%r regex matching is ignoring my leading zeros

Ruby
1

Hello,

I hope someone can help me or at least confirm that I’m not going
insane.

I have a model in which I’m trying to validate information before it
saves.
One particular field is for and expiration date. The code in my model
to do the validation looks like this:

validates_format_of :expiration,
:with => %r{^[\d]{4,4}$},
:message => “must be formatted (mmyy)”

The problem is if someone enter a date that starts with a zero like
“0309” The validation somehow just doesn’t “see” the leading zero and
keeps returning an error as though the user isn’t submitting it
properly. I did verify that the controller is definetly sending all
four digits in the post.

I tried different combinations like: r{^(0|1)[\d]{3}$} but no matter
what I did the zero was ignored. I finally had to change it to look for
3 or 4 digits just to make it work but that of course isn’t proper
validation as my submissions must have 4 digits.

Can anyone help me? Am I going crazy here?

Thanks,
Dara

2

Dara Sanderson schrieb:

validates_format_of :expiration,
I tried different combinations like: r{^(0|1)[\d]{3}$} but no matter
what I did the zero was ignored. I finally had to change it to look for
3 or 4 digits just to make it work but that of course isn’t proper
validation as my submissions must have 4 digits.

Can anyone help me? Am I going crazy here?

Thanks,
Dara

i am not an expert in RE but don’t you think [\d]{4,4} should be
\d{4,4}

inside a class [] . and i think \ lose their special meaning

hth, Daniel

3

Hi –

On Thu, 30 Mar 2006, Dara Sanderson wrote:

validates_format_of :expiration,
I tried different combinations like: r{^(0|1)[\d]{3}$} but no matter
what I did the zero was ignored. I finally had to change it to look for
3 or 4 digits just to make it work but that of course isn’t proper
validation as my submissions must have 4 digits.

Can anyone help me? Am I going crazy here?

My guess is that somewhere along the line the month is being turned
into an integer and back to a string, so that “03” becomes 3 and then
“3”. I don’t know where, though.

David

–
David A. Black ([email protected])
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

“Ruby for Rails” chapters now available
from Manning Early Access Program! Ruby for Rails

4

Dara Sanderson ha scritto:

validates_format_of :expiration,
:with => %r{^[\d]{4,4}$},
:message => “must be formatted (mmyy)”

The problem is if someone enter a date that starts with a zero like
“0309” The validation somehow just doesn’t “see” the leading zero and
keeps returning an error as though the user isn’t submitting it
properly. I did verify that the controller is definetly sending all
four digits in the post.

I think I’d write the Regexp as:
%r{^\d{4}$}

Anyway, you one seem to work as expected on my box in irb:
irb(main):001:0> x=/^[\d]{4,4}$/
=> /^[\d]{4,4}$/
irb(main):002:0> x2=%r|^[\d]{4,4}$|
=> /^[\d]{4,4}$/
irb(main):003:0> x.match “0102”
=> #MatchData:0x2c0b300
irb(main):004:0> x2.match “0102”
=> #MatchData:0x2c08fa8

and in rails:
$cat app\models\foo.rb
class Foo < ActiveRecord::Base
validates_format_of :bar, :with=>%r{^\d{4}$}
end

f=Foo.new
=> #<Foo:0x39658e8 @new_record=true, @attributes={“bar”=>""}>

f.bar =“0123”
=> “0123”

f.save
=> true

f.bar =“012”
=> “012”

f.save
=> false

what version of ruby are you running?
Maybe it could have been some damn pesky problem like not having
reloaded the model (this happened to me many times :slight_smile: ?

5

First of all, thanks guys for trying to help.

I changed my model validation to remove the brackets from around the \d.
Still no dice.

When I tried it irb as Gabriele did it worked fine though. Just doesn’t
want to work on the actual form I’m using.

I’m afraid I dno’t know how to test rails as you have here:

and in rails:
$cat app\models\foo.rb
class Foo < ActiveRecord::Base
validates_format_of :bar, :with=>%r{^\d{4}$}
end

f=Foo.new
=> #<Foo:0x39658e8 @new_record=true, @attributes={“bar”=>""}>

f.bar =“0123”
=> “0123”

f.save
=> true

f.bar =“012”
=> “012”

f.save
=> false

what version of ruby are you running?
Maybe it could have been some damn pesky problem like not having
reloaded the model (this happened to me many times :slight_smile: ?

I’m hosted on Dreamhost so they’re on version 1.8.2 of ruby.

Maybe it does have something to do with conversion to a string. Maybe
I’ll try and manipulate it in my controller before saving.

Any other suggestions?

6

Dara Sanderson ha scritto:

First of all, thanks guys for trying to help.

I changed my model validation to remove the brackets from around the \d.
Still no dice.

When I tried it irb as Gabriele did it worked fine though. Just doesn’t
want to work on the actual form I’m using.

I’m afraid I dno’t know how to test rails as you have here:

this is just the the script/console thing in rails

Any other suggestions?
It seem that the problem is hitting before the validation against the
regex is actually called, the string is mangled somewhere.
Maybe you can try defining your own validation method and checking that
the value is the expected one, or if maybe it is truncated as david
black suggested.