Attribute to Prevent Slash (/) and Backslash (\)?

Question

I have a text field property where I do not want users to be able to enter forward or back slashes. Is there a data attribute for this or do I need to use the RegularExpression attribute?

This seems like it would be pretty common, but I am not having any luck finding the answer. I'm not familiar with Regular Expressions, so I'm researching them now.

Answer 1

You can use the RegularExpressionAttribute for this:

[RegularExpression(@"^[^\\/]*$")]

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To break the regex down:

^ ... $

The ^ and $ respectively denote the beginning and the end of the field. This wrapper forces the entire string to match the regex to validate.

[^ ... ]*

This is a negated character class that can occur zero or more times. To match, the string must not contain any of the characters inside this container.

\\
/

The first character, the backslash, must be escaped. The forward slash must not.

Once you put it all together, you have a regex that states that nowhere in the string can you have a backslash or a forward slash.

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Here, try it out on Debuggex.