method

generate_message

v6.0.0 - Show latest stable - Class: ActiveModel::Errors

generate_message(attribute, type = :invalid, options = {})

public

Translates an error message in its default scope (activemodel.errors.messages).

Error messages are first looked up in activemodel.errors.models.MODEL.attributes.ATTRIBUTE.MESSAGE, if it’s not there, it’s looked up in activemodel.errors.models.MODEL.MESSAGE and if that is not there also, it returns the translation of the default message (e.g. activemodel.errors.messages.MESSAGE). The translated model name, translated attribute name and the value are available for interpolation.

When using inheritance in your models, it will check all the inherited models too, but only if the model itself hasn’t been found. Say you have class Admin < User; end and you wanted the translation for the :blank error message for the title attribute, it looks for these translations:

activemodel.errors.models.admin.attributes.title.blank
activemodel.errors.models.admin.blank
activemodel.errors.models.user.attributes.title.blank
activemodel.errors.models.user.blank
any default you provided through the options hash (in the activemodel.errors scope)
activemodel.errors.messages.blank
errors.attributes.title.blank
errors.messages.blank

# File activemodel/lib/active_model/errors.rb, line 480
    def generate_message(attribute, type = :invalid, options = {})
      type = options.delete(:message) if options[:message].is_a?(Symbol)
      value = (attribute != :base ? @base.send(:read_attribute_for_validation, attribute) : nil)

      options = {
        model: @base.model_name.human,
        attribute: @base.class.human_attribute_name(attribute),
        value: value,
        object: @base
      }.merge!(options)

      if @base.class.respond_to?(:i18n_scope)
        i18n_scope = @base.class.i18n_scope.to_s
        defaults = @base.class.lookup_ancestors.flat_map do |klass|
          [ :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.attributes.#{attribute}.#{type}",
            :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.#{type}" ]
        end
        defaults << :"#{i18n_scope}.errors.messages.#{type}"

        catch(:exception) do
          translation = I18n.translate(defaults.first, options.merge(default: defaults.drop(1), throw: true))
          return translation unless translation.nil?
        end unless options[:message]
      else
        defaults = []
      end

      defaults << :"errors.attributes.#{attribute}.#{type}"
      defaults << :"errors.messages.#{type}"

      key = defaults.shift
      defaults = options.delete(:message) if options[:message]
      options[:default] = defaults

      I18n.translate(key, options)
    end

generate_message

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