Class: XapianDb::Adapters::BaseAdapter

Inherits:
Object
  • Object
show all
Defined in:
lib/xapian_db/adapters/base_adapter.rb

Overview

base class for all adapters. This adapter does the following:

  • adds the class method search(expression) to an indexed class

Author:

  • Gernot Kogler

Class Method Summary collapse

Class Method Details

.add_class_helper_methods_to(klass) ⇒ Object

Implement the class helper methods

Parameters:

  • klass (Class) —

    The class to add the helper methods to



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# File 'lib/xapian_db/adapters/base_adapter.rb', line 17

def add_class_helper_methods_to(klass)

  klass.class_eval do

    # Add a method to search models of this class
    # Options:
    # - :order          (Array<Symbol>) Accepts an array of attribute names for sorting
    # - :sort_decending (Boolean)       Allows to reverse the sorting
    define_singleton_method(:search) do |expression, options={}|

      # return an empty search if no search expression is given
      return XapianDb.database.search(nil) if expression.nil? || expression.strip.empty?

      options = {:sort_decending => false}.merge options
      class_scope = "indexed_class:#{klass.name.downcase}"

      order = options.delete :order
      if order
        attr_names             = [order].flatten
        undefined_attrs        = attr_names - XapianDb::DocumentBlueprint.attributes
        raise ArgumentError.new "invalid order clause: attributes #{undefined_attrs.inspect} are not defined" unless undefined_attrs.empty?
        options[:sort_indices] = attr_names.map {|attr_name| XapianDb::DocumentBlueprint.value_number_for(attr_name) }
      end
      result = XapianDb.database.search "#{class_scope} AND (#{expression})", options

      # Remove the class scope from the spelling suggestion (if any)
      if result.spelling_suggestion
        scope_length = "#{class_scope} AND (".size
        result.spelling_suggestion = result.spelling_suggestion.slice scope_length..-2
      end
      result
    end

    define_singleton_method(:find_similar_to) do |reference|
     return XapianDb.database.find_similar_to reference, :class => klass
    end

    # Add a method to search atribute facets of this class
    define_singleton_method(:facets) do |attribute, expression|
      class_scope  = "indexed_class:#{klass.name.downcase}"
      XapianDb.database.facets attribute, "#{class_scope} and (#{expression})"
    end

  end
end