How do I do elixir Regex instead of public Regex?

Questions / Help
1

Hi,
I was going to secure and valid email in my code, then I searched in google and found the Regex , but I can’t use this, because the # or … has been used in it.

public Regex :

[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?

and my code which not works :

	def validate_email(params) do
		Regex.match?(~r/[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?/, "#{params}")
	end

Please help me for converting it to elixir Regex. Thank you in advance for the sake of answering me.

2

Elixir sigils can use different delimiters. Since in your regex I didn’t see any <, > characters I used them as delimiters.

iex(15)> Regex.match?(~r<[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?>, "test")
false
iex(16)> Regex.match?(~r<[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?>, "user@example.com")
true

Otherwise you have to escape the the / character with \

~r/[a-z0-9!#$%&'*+\/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+\/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?/

I hope that is what you are after.

1 Like
3

Is my way correct?

{:ok ,  reg } = Regex.compile("[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?")

and

Regex.match?(reg)

Thanks

4

Except that Regex.match? has an arity of two

Regex.match?(reg, "my string")

your solution seems OK. It generates a regexp with the escaped version.

Maybe more experienced people can enlighten us with best practices.

1 Like
5

You should be very careful about validating email addresses with regex. My favourite approach is to “validate” it on the client (browser or app), and, if that verification fails, show a small “warning” note that the email address might not be valid (just so that the user might notice a possible typo) but allow to use it anyway and actually check it via email verification.

3 Likes
6

YES, PLEASE. I have a simple gmail userid since I joined early. There are close to a dozen people who have mistakenly given my email address instead of theirs for various services. The services that send a verification email that I ignore are awesome! The ones that assume they gave the right address are a pain.

3 Likes