Sort a collection of hash key-value pairs (e.g. facets returned from a Websolr search)

sortable_collection.rb

module SortableCollection
  class Sorter

    def self.sort_collection(collection, opts={})
      options = opts.select { |k,v| (k.in? valid_sorting_options) && (v.in? valid_sorters) }
      current_sorter = options[:sort_by].to_sym

      if options[:direction] == "asc"
        collection.sort { |a,b| a[current_sorter] <=> b[current_sorter] }
      else
        collection.sort { |a,b| b[current_sorter] <=> a[current_sorter] }
      end
    end

    def self.valid_sorting_options
      [:sort_by, :direction]
    end

    def self.valid_sorters
      %w(number_of_postings employer_name asc desc)
    end

  end
end