Module: CompositePrimaryKeys::ActiveRecord::AssociationPreload::ClassMethods

Defined in:
lib/composite_primary_keys/association_preload.rb

Overview

Composite key versions of Association functions

Instance Method Summary collapse

Instance Method Details

#find_associated_records(ids, reflection, preload_options) ⇒ Object 



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# File 'lib/composite_primary_keys/association_preload.rb', line 112

def find_associated_records(ids, reflection, preload_options)
  options = reflection.options
  table_name = reflection.klass.quoted_table_name

  if interface = reflection.options[:as]
    conditions = "#{reflection.klass.quoted_table_name}.#{connection.quote_column_name "#{interface}_id"} #{in_or_equals_for_ids(ids)} and #{reflection.klass.quoted_table_name}.#{connection.quote_column_name "#{interface}_type"} = '#{self.base_class.sti_name}'"
  else
    foreign_key = reflection.cpk_primary_key

    where = (foreign_key * ids.size).in_groups_of(foreign_key.size).map do |keys|
      "(" + keys.map{|key| "#{reflection.klass.quoted_table_name}.#{connection.quote_column_name(key)} = ?"}.join(" AND ") + ")"
    end.join(" OR ")

    conditions = [where, ids].flatten
  end

  conditions[0] << append_conditions(reflection, preload_options)

  find_options = {
    :select => preload_options[:select] || options[:select] || "#{table_name}.*",
    :include => preload_options[:include] || options[:include],
    # CPK
    # :conditions => [conditions, ids],
    :conditions => conditions,
    :joins => options[:joins],
    :group => preload_options[:group] || options[:group],
    :order => preload_options[:order] || options[:order]
  }

  reflection.klass.unscoped.apply_finder_options(find_options).to_a
end

#full_composite_join_clause(reflection, table1, full_keys1, table2, full_keys2) ⇒ Object 



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# File 'lib/composite_primary_keys/association_preload.rb', line 144

def full_composite_join_clause(reflection, table1, full_keys1, table2, full_keys2)
  connection = reflection.active_record.connection
  full_keys1 = full_keys1.split(CompositePrimaryKeys::ID_SEP) if full_keys1.is_a?(String)
  full_keys2 = full_keys2.split(CompositePrimaryKeys::ID_SEP) if full_keys2.is_a?(String)
  where_clause = [full_keys1, full_keys2].transpose.map do |key_pair|
    quoted1 = connection.quote_table_name(table1)
    quoted2 = connection.quote_table_name(table2)
    "#{quoted1}.#{connection.quote_column_name(key_pair.first)}=#{quoted2}.#{connection.quote_column_name(key_pair.last)}"
  end.join(" AND ")
  "(#{where_clause})"
end

#preload_belongs_to_association(records, reflection, preload_options = {}) ⇒ Object 



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# File 'lib/composite_primary_keys/association_preload.rb', line 44

def preload_belongs_to_association(records, reflection, preload_options={})
  return if records.first.send("loaded_#{reflection.name}?")
  options = reflection.options
  
  ids = Array.new
  
  if options[:polymorphic]
    # CPK
    #polymorph_type = options[:foreign_type]
    #klasses_and_ids = {}

    # Construct a mapping from klass to a list of ids to load and a mapping of those ids back to their parent_records
    #records.each do |record|
    #  if klass = record.send(polymorph_type)
    #    klass_id = record.send(primary_key_name)
    #    if klass_id
    #      id_map = klasses_and_ids[klass] ||= {}
    #      id_list_for_klass_id = (id_map[klass_id.to_s] ||= [])
    #      id_list_for_klass_id << record
    #    end
    #  end
    #end
    #klasses_and_ids = klasses_and_ids.to_a
    raise AssociationNotSupported, "Polymorphic joins not supported for composite keys"
  else
    # I need to keep the original ids for each record (as opposed to the stringified) so
    # that they get properly converted for each db so the id_map ends up looking like:
    #
    # { '1,2' => {:id => [1,2], :records => [...records...]}}
    id_map = {}

    records.each do |record|
      keys = record[reflection.cpk_primary_key]
      ids << keys

      mapped_records = (id_map[keys.to_s] ||= [])
      mapped_records << record
    end

    klasses_and_ids = [[reflection.klass.name, id_map]]
  end

  klasses_and_ids.each do |klass_and_id|
    klass_name, id_map = *klass_and_id
    next if id_map.empty?
    klass = klass_name.constantize

    table_name = klass.quoted_table_name
    primary_key = [reflection.options[:primary_key] || klass.primary_key].flatten

    # CPK
    conditions = id_map.map do |key, value|
      "(" +
      primary_key.map do |key|
        "#{table_name}.#{connection.quote_column_name(key)} = ?"
      end.join(' AND ') + ")"
    end.join(' OR ')

    conditions << append_conditions(reflection, preload_options)

    conditions = [conditions] + ids.uniq.flatten

    associated_records = klass.unscoped.where(conditions).apply_finder_options(options.slice(:include, :select, :joins, :order)).to_a

    set_association_single_records(id_map, reflection.name, associated_records, primary_key)
  end
end

#preload_has_and_belongs_to_many_association(records, reflection, preload_options = {}) ⇒ Object 



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# File 'lib/composite_primary_keys/association_preload.rb', line 11

def preload_has_and_belongs_to_many_association(records, reflection, preload_options={})
  table_name = reflection.klass.quoted_table_name
  id_to_record_map, ids = construct_id_map(records)
  records.each {|record| record.send(reflection.name).loaded}
  options = reflection.options

  if composite?
    where = (primary_key * ids.size).in_groups_of(primary_key.size).map do |keys|
      "(" + keys.map{|key| "t0.#{connection.quote_column_name(key)} = ?"}.join(" AND ") + ")"
    end.join(" OR ")

    conditions = [where, ids].flatten
    joins = "INNER JOIN #{connection.quote_table_name options[:join_table]} t0 ON #{full_composite_join_clause(reflection, reflection.klass.table_name, reflection.klass.primary_key, 't0', reflection.association_foreign_key)}"
    parent_primary_keys = reflection.cpk_primary_key.map{|k| "t0.#{connection.quote_column_name(k)}"}
    concat_arr = parent_primary_keys.zip(["'#{CompositePrimaryKeys::ID_SEP}'"] * (parent_primary_keys.size - 1)).flatten.compact
    parent_record_id = connection.concat(*concat_arr)
  else
    conditions = "t0.#{reflection.primary_key_name} #{in_or_equals_for_ids(ids)}"
    conditions << append_conditions(reflection, preload_options)
    conditions = [conditions, ids]
    joins = "INNER JOIN #{connection.quote_table_name options[:join_table]} t0 ON #{reflection.klass.quoted_table_name}.#{reflection.klass.primary_key} = t0.#{reflection.association_foreign_key}"
    parent_record_id = reflection.primary_key_name
 end

associated_records = reflection.klass.unscoped.where(conditions).
    includes(options[:include]).
    joins(joins).
    select("#{options[:select] || table_name+'.*'}, #{parent_record_id} as the_parent_record_id").
    order(options[:order]).to_a

  set_association_collection_records(id_to_record_map, reflection.name, associated_records, 'the_parent_record_id')
end