我有 3 个这样的模型：
class CertificatorBtwInstructor < ActiveRecord::Base
belongs_to :certificator
belongs_to :instructor
# other code ...
end
class Certificator < ActiveRecord::Base
has_many :btw_instructors, :class_name => "CertificatorBtwInstructor"
has_many :instructors, :through => :btw_instructors
# other code ...
end
class Instructor < ActiveRecord::Base
has_many :btw_certificators, :class_name => "CertificatorBtwInstructor"
has_many :certificators, :through => :btw_certificators
# other code ...
end
在我的讲师新表格上，我设置了：
= simple_form_for( [:cm, @instructor], :html => { :class => "fAdm" } ) do |f|
= f.object.errors
- others fields ...
= f.input :certificator_ids, :required => false, :collection => Certificator.choices_relation_select, :input_html => { :multiple => true, :size => 12 }
%div.row.buttons
= f.button :submit
然后，当我提交表单而不从“certificator_ids”输入集合中选择任何证书时，新记录的创建没有问题。但是，当我在“certificator_ids”输入集合中选择任何项目时，会出现一个错误（我用 = f.object.errors 将其可视化），错误是这样的：
{:certificators=>["is not valid"]}
但在我的表单上，我没有设置“验证者”字段，所以我不明白他们为什么得到这个属性。