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breaking classes up in to respective files

This commit is contained in:
Aaron Patterson 2010-11-23 17:34:18 -08:00
parent a551d2ec62
commit 1aaa8edeb9
5 changed files with 605 additions and 574 deletions

View file

@ -5,6 +5,7 @@ require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/string/conversions'
require 'active_support/core_ext/module/remove_method'
require 'active_support/core_ext/class/attribute'
require 'active_record/associations/class_methods/join_dependency'
module ActiveRecord
class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc:
@ -1832,580 +1833,6 @@ module ActiveRecord
Array.wrap(extensions)
end
end
class JoinDependency # :nodoc:
attr_reader :join_parts, :reflections, :table_aliases
def initialize(base, associations, joins)
@join_parts = [JoinBase.new(base, joins)]
@associations = {}
@reflections = []
@table_aliases = Hash.new(0)
@table_aliases[base.table_name] = 1
build(associations)
end
def graft(*associations)
associations.each do |association|
join_associations.detect {|a| association == a} ||
build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type)
end
self
end
def join_associations
join_parts.last(join_parts.length - 1)
end
def join_base
join_parts.first
end
def count_aliases_from_table_joins(name)
# quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase
quoted_name = join_base.active_record.connection.quote_table_name(name.downcase).downcase
join_sql = join_base.table_joins.to_s.downcase
join_sql.blank? ? 0 :
# Table names
join_sql.scan(/join(?:\s+\w+)?\s+#{quoted_name}\son/).size +
# Table aliases
join_sql.scan(/join(?:\s+\w+)?\s+\S+\s+#{quoted_name}\son/).size
end
def instantiate(rows)
primary_key = join_base.aliased_primary_key
parents = {}
records = rows.map { |model|
primary_id = model[primary_key]
parent = parents[primary_id] ||= join_base.instantiate(model)
construct(parent, @associations, join_associations.dup, model)
parent
}.uniq
remove_duplicate_results!(join_base.active_record, records, @associations)
records
end
def remove_duplicate_results!(base, records, associations)
case associations
when Symbol, String
reflection = base.reflections[associations]
remove_uniq_by_reflection(reflection, records)
when Array
associations.each do |association|
remove_duplicate_results!(base, records, association)
end
when Hash
associations.keys.each do |name|
reflection = base.reflections[name]
remove_uniq_by_reflection(reflection, records)
parent_records = []
records.each do |record|
if descendant = record.send(reflection.name)
if reflection.collection?
parent_records.concat descendant.target.uniq
else
parent_records << descendant
end
end
end
remove_duplicate_results!(reflection.klass, parent_records, associations[name]) unless parent_records.empty?
end
end
end
protected
def cache_joined_association(association)
associations = []
parent = association.parent
while parent != join_base
associations.unshift(parent.reflection.name)
parent = parent.parent
end
ref = @associations
associations.each do |key|
ref = ref[key]
end
ref[association.reflection.name] ||= {}
end
def build(associations, parent = nil, join_type = Arel::InnerJoin)
parent ||= join_parts.last
case associations
when Symbol, String
reflection = parent.reflections[associations.to_s.intern] or
raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?"
unless join_association = find_join_association(reflection, parent)
@reflections << reflection
join_association = build_join_association(reflection, parent)
join_association.join_type = join_type
@join_parts << join_association
cache_joined_association(join_association)
end
join_association
when Array
associations.each do |association|
build(association, parent, join_type)
end
when Hash
associations.keys.sort{|a,b|a.to_s<=>b.to_s}.each do |name|
join_association = build(name, parent, join_type)
build(associations[name], join_association, join_type)
end
else
raise ConfigurationError, associations.inspect
end
end
def find_join_association(name_or_reflection, parent)
if String === name_or_reflection
name_or_reflection = name_or_reflection.to_sym
end
join_associations.detect { |j|
j.reflection == name_or_reflection && j.parent == parent
}
end
def remove_uniq_by_reflection(reflection, records)
if reflection && reflection.collection?
