# RE: \[Best Practices\] phone numbers?

**URL:** <https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122>\
**Category:** Rails\
**Created:** [July 12, 2006, 5:38pm UTC](https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122 "2006-07-12T17:38:11Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![nathandelane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/df705f/32.png) [@nathandelane](https://www.ruby-forum.com/u/nathandelane)\
**Post date:** [July 12, 2006, 5:38pm UTC](https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122/1 "2006-07-12T17:38:11Z")

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Sounds like a chance for an expert to create a phone number class  
(plugin, etc.) that we can all use…maybe with a simple parameter like  
country to drive the output formatting.

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**Author:** ![nathandelane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/df705f/32.png) [@nathandelane](https://www.ruby-forum.com/u/nathandelane)\
**Post date:** [July 12, 2006, 7:34pm UTC](https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122/2 "2006-07-12T19:34:50Z")

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Thanks for all the replies. My conclusions are these:

1. Users make mistakes, and don’t always format the entries the same  
way.  
ie. (253)111-2222 vs 253/111-2222 vs 253-111-2222 or ever (253)  
111-2222  
x48996 { for US phone nbrs}. The inconsistancy bothers me.

2. Pragmatically speaking. It is worth the effort control to validate  
the  
phone numbers? In this case, not really. Humans will be able to read  
them. That’s what matters most. Agile Programming methodology says  
don’t  
implement more than you need to, (or something like that).

3. A plugin would be nice. Something to look into when I have time.  
Unless someone beats me to it 🙂  
-Larry

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**Author:** ![nathandelane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/df705f/32.png) [@nathandelane](https://www.ruby-forum.com/u/nathandelane)\
**Post date:** [July 12, 2006, 7:41pm UTC](https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122/3 "2006-07-12T19:41:12Z")

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Customers really like putting in numbers THEIR way.

So, store what they enter for view and editing, as  
well as a normalized version to operate on internally.

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**Author:** ![nathandelane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/df705f/32.png) [@nathandelane](https://www.ruby-forum.com/u/nathandelane)\
**Post date:** [July 12, 2006, 8:19pm UTC](https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122/4 "2006-07-12T20:19:57Z")

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On Wed, Jul 12, 2006, Larry K. wrote:

> Thanks for all the replies. My conclusions are these:
> 
> 1. Users make mistakes, and don’t always format the entries the same way.  
> ie. (253)111-2222 vs 253/111-2222 vs 253-111-2222 or ever (253) 111-2222  
> x48996 { for US phone nbrs}. The inconsistancy bothers me.

Yeah, you have to get over that. Just let them enter whatever they  
like, run your validation, and store it as-entered. Or do crazy  
munging, it’s up to you 🙂

> 1. Pragmatically speaking. It is worth the effort control to validate the  
> phone numbers? In this case, not really. Humans will be able to read  
> them. That’s what matters most. Agile Programming methodology says don’t  
> implement more than you need to, (or something like that).

It’s easy to validate US number. Strip out everything that’s not a  
digit, strip off leading 0s and 1s, and make sure the result is at least  
10 digits long. I’d say writing those two regular expressions is worth  
it 😉

Ben

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**Author:** ![nathandelane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/df705f/32.png) [@nathandelane](https://www.ruby-forum.com/u/nathandelane)\
**Post date:** [July 12, 2006, 9:02pm UTC](https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122/5 "2006-07-12T21:02:35Z")

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(joining this conversation late)

I have found the following to effective:

1. allow users to enter data the way they want (support multiple  
methods)
2. validate all formats you support (add them as users require)
3. normalize the data before insert (update)
4. on retrieve, standardize the data (good place for  
internationalization)

All work is done in the model.

(this code was previously posted, and criticized for being not  
factored enough. feel free to implement the concept as you feel it  
requires. grin)

Hopefully you can use this pattern - Works well for postalcodes  
(zips), dates, and other key High Value data.

class Contact \< ActiveRecord::Base

protected  
#validate the phone formats accepted  
def validate  
if errors.on(“phone”).nil?  
validate\_phone = self.phone\_before\_type\_cast.gsub(/[^0-9]/,"")  
if !validate\_phone.nil? and validate\_phone.length != 7 and  
validate\_phone.length != 10  
errors.add(“phone”, “number is not correct. Either a 7 or  
10 digit phone # must be specified.”)  
end  
end  
end

#format the phone number for display  
def after\_find  
self.phone = “#{self.phone\_before\_type\_cast[0…2]}-#  
{self.phone\_before\_type\_cast[3…6]}” if !self.phone.nil? and  
self.phone\_before\_type\_cast.length == 7  
self.phone = “(#{self.phone\_before\_type\_cast[0…2]}) #  
{self.phone\_before\_type\_cast[3…5]}-#{self.phone\_before\_type\_cast  
[6…9]}” if !self.phone.nil? and self.phone\_before\_type\_cast.length  
== 10  
end

#remove all non-numbers  
def before\_save  
self.phone\_before\_type\_cast.gsub!(/[^0-9]/,"") if !self.phone.nil?  
end

…  
end

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<div class="post-metadata">

**Author:** ![nathandelane](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/df705f/32.png) [@nathandelane](https://www.ruby-forum.com/u/nathandelane)\
**Post date:** [July 12, 2006, 9:06pm UTC](https://www.ruby-forum.com/t/re-best-practices-phone-numbers/98122/6 "2006-07-12T21:06:15Z")

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> > them. That’s what matters most. Agile Programming methodology says don’t  
> > implement more than you need to, (or something like that).
> 
> It’s easy to validate US number. Strip out everything that’s not a  
> digit, strip off leading 0s and 1s, and make sure the result is at least  
> 10 digits long. I’d say writing those two regular expressions is worth  
> it 😉

My old phone number would pass… 352-2554 x204, but you still have no  
idea what the area code is… just something to keep in mind…