[英]Rails: validate presence of foo unless bar == 'baz'
I'm working on a model that has two associations that need to be set when an object is created, EXCEPT in one case. 我正在研究一个模型,该模型在创建对象时需要设置两个关联,在一种情况下除外。
Basically, it needs to work like this. 基本上,它需要像这样工作。
class Example < ActiveRecord::Base
has_one :foo
has_one :bar
validates_presence_of :foo
validates_presence_of :bar, :unless => :foo == Foo.find_by_name('ThisFooDoesntLikeBars')
end
I'm not sure how to build the :unless condition here, as it needs to check whether :foo is a specific object or not. 我不确定如何构建:除非条件在这里,因为它需要检查:foo是否是特定对象。
How do you do something like this? 你怎么做这样的事情?
:unless
accepts a Proc :unless
接受Proc
validates_presence_of :bar, :unless => Proc.new { |ex| ex.foo == Foo.find_by_name('ThisFooDoesntLikeBars') }
:unless - Specifies a method, proc or string to call to determine if the validation should not occur (eg :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }).
:unless - 指定要调用的方法,proc或字符串,以确定是否不应进行验证(例如:unless =>:skip_validation,或:unless => Proc.new {| user | user.signup_step <= 2})。 The method, proc or string should return or evaluate to a true or false value.
方法,proc或string应返回或计算为true或false值。
http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html
How about the following: 以下内容如何:
class Example < ActiveRecord::Base
has_one :foo
has_one :bar
validates_presence_of :foo
validates_presence_of :bar, :unless => Proc.new { |example| example.foo == Foo.find_by_name('ThisFooDoesntLikeBars') }
end
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