Rails：在 ActiveSupport::Concern 中使用辅助方法 (ActionView::Helpers::DateHelper) 用于 model

Question

I am trying to use the l method from ActionView::Helpers::DateHelper in a rails concern that is eventually included in a model.

I have this in my concern:

module SessionSupport
  extend ActiveSupport::Concern
  include ActionView::Helpers::DateHelper
  def dates_presenter
        "#{l(start_date, format: :short)} - #{l(end_dates, format: :short)}}"
  end
end

However I then get NoMethodError - undefined method l' for InstanceFromModelInWhichConcernIsIncluded`

How can I use a helper method inside a model concern?

Answer 1

Create your rails helper method

def l(val, opts = {})
   return nil unless val.present?
   value = val.to_date if val.is_a? String
   super(val, opts)
end

or

module SessionSupport
  extend ActiveSupport::Concern
  include ActionView::Helpers::DateHelper
  def dates_presenter
        "#{I18n.l(start_date, format: :short)} - #{I18n.l(end_dates, format: :short)}}"
  end
end

The most important methods of the I18n API are:

translate # Lookup text translations
localize  # Localize Date and Time objects to local formats

These have the aliases #t and #l so you can use them like this:

I18n.t 'store.title'
I18n.l Time.now