = @"Allowed characters for item description: space, numbers, English letters and following special characters: ! "" # $ % & ' ( ) * + , - . / : ; < = > ? @ ` [ \ ~ ] ^ _ {{ | }}")]

It works as desired as long as everything is entered as a single line. I just can't figure out how to extend it to multi-line.

@WiktorStribiżew: this is almost it. It works except if the very first or the very last line is an empty line — Joe Schmoe
– Joe Schmoe, Commented Jun 4, 2018 at 19:07
@JoeSchmoe What does that mean? That lines me be empty? Then use "^[ -~]*(?:\r?\n[ -~]*)*$" — Wiktor Stribiżew
– Wiktor Stribiżew, Commented Jun 4, 2018 at 19:10
@WiktorStribiżew: your second version seems to be working 100%. What I meant before: if I enter "ABC[Enter]DEF[Enter]" then it would not valdiate but now it does. If you post this as an answer I will mark it as such. — Joe Schmoe
– Joe Schmoe, Commented Jun 4, 2018 at 19:15

Wiktor Stribiżew · Accepted Answer · 2018-06-04 19:17:44Z

1

You may use

"^[ -~]*(?:\r?\n[ -~]*)*$"

The pattern matches:

^ - start of string
[ -~]* - 0 or more printable ASCII chars
(?: - start of a non-capturing group matching
- \r?\n - an optional (1 or 0) CR symbols and then an LF symbol (so that it matches Windows and Unix/Linux line endings)
- [ -~]* - 0 or more printable ASCII chars
)* - ... zero or more times
$ - end of string.

answered Jun 4, 2018 at 19:17

Wiktor Stribiżew

631k41 gold badges502 silver badges633 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

ASP.Net MVC regex for multi-line string

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related