Rails Regex Syntax

Question

Any Regex gurus out there? I have a position_id that is a string and can have the following formats. The number of digits can very, but is sort-of like so. all digits or digits and one dash '-'.

123456  or
123456-123

I need a regular expression that says, if position_id is not in that/those formats, throw a flag. I thought I had it with the following, but it doesn't seem to work. maybe my syntax is wrong.

if !params[:position_id] =~ /^\d+-?\d+$/
  flash[:error] = "error message here"
end

any help would be appreciated.

Anthony Alberto · Accepted Answer · 2013-04-04 18:13:43Z

1

It should work as long as you have at least 2 digits numbers. I guess you're testing it with 1 digits one?

If so, this should do it :

flash[:error] = "error message here" unless params[:position_id] =~ /^\d+(-\d+)?$/

We're making the whole -123 optional there

answered Apr 4, 2013 at 18:13

Anthony Alberto

10.4k3 gold badges36 silver badges39 bronze badges

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

4 Comments

John Cowan Over a year ago

actually, I'm testing with asdfsadfdsaf just to see if I can any error message back. Users should not be able to enter any non-digit characters other than the '-'. Should be just digits and maybe one dash.

Andrew Wei Over a year ago

generally speaking hyphens should be escaped

John Cowan Over a year ago

Hmmm all of the answers given work in the console. just not my controller. Grrrr! Thanks for the help though

Anthony Alberto Over a year ago

Then I'd log somewhere params[:position_id] to see if it's actually what you think it is!

Andrew Wei · Accepted Answer · 2013-04-04 18:46:41Z

0

Here is a simple one:

^([0-9]*)(\-[0-9]*)?$

http://rubular.com/r/2qSTHIPEo9

If you expect the number range to be a certain length just change it up as so:

^([0-9]{6})(\-[0-9]{3,4})?$

which says in words:

"any number thats 6 digits long"
"if there is a hyphen the second number must be between 3 and 4 digits"

http://rubular.com/r/5SHiJ1GKiK

EDIT: -- to answer the comment below

if !params[:position_id].match(/^([0-9]{6})(\-[0-9]{3,4})?$/)
    flash[:error] = "not valid"
end

http://ruby-doc.org/core-2.0/String.html#method-i-match

edited Apr 4, 2013 at 18:46

answered Apr 4, 2013 at 18:16

Andrew Wei

2,1201 gold badge18 silver badges30 bronze badges

1 Comment

John Cowan Over a year ago

I changed the code to just /\d/ and it won't catch on that with no digits. I test for params[:position_id].blank? so I know I have the param showing. Never had so much trouble on an easy regex.

Collectives™ on Stack Overflow

Rails Regex Syntax

2 Answers 2

4 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related