class ActiveRecord::Precounter
Constants
- VERSION
Public Class Methods
new(relation)
click to toggle source
@param [ActiveRecord::Relation] relation - Parent resources relation.
# File lib/active_record/precounter.rb, line 9 def initialize(relation) @relation = relation end
Public Instance Methods
precount(*association_names)
click to toggle source
@param [Array<String,Symbol>] association_names - Eager loaded association names. e.g. `[:users, :likes]` @return [Array<ActiveRecord::Base>]
# File lib/active_record/precounter.rb, line 15 def precount(*association_names) # Allow single record instances as well as relations to be passed. # The splat here will return an array of the single record if it's # not a relation or otherwise return the records themselves via #to_a. records = *@relation return records if records.empty? # We need to get the relation's active class, which is the class itself # in the case of a single record. klass = @relation.respond_to?(:klass) ? @relation.klass : @relation.class association_names.each do |association_name| association_name = association_name.to_s reflection = klass.reflections.fetch(association_name) if reflection.inverse_of.nil? raise MissingInverseOf.new( "`#{reflection.klass}` does not have inverse of `#{klass}##{reflection.name}`. "\ "Probably missing to call `#{reflection.klass}.belongs_to #{klass.name.underscore.to_sym.inspect}`?" ) end primary_key = reflection.inverse_of.association_primary_key.to_sym count_by_id = if reflection.has_scope? # ActiveRecord 5.0 unscopes #scope_for argument, so adding #where outside that: # https://github.com/rails/rails/blob/v5.0.7/activerecord/lib/active_record/reflection.rb#L314-L316 reflection.scope_for(reflection.klass.unscoped).where(reflection.inverse_of.name => records.map(&primary_key)).group( reflection.inverse_of.foreign_key ).count else reflection.klass.where(reflection.inverse_of.name => records.map(&primary_key)).group( reflection.inverse_of.foreign_key ).count end writer = define_count_accessor(klass, association_name) records.each do |record| record.public_send(writer, count_by_id.fetch(record.public_send(primary_key), 0)) end end records end
Private Instance Methods
define_count_accessor(klass, association_name)
click to toggle source
@param [Class] record class @param [String] association_name @return [String] writer method name
# File lib/active_record/precounter.rb, line 64 def define_count_accessor(klass, association_name) reader_name = "#{association_name}_count" writer_name = "#{reader_name}=" if !klass.method_defined?(reader_name) && !klass.method_defined?(writer_name) klass.extend(ActiveRecord::Precountable) klass.public_send(:precounts, association_name) end writer_name end