records.each { |record| record.send(reflection.name).target.uniq! }
end
end
def build_join_association(reflection, parent)
JoinAssociation.new(reflection, self, parent)
end
def construct(parent, associations, join_parts, row)
case associations
when Symbol, String
name = associations.to_s
join_part = join_parts.detect { |j|
j.reflection.name.to_s == name &&
j.parent_table_name == parent.class.table_name }
raise(ConfigurationError, "No such association") unless join_part
join_parts.delete(join_part)
construct_association(parent, join_part, row)
when Array
associations.each do |association|
construct(parent, association, join_parts, row)
end
when Hash
associations.sort_by { |k,_| k.to_s }.each do |name, assoc|
association = construct(parent, name, join_parts, row)
construct(association, assoc, join_parts, row) if association
end
else
raise ConfigurationError, associations.inspect
end
end
def construct_association(record, join_part, row)
return if record.id.to_s != join_part.parent.record_id(row).to_s
macro = join_part.reflection.macro
if macro == :has_one
return if record.instance_variable_defined?("@#{join_part.reflection.name}")
association = join_part.instantiate(row) unless row[join_part.aliased_primary_key].nil?
set_target_and_inverse(join_part, association, record)
else
return if row[join_part.aliased_primary_key].nil?
association = join_part.instantiate(row)
case macro
when :has_many, :has_and_belongs_to_many
collection = record.send(join_part.reflection.name)
collection.loaded
collection.target.push(association)
collection.__send__(:set_inverse_instance, association, record)
when :belongs_to
set_target_and_inverse(join_part, association, record)
else
raise ConfigurationError, "unknown macro: #{join_part.reflection.macro}"
end
end
association
end
def set_target_and_inverse(join_part, association, record)
association_proxy = record.send("set_#{join_part.reflection.name}_target", association)
association_proxy.__send__(:set_inverse_instance, association, record)
end
# A JoinPart represents a part of a JoinDependency. It is an abstract class, inherited
# by JoinBase and JoinAssociation. A JoinBase represents the Active Record which
# everything else is being joined onto. A JoinAssociation represents an association which
# is joining to the base. A JoinAssociation may result in more than one actual join
# operations (for example a has_and_belongs_to_many JoinAssociation would result in
# two; one for the join table and one for the target table).
class JoinPart # :nodoc:
# The Active Record class which this join part is associated 'about'; for a JoinBase
# this is the actual base model, for a JoinAssociation this is the target model of the
# association.
attr_reader :active_record
delegate :table_name, :column_names, :primary_key, :reflections, :sanitize_sql, :arel_engine, :to => :active_record
def initialize(active_record)
@active_record = active_record
@cached_record = {}
end
def ==(other)
raise NotImplementedError
end
# An Arel::Table for the active_record
def table
raise NotImplementedError
end
# The prefix to be used when aliasing columns in the active_record's table
def aliased_prefix
raise NotImplementedError
end
# The alias for the active_record's table
def aliased_table_name
raise NotImplementedError
end
# The alias for the primary key of the active_record's table
def aliased_primary_key
"#{aliased_prefix}_r0"
end
# An array of [column_name, alias] pairs for the table
def column_names_with_alias
unless defined?(@column_names_with_alias)
@column_names_with_alias = []
([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i|
@column_names_with_alias << [column_name, "#{aliased_prefix}_r#{i}"]
end
end
@column_names_with_alias
end
def extract_record(row)
Hash[column_names_with_alias.map{|cn, an| [cn, row[an]]}]
end
def record_id(row)
row[aliased_primary_key]
end
def instantiate(row)
@cached_record[record_id(row)] ||= active_record.send(:instantiate, extract_record(row))
end
end
class JoinBase < JoinPart # :nodoc:
# Extra joins provided when the JoinDependency was created
attr_reader :table_joins
def initialize(active_record, joins = nil)
super(active_record)
@table_joins = joins
end
def ==(other)
other.class == self.class &&
other.active_record == active_record
end
def aliased_prefix
"t0"
end
def table
Arel::Table.new(table_name, :engine => arel_engine, :columns => active_record.columns)
end
def aliased_table_name
active_record.table_name
end
end
class JoinAssociation < JoinPart # :nodoc:
# The reflection of the association represented
attr_reader :reflection
# The JoinDependency object which this JoinAssociation exists within. This is mainly
# relevant for generating aliases which do not conflict with other joins which are
# part of the query.
attr_reader :join_dependency
# A JoinBase instance representing the active record we are joining onto.
# (So in Author.has_many :posts, the Author would be that base record.)
attr_reader :parent
# What type of join will be generated, either Arel::InnerJoin (default) or Arel::OuterJoin
attr_accessor :join_type
# These implement abstract methods from the superclass
attr_reader :aliased_prefix, :aliased_table_name
delegate :options, :through_reflection, :source_reflection, :to => :reflection
delegate :table, :table_name, :to => :parent, :prefix => true
def initialize(reflection, join_dependency, parent = nil)
reflection.check_validity!
