Hello there,
I have the following Book model, where users can enter the Title of
the book and optionally the format of the ISBN-code shall be
validated, but only if the user filled the ISBN field:
class Book < ActiveRecord::Base
associations
belongs_to :user, :counter_cache => true
validations
validates_presence_of :title
validates_format_of :isbn, :with => /[0-9-a-zA-Z]{10}|[0-9-a-zA-Z]
{13}/, :allow_nil => true
validates_existence_of :user
attr_protected :user_id
end
When I create a book on the console sans ISBN code, it works perfectly
fine:
b = Book.new
=> #<Book id: nil, title: nil, author: nil, isbn: nil, description:
nil, user_id: nil, created_at: nil, updated_at: nil>b.user_id = 1
=> 1b.title = “Book #1”
=> “Book #1”b.save
=> true
When I enter a non isbn-10 or isbn-13 code, it properly raises the
error:
b.title = “Book #2”
=> “Book #2”b.isbn = “abc”
=> “abc”b.save
=> falseb.errors
=> #<ActiveRecord::Errors:0x2409564 @base=#<Book id: nil, title: “Book
#2”, author: nil, isbn: “abc”, description: nil, user_id: 1,
created_at: nil, updated_at: nil>, @errors={“isbn”=>[“is invalid”]}>
So far so good. Now when I do the same in the browser & create an ISBN-
less book, it says:
1 error prohibited this book from being saved
There were problems with the following fields:
Isbn is invalid
And the params looking like this:
{“commit”=>“Create”,
“authenticity_token”=>“5c27df353e84da4378277ff8201bcacdb394a0d4”,
“action”=>“create”, “controller”=>“books”, “user_id”=>“1”,
“book”=>{“isbn”=>"", “title”=>“abc”, “author”=>"", “description”=>""}}
Why is this? Shouldn’t :allow_nil work there, too?
Or did I miss something?
-J