This clears up everything :-) I do have the free chapter, and am subscribed to his weekly emails. I just need to take the time to sit down and read everything. His blog posts are very helpful though.
Again, thank you for the help!! :D On Friday, September 18, 2015 at 9:36:31 AM UTC-4, tamouse wrote: > > On Thu, Sep 17, 2015 at 2:44 PM, Hunter Stevens <[email protected] > <javascript:>> wrote: > > The docs I was referring to were Rails Guides, which I take for > > granted as THE docs. Thank you for the appropriate link! > > The Guides are great, but definitely not all the documentation! :) The > api documentation is probably more vital to understanding how Rails > actually works; after that it's straight into the code. :) > > > Finally, just to clarify (because I want to make sure I understand): > > > > 1. The database allows NULL for :number_of_extensions > > 2. The sub-model requires :number_of_extensions to NOT be nil or blank > > 3. The sub model requires :number_of_extensions to be a [whole] number >0 > > > > Given that information, if I only check validity for numericality, > > does Rails implicitly accept that as "must be present"? Because it > > is crucial that the database must allow null for all cases, but that > > Rails does not accept nil for this particular sub-model. > > The `validates_numericality_of` method has a few options, as you've > seen. There are two that are important here, notably by *not* using > them in your validation: > > * `allow_nil` -- if you set this explicitly to `false` or leave out as > the default is `false`, that will ensure that the value under test > *must* not be nil, i.e., must be present. > > * `allow_blank` -- like `allow_nil` but also allows in the case of a > numerical test a "blank" value, i.e., an empty string. Again, > explicitly setting it to `false` or leaving it out as the default is > `false` will ensure that your value under test cannot be an empty > string. > > I'm pretty sure that covers the gamut of your needs, so to make it > explicit, this is what you should have: > > validates_numericality_of :number_of_extensions, { only_integer: true, > greater_than: 0} > > And that will ensure the number of extensions MUST be a positive, > whole number and can NOT be nil. > > > Thank you for the help so far > > My pleasure. :) > > If you'll indulge me in a little more exposition, read Justin Weiss's > ["Practicing Rails"](https://www.justinweiss.com/practicing-rails/), > most especially the first (free!) chapter, which > defines exquisitely a practice of learning something. Breaking things > down into a small, learnable chunk, by spooling up a small rails app > expressly for that chunk serves me so well in studying, playing around > with, explaining, and so on. Coupled with playing around in the rails > console, especially when using pry, helps so much. It becomes easier > to just try stuff out and see how it works, or doesn't! > > > On Thursday, September 17, 2015 at 8:20:37 AM UTC-4, tamouse wrote: > > > On Wed, Sep 16, 2015 at 9:54 AM, Hunter Stevens <[email protected]> > wrote: > > > > Hello. I know the title may be broad, but I am not sure how else to > put it. > > > > > > > > I am writing a model, in which the attribute "number_of_extensions" > needs 2 things: > > > > 1. It is required for this model > > > > 2. It must be a whole, positive number > > > > > > > > I know I can do this simply by > > > > > > > > validates :number_of_extensions, presence: true, numericality: { > only_integer: true } > > > > > > > > However, if I validate for JUST numericality, is it assumed that > > > > the attribute SHOULD be present? > > > > > > That is so; there is an option to allow nil or blank, but it is > > > false by default. As it needs to be positive, you should also > > > specify `greater_than: 0` in the options hash. > > > > > > > Also, while I am talking about validations, I have another question: > > > > > > > > I know that the following type of validations is not in the docs > > > > anymore, but it is still supported. Would the following line be > > > > possible? > > > > > > > > validates_numericality_of :number_of_extensions, > :number_of_sidecars, :number_of_phones, only_integer: true > > > > > > I'm pretty sure that is still in: > > > > > > > http://api.rubyonrails.org/classes/ActiveModel/Validations/HelperMethods.html#method-i-validates_numericality_of > > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/f5b8b360-b294-434c-91c0-5240afc8809b%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