if reflection.options[:polymorphic]
raise EagerLoadPolymorphicError.new(reflection)
end
super(reflection.klass)
@reflection = reflection
@join_dependency = join_dependency
@parent = parent
@join_type = Arel::InnerJoin
# This must be done eagerly upon initialisation because the alias which is produced
# depends on the state of the join dependency, but we want it to work the same way
# every time.
allocate_aliases
end
def ==(other)
other.class == self.class &&
other.reflection == reflection &&
other.parent == parent
end
def find_parent_in(other_join_dependency)
other_join_dependency.join_parts.detect do |join_part|
self.parent == join_part
end
end
def join_to(relation)
send("join_#{reflection.macro}_to", relation)
end
def join_relation(joining_relation)
self.join_type = Arel::OuterJoin
joining_relation.joins(self)
end
def table
@table ||= Arel::Table.new(
table_name, :as => aliased_table_name,
:engine => arel_engine, :columns => active_record.columns
)
end
# More semantic name given we are talking about associations
alias_method :target_table, :table
protected
def aliased_table_name_for(name, suffix = nil)
if @join_dependency.table_aliases[name].zero?
@join_dependency.table_aliases[name] = @join_dependency.count_aliases_from_table_joins(name)
end
if !@join_dependency.table_aliases[name].zero? # We need an alias
name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}"
@join_dependency.table_aliases[name] += 1
if @join_dependency.table_aliases[name] == 1 # First time we've seen this name
# Also need to count the aliases from the table_aliases to avoid incorrect count
@join_dependency.table_aliases[name] += @join_dependency.count_aliases_from_table_joins(name)
end
table_index = @join_dependency.table_aliases[name]
name = name[0..active_record.connection.table_alias_length-3] + "_#{table_index}" if table_index > 1
else
@join_dependency.table_aliases[name] += 1
end
name
end
def pluralize(table_name)
ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name
end
def interpolate_sql(sql)
instance_eval("%@#{sql.gsub('@', '\@')}@", __FILE__, __LINE__)
end
private
def allocate_aliases
@aliased_prefix = "t#{ join_dependency.join_parts.size }"
@aliased_table_name = aliased_table_name_for(table_name)
if reflection.macro == :has_and_belongs_to_many
@aliased_join_table_name = aliased_table_name_for(reflection.options[:join_table], "_join")
elsif [:has_many, :has_one].include?(reflection.macro) && reflection.options[:through]
@aliased_join_table_name = aliased_table_name_for(reflection.through_reflection.klass.table_name, "_join")
end
end
def process_conditions(conditions, table_name)
Arel.sql(interpolate_sql(sanitize_sql(conditions, table_name)))
end
def join_target_table(relation, *conditions)
relation = relation.join(target_table, join_type)
# If the target table is an STI model then we must be sure to only include records of
# its type and its sub-types.
unless active_record.descends_from_active_record?
sti_column = target_table[active_record.inheritance_column]
sti_condition = sti_column.eq(active_record.sti_name)
active_record.descendants.each do |subclass|
sti_condition = sti_condition.or(sti_column.eq(subclass.sti_name))
end
conditions << sti_condition
end
# If the reflection has conditions, add them
if options[:conditions]
conditions << process_conditions(options[:conditions], aliased_table_name)
end
relation = relation.on(*conditions)
end
def join_has_and_belongs_to_many_to(relation)
join_table = Arel::Table.new(
options[:join_table], :engine => arel_engine,
:as => @aliased_join_table_name
)
fk = options[:foreign_key] || reflection.active_record.to_s.foreign_key
klass_fk = options[:association_foreign_key] || reflection.klass.to_s.foreign_key
relation = relation.join(join_table, join_type)
relation = relation.on(
join_table[fk].
eq(parent_table[reflection.active_record.primary_key])
)
join_target_table(
relation,
target_table[reflection.klass.primary_key].
eq(join_table[klass_fk])
)
end
def join_has_many_to(relation)
if reflection.options[:through]
join_has_many_through_to(relation)
elsif reflection.options[:as]
join_has_many_polymorphic_to(relation)
else
foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key
primary_key = options[:primary_key] || parent.primary_key
join_target_table(
relation,
target_table[foreign_key].
eq(parent_table[primary_key])
)
end
end
alias :join_has_one_to :join_has_many_to
def join_has_many_through_to(relation)
join_table = Arel::Table.new(
through_reflection.klass.table_name, :engine => arel_engine,
:as => @aliased_join_table_name
)
jt_conditions = []
jt_foreign_key = first_key = second_key = nil
if through_reflection.options[:as] # has_many :through against a polymorphic join
as_key = through_reflection.options[:as].to_s
jt_foreign_key = as_key + '_id'
jt_conditions <<
join_table[as_key + '_type'].
