Contents

require 'fuzzily/trigram'

module Fuzzily
  module Searchable
    # fuzzily_searchable <field> [, <field>...] [, <options>]
    def fuzzily_searchable(*fields)
      options = fields.last.kind_of?(Hash) ? fields.pop : {}

      fields.each do |field|
        make_field_fuzzily_searchable(field, options)
      end
    end

    private

    def make_field_fuzzily_searchable(field, options={})
      class_variable_defined?(:"@@fuzzily_searchable_#{field}") and return

      trigram_class_name = options.fetch(:class_name, 'Trigram')
      trigram_association = "trigrams_for_#{field}".to_sym
      update_trigrams_method = "update_fuzzy_#{field}!".to_sym

      has_many trigram_association,
        :class_name => trigram_class_name,
        :as => :owner,
        :conditions => { :fuzzy_field => field.to_s },
        :dependent => :destroy

      singleton_class.send(:define_method,"find_by_fuzzy_#{field}".to_sym) do |*args|
        case args.size
          when 1 then pattern = args.first ; options = {}
          when 2 then pattern, options = args
          else        raise 'Wrong # of arguments'
        end
        Trigram.scoped(options).for_model(self.name).for_field(field).matches(pattern)
      end

      define_method update_trigrams_method do
        self.send(trigram_association).destroy_all
        self.send(field).extend(String).trigrams.each do |trigram|
          self.send(trigram_association).create!(:score => 1, :trigram => trigram)
        end
      end

      after_save do |record|
        next unless record.send("#{field}_changed?".to_sym)
        record.send(update_trigrams_method)
      end

      class_variable_set(:"@@fuzzily_searchable_#{field}", true)
      self
    end

  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
fuzzily-0.0.1	lib/fuzzily/searchable.rb