DRY AjaxDatatablesRails

core_ajax_datatables.rb

class CoreAjaxDatatables < AjaxDatatablesRails::Base

  def_delegators :@view, :link_to, :font_icon, :h

  def sortable_columns
    @sortable_columns ||= datatable_columns
  end

  def searchable_columns
    @searchable_columns ||= datatable_columns
  end

  class << self

    def model_name
      name.gsub('Datatable', '')
    end

    def model
      model_name.constantize
    end

  end

  private

    def data
      records.map do |record|
        attributes.map do |attr|
          if attr.is_a?(Hash) && attr[:formatter]
            value = record.send(attr[:name])
            text = record.send(attr[:formatter])
            h("<span data-search-value='#{value}'>#{text}</span>".html_safe)
          else
            h(record.send(attr))
          end
        end << *action_links(record)
      end
    end

    def find_raw_records
      self.class.model.all
    end
    alias get_raw_records find_raw_records

    def datatable_columns
      attributes.map do |attr|
        "#{self.class.model_name}.#{attr.is_a?(Hash) && attr[:formatter] ? attr[:name] : attr}"
      end
    end

end

TODO.txt

# TODOs
1. Support for associated models
2. Support for serielized models
3. Enable/disable search/sort for particular column

user.rb

class User < ActiveRecord::Base

  def formatted_country
    # custom code to generate foramtted country. For example including flag and country name
  end

end

user_datatable.rb

class UserDatatable < CoreAjaxDatatables

  def_delegators :@view, :user_path, :edit_user_path

  private

    def attributes
      ['first_name', 'last_name', { name: 'country_id', formatter: 'formatted_country' }]
    end

    def action_links(record)
      [
        link_to('Show', user_path(record)),
        (record.archived? ? '' : link_to('Edit', edit_package_path(record))),
        (record.archived? ? '' : link_to('Delete', user_path(record), method: :delete, data: { confirm: 'Are you sure?' }))
      ]
    end

    # can be overridden if needed
    def find_raw_records 
      # custom query code
    end

    # can be overridden if needed
    def datatable_columns
      # different code than generated in CoreAjaxDatatables
    end

end