eq(parent.active_record.base_class.name)
else
jt_foreign_key = through_reflection.primary_key_name
end
case source_reflection.macro
when :has_many
second_key = options[:foreign_key] || primary_key
if source_reflection.options[:as]
first_key = "#{source_reflection.options[:as]}_id"
else
first_key = through_reflection.klass.base_class.to_s.foreign_key
end
unless through_reflection.klass.descends_from_active_record?
jt_conditions <<
join_table[through_reflection.active_record.inheritance_column].
eq(through_reflection.klass.sti_name)
end
when :belongs_to
first_key = primary_key
if reflection.options[:source_type]
second_key = source_reflection.association_foreign_key
jt_conditions <<
join_table[reflection.source_reflection.options[:foreign_type]].
eq(reflection.options[:source_type])
else
second_key = source_reflection.primary_key_name
end
end
jt_conditions <<
parent_table[parent.primary_key].
eq(join_table[jt_foreign_key])
if through_reflection.options[:conditions]
jt_conditions << process_conditions(through_reflection.options[:conditions], aliased_table_name)
end
relation = relation.join(join_table, join_type).on(*jt_conditions)
join_target_table(
relation,
target_table[first_key].eq(join_table[second_key])
)
end
def join_has_many_polymorphic_to(relation)
join_target_table(
relation,
target_table["#{reflection.options[:as]}_id"].
eq(parent_table[parent.primary_key]),
target_table["#{reflection.options[:as]}_type"].
eq(parent.active_record.base_class.name)
)
end
def join_belongs_to_to(relation)
foreign_key = options[:foreign_key] || reflection.primary_key_name
primary_key = options[:primary_key] || reflection.klass.primary_key
join_target_table(
relation,
target_table[primary_key].eq(parent_table[foreign_key])
)
end
end
end
end
end
end

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@ -0,0 +1,216 @@
require 'active_record/associations/class_methods/join_dependency/join_part'
require 'active_record/associations/class_methods/join_dependency/join_base'
require 'active_record/associations/class_methods/join_dependency/join_association'
module ActiveRecord
module Associations
module ClassMethods
class JoinDependency # :nodoc:
attr_reader :join_parts, :reflections, :table_aliases
def initialize(base, associations, joins)
@join_parts = [JoinBase.new(base, joins)]
@associations = {}
@reflections = []
@table_aliases = Hash.new(0)
@table_aliases[base.table_name] = 1
build(associations)
end
def graft(*associations)
associations.each do |association|
join_associations.detect {|a| association == a} ||
build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type)
end
self
end
def join_associations
join_parts.last(join_parts.length - 1)
end
def join_base
join_parts.first
end
def count_aliases_from_table_joins(name)
# quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase
quoted_name = join_base.active_record.connection.quote_table_name(name.downcase).downcase
join_sql = join_base.table_joins.to_s.downcase
join_sql.blank? ? 0 :
# Table names
join_sql.scan(/join(?:\s+\w+)?\s+#{quoted_name}\son/).size +
# Table aliases
join_sql.scan(/join(?:\s+\w+)?\s+\S+\s+#{quoted_name}\son/).size
end
def instantiate(rows)
primary_key = join_base.aliased_primary_key
parents = {}
records = rows.map { |model|
primary_id = model[primary_key]
parent = parents[primary_id] ||= join_base.instantiate(model)
construct(parent, @associations, join_associations.dup, model)
parent
}.uniq
remove_duplicate_results!(join_base.active_record, records, @associations)
records
end
def remove_duplicate_results!(base, records, associations)
case associations
when Symbol, String
reflection = base.reflections[associations]
remove_uniq_by_reflection(reflection, records)
when Array
associations.each do |association|
remove_duplicate_results!(base, records, association)
end
when Hash
associations.keys.each do |name|
reflection = base.reflections[name]
remove_uniq_by_reflection(reflection, records)
parent_records = []
records.each do |record|
if descendant = record.send(reflection.name)
if reflection.collection?
parent_records.concat descendant.target.uniq
else
parent_records << descendant
end
end
end
remove_duplicate_results!(reflection.klass, parent_records, associations[name]) unless parent_records.empty?
end
end
end
protected
def cache_joined_association(association)
associations = []
parent = association.parent
while parent != join_base
associations.unshift(parent.reflection.name)
parent = parent.parent
end
ref = @associations
associations.each do |key|
ref = ref[key]
end
ref[association.reflection.name] ||= {}
end
def build(associations, parent = nil, join_type = Arel::InnerJoin)
parent ||= join_parts.last
case associations
when Symbol, String
reflection = parent.reflections[associations.to_s.intern] or
raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?"
