Pass field name as parameter to custom validation

问题:

I have a custom validation method:

def my_custom_validation
  errors.add(specific_field, "error message") if specific_field.delete_if { |i| i.blank? }.blank?
end

The goal is to disallow parameters which contains [""] pass through validation, but I need to call this method like:

validate :my_custom_validation #and somehow pass here my field names

For example:

 validate :my_custom_validation(:industry) 

回答1:

Since you need to validate multiple attributes this way I would recommend a custom validator like so:

class EmptyArrayValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    record.errors[attribute] << (options[:message] || "cannot be emtpy") if value.delete_if(&:blank?).empty?
  end
end

Then validate as

validates :industry, empty_array: true
validates :your_other_attribute, empty_array: true

Or if you don't want to specifically create a class because it is only needed for 1 model you could include this in the model itself

validates_each :industry, :your_other_attribute, :and_one_more do |record, attr, value|
  record.errors.add(attr, "cannot be emtpy") if value.delete_if(&:blank?).empty?
end