Attributes - eternally useful when it comes to filtering, sorting or grouping. This class isn’t really useful to you unless you’re hacking around with the internals of Thinking Sphinx - but hey, don’t let that stop you.
One key thing to remember - if you’re using the attribute manually to generate SQL statements, you’ll need to set the base model, and all the associations. Which can get messy. Use Index.link!, it really helps.
To create a new attribute, you’ll need to pass in either a single Column or an array of them, and some (optional) options.
Valid options are:
:as => :alias_name
:type => :attribute_type
:source => :field, :query, :ranged_query
Alias is only required in three circumstances: when there’s another attribute or field with the same name, when the column name is ‘id’, or when there’s more than one column.
Type is not required, unless you want to force a column to be a certain type (but keep in mind the value will not be CASTed in the SQL statements). The only time you really need to use this is when the type can’t be figured out by the column - ie: when not actually using a database column as your source.
Source is only used for multi-value attributes (MVA). By default this will use a left-join and a group_concat to obtain the values. For better performance during indexing it can be beneficial to let Sphinx use a separate query to retrieve all document,value-pairs. Either :query or :ranged_query will enable this feature, where :ranged_query will cause the query to be executed incremental.
Example usage:
Attribute.new( Column.new(:created_at) ) Attribute.new( Column.new(:posts, :id), :as => :post_ids ) Attribute.new( Column.new(:posts, :id), :as => :post_ids, :source => :ranged_query ) Attribute.new( [Column.new(:pages, :id), Column.new(:articles, :id)], :as => :content_ids ) Attribute.new( Column.new("NOW()"), :as => :indexed_at, :type => :datetime )
If you’re creating attributes for latitude and longitude, don’t forget that Sphinx expects these values to be in radians.
# File lib/thinking_sphinx/attribute.rb, line 81 def initialize(source, columns, options = {}) super @type = options[:type] @query_source = options[:source] @crc = options[:crc] @all_ints = options[:all_ints] @type ||= :multi unless @query_source.nil? if @type == :string && @crc @type = is_many? ? :multi : :integer end source.attributes << self end
# File lib/thinking_sphinx/attribute.rb, line 201 def all_datetimes? all_of_type?(:datetime, :date, :timestamp) end
# File lib/thinking_sphinx/attribute.rb, line 197 def all_ints? @all_ints || all_of_type?(:integer) end
# File lib/thinking_sphinx/attribute.rb, line 205 def all_strings? all_of_type?(:string, :text) end
Returns the configuration value that should be used for the attribute. Special case is the multi-valued attribute that needs some extra configuration.
# File lib/thinking_sphinx/attribute.rb, line 144 def config_value(offset = nil, delta = false) if type == :multi multi_config = include_as_association? ? "field" : source_value(offset, delta).gsub(%r\s+/, " ").strip "uint #{unique_name} from #{multi_config}" else unique_name end end
# File lib/thinking_sphinx/attribute.rb, line 135 def include_as_association? ! (type == :multi && (query_source == :query || query_source == :ranged_query)) end
# File lib/thinking_sphinx/attribute.rb, line 186 def live_value(instance) object = instance column = @columns.first column.__stack.each { |method| object = object.send(method) return sphinx_value(nil) if object.nil? } sphinx_value object.send(column.__name) end
Get the part of the SELECT clause related to this attribute. Don’t forget to set your model and associations first though.
This will concatenate strings and arrays of integers, and convert datetimes to timestamps, as needed.
# File lib/thinking_sphinx/attribute.rb, line 103 def to_select_sql return nil unless include_as_association? && available? separator = all_ints? || all_datetimes? || @crc ? ',' : ' ' clause = columns_with_prefixes.collect { |column| case type when :string adapter.convert_nulls(column) when :datetime adapter.cast_to_datetime(column) when :multi column = adapter.cast_to_datetime(column) if is_many_datetimes? column = adapter.convert_nulls(column, '0') if is_many_ints? column else column end }.join(', ') clause = adapter.crc(clause) if @crc clause = adapter.concatenate(clause, separator) if concat_ws? clause = adapter.group_concatenate(clause, separator) if is_many? clause = adapter.downcase(clause) if insensitive? "#{clause} AS #{quote_column(unique_name)}" end
Returns the type of the column. If that’s not already set, it returns :multi if there’s the possibility of more than one value, :string if there’s more than one association, otherwise it figures out what the actual column’s datatype is and returns that.
# File lib/thinking_sphinx/attribute.rb, line 159 def type @type ||= begin base_type = case when is_many?, is_many_ints? :multi when @associations.values.flatten.length > 1 :string else translated_type_from_database end if base_type == :string && @crc base_type = :integer else @crc = false unless base_type == :multi && is_many_strings? && @crc end base_type end end
# File lib/thinking_sphinx/attribute.rb, line 131 def type_to_config SphinxTypeMappings[type] end
# File lib/thinking_sphinx/attribute.rb, line 180 def updatable? [:integer, :datetime, :boolean].include?(type) && unique_name != :sphinx_internal_id && !is_string? end