HowTo : Columns for associations

Nested models may be added like this and do work for belongs_to associations

    def index  
      fancygrid_for :users do |user|
        # ...
        # insert associated models columns
        user.columns_for :contact do |contact|
          contact.attributes :email 
          # multiple nesting hierarchies are also supported
          contact.columns_for :person do |person|
            person.attributes :first_name, :last_name 
          end
        end

        user.find do |query|
          # the associated models always should be included in the search for eager loading.
          query.includes :contact => :person
        end
      end
    end

If you have Users that has_many Orders, you should rather define a fancygrid for the Orders than for Users. However, if it must be a Users table and you want to search on the associations attributes, you can do that:

    def index  
      fancygrid_for :users do |g|
        # ...
        g.columns_for :roles do |roles|
          roles.attributes :name 
        end
        # ...
      end
    end

The definition is valid, and you can already search for users with a specific role. But nothing is going to be rendered in the roles.name column. This is because roles is a collection of records, and not a single record. You can now format the column in the view like this

= fancygrid :users do |column, record, value|
  - case column.identifier
  - when "roles.name"
    = record.roles.map(&:name).join("|")
  - else
    = value