在Rails中使用参数调用模型方法

Question

I have the following problem, lets say I have a table Users and a second table UserStrings for localization. UserStrings has the following columns {user_id, language_id, full_name}

I also have a current_language method in ApplicationController that returns the id of the current language.

I have to use a collection_select and I need to display user names of current language in the list.

<%= fb.collection_select(:id, User.all,:id, :full_name, {}, {})%>

The thing is that there is no full_name column in User table. I know its possible to make a model method and call it instead of name.

<%= fb.collection_select(:id, User.all,:id, :model_method, {}, {})%>

This model method I wanted to run this little line

self.user_strings.find_by(:language_id => current_language).full_name

Here is the problem, I know that it is not possible to use a controller method in Models so I cant get the current_language in my Model. Is it possible to call the :model_method with param (current_language). If not is there any other way to get this working?

ps. And no its not possible to rewrite the current_language as a new model method in Model because is more complex than it seems.

Thanks in advance!

Answer 1

Try this

        def method_missing(m, *args, &block)  
             match = m.to_s.match(/regex of languages here/)
              if match
                self.user_strings.find_by(:language_id => match).first_name + self.user_strings.find_by(:language_id => match).last_name
              else
               nil
             end
      end  

You can not it directly you need to define dynamic method for that

Answer 2

collection_select also accepts a Proc in place of a method name ( docs ).

I haven't been able to try it out, but this should work:

<%= fb.collection_select(:id, User.all,:id, Proc.new{ model_method(current_language) }, {}, {})%>