Class: ActsAsXapian::Search

Inherits:
QueryBase show all
Defined in:
lib/acts_as_xapian/search.rb

Overview

Search for a query string, returns an array of hashes in result order. Each hash contains the actual Rails object in :model, and other detail about relevancy etc. in other keys.

Constant Summary collapse

@@parse_query_flags = 
Xapian::QueryParser::FLAG_BOOLEAN | Xapian::QueryParser::FLAG_PHRASE |
Xapian::QueryParser::FLAG_LOVEHATE | Xapian::QueryParser::FLAG_WILDCARD |
Xapian::QueryParser::FLAG_SPELLING_CORRECTION

Instance Attribute Summary collapse

Attributes inherited from QueryBase

#cached_results, #limit, #offset, #query, #query_models, #runtime

Instance Method Summary collapse

Methods inherited from QueryBase

#description, #matches, #matches_estimated, #results, #spelling_correction

Constructor Details

#initialize(model_classes, query_string, options = {}) ⇒ Search

model_classes - model classes to search within, e.g. [PublicBody, User]. Can take a single model class, or you can express the model class names in strings if you like. query_string - user inputed query string, with syntax much like Google Search

options include

  • :limit - limit the number of records returned

  • :offset - start with this record number

  • :check_at_least - used for total match estimates. Set higher for greater accuracy at the cost of slower queries. default: 100

  • :sort_by_prefix - determines which data field to sort by. default: sort by relevance

  • :sort_by_ascending - determines which direction to sort. default: true (ascending sort)

  • :collapse_by_prefix - groups the return set by this prefix

  • :find_options - These options are passed through to the active record find. Be careful if searching against multiple model classes.



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
 
# File 'lib/acts_as_xapian/search.rb', line 30

def initialize(model_classes, query_string, options = {})
  # Check parameters, convert to actual array of model classes
  model_classes = Array(model_classes).map do |model_class|
    model_class = model_class.constantize if model_class.instance_of?(String)
    raise "pass in the model class itself, or a string containing its name" unless model_class.instance_of?(Class)
    model_class
  end

  # Set things up
  self.initialize_db(model_classes)

  # Case of a string, searching for a Google-like syntax query
  self.query_string = query_string

  # Construct query which only finds things from specified models
  model_query = Xapian::Query.new(Xapian::Query::OP_OR, model_classes.map {|mc| "M#{mc}" })
  user_query = @index.query_parser.parse_query(self.query_string, @@parse_query_flags)
  self.query = Xapian::Query.new(Xapian::Query::OP_AND, model_query, user_query)

  # Call base class constructor
  self.initialize_query(options)
end

Instance Attribute Details

#query_string ⇒ Object

Returns the value of attribute query_string.



6
7
8
 
# File 'lib/acts_as_xapian/search.rb', line 6

def query_string
  @query_string
end

Instance Method Details

#log_description ⇒ Object

Text for lines in log file



63
64
65
 
# File 'lib/acts_as_xapian/search.rb', line 63

def log_description
  "Search: #{self.query_string}"
end

#words_to_highlight ⇒ Object

Return just normal words in the query i.e. Not operators, ones in date ranges or similar. Use this for cheap highlighting with TextHelper::highlight, and excerpt.



56
57
58
59
60
 
# File 'lib/acts_as_xapian/search.rb', line 56

def words_to_highlight
  query_nopunc = self.query_string.gsub(/[^\w:\.\/_]/i, " ").gsub(/\s+/, " ")
  # Split on ' ' and remove anything with a :, . or / in it or boolean operators
  query_nopunc.split(" ").reject {|o| o.match(/(:|\.|\/)|^(AND|NOT|OR|XOR)$/) }
end