unless join_association = find_join_association(reflection, parent)
@reflections << reflection
join_association = build_join_association(reflection, parent)
join_association.join_type = join_type
@join_parts << join_association
cache_joined_association(join_association)
end
join_association
when Array
associations.each do |association|
build(association, parent, join_type)
end
when Hash
associations.keys.sort{|a,b|a.to_s<=>b.to_s}.each do |name|
join_association = build(name, parent, join_type)
build(associations[name], join_association, join_type)
end
else
raise ConfigurationError, associations.inspect
end
end
def find_join_association(name_or_reflection, parent)
if String === name_or_reflection
name_or_reflection = name_or_reflection.to_sym
end
join_associations.detect { |j|
j.reflection == name_or_reflection && j.parent == parent
}
end
def remove_uniq_by_reflection(reflection, records)
if reflection && reflection.collection?
records.each { |record| record.send(reflection.name).target.uniq! }
end
end
def build_join_association(reflection, parent)
JoinAssociation.new(reflection, self, parent)
end
def construct(parent, associations, join_parts, row)
case associations
when Symbol, String
name = associations.to_s
join_part = join_parts.detect { |j|
j.reflection.name.to_s == name &&
j.parent_table_name == parent.class.table_name }
raise(ConfigurationError, "No such association") unless join_part
join_parts.delete(join_part)
construct_association(parent, join_part, row)
when Array
associations.each do |association|
construct(parent, association, join_parts, row)
end
when Hash
associations.sort_by { |k,_| k.to_s }.each do |name, assoc|
association = construct(parent, name, join_parts, row)
construct(association, assoc, join_parts, row) if association
end
else
raise ConfigurationError, associations.inspect
end
end
def construct_association(record, join_part, row)
return if record.id.to_s != join_part.parent.record_id(row).to_s
macro = join_part.reflection.macro
if macro == :has_one
return if record.instance_variable_defined?("@#{join_part.reflection.name}")
association = join_part.instantiate(row) unless row[join_part.aliased_primary_key].nil?
set_target_and_inverse(join_part, association, record)
else
return if row[join_part.aliased_primary_key].nil?
association = join_part.instantiate(row)
case macro
when :has_many, :has_and_belongs_to_many
collection = record.send(join_part.reflection.name)
collection.loaded
collection.target.push(association)
collection.__send__(:set_inverse_instance, association, record)
when :belongs_to
set_target_and_inverse(join_part, association, record)
else
raise ConfigurationError, "unknown macro: #{join_part.reflection.macro}"
end
end
association
end
def set_target_and_inverse(join_part, association, record)
association_proxy = record.send("set_#{join_part.reflection.name}_target", association)
association_proxy.__send__(:set_inverse_instance, association, record)
end
end
end
end
end

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@ -0,0 +1,278 @@
module ActiveRecord
module Associations
module ClassMethods
class JoinDependency # :nodoc:
class JoinAssociation < JoinPart # :nodoc:
# The reflection of the association represented
attr_reader :reflection
# The JoinDependency object which this JoinAssociation exists within. This is mainly
# relevant for generating aliases which do not conflict with other joins which are
# part of the query.
attr_reader :join_dependency
# A JoinBase instance representing the active record we are joining onto.
# (So in Author.has_many :posts, the Author would be that base record.)
attr_reader :parent
# What type of join will be generated, either Arel::InnerJoin (default) or Arel::OuterJoin
attr_accessor :join_type
# These implement abstract methods from the superclass
attr_reader :aliased_prefix, :aliased_table_name
delegate :options, :through_reflection, :source_reflection, :to => :reflection
delegate :table, :table_name, :to => :parent, :prefix => true
def initialize(reflection, join_dependency, parent = nil)
reflection.check_validity!
if reflection.options[:polymorphic]
raise EagerLoadPolymorphicError.new(reflection)
end
super(reflection.klass)
@reflection = reflection
@join_dependency = join_dependency
@parent = parent
@join_type = Arel::InnerJoin
# This must be done eagerly upon initialisation because the alias which is produced
# depends on the state of the join dependency, but we want it to work the same way
# every time.
allocate_aliases
end
def ==(other)
other.class == self.class &&
other.reflection == reflection &&
other.parent == parent
end
def find_parent_in(other_join_dependency)
other_join_dependency.join_parts.detect do |join_part|
self.parent == join_part
end
end
def join_to(relation)
send("join_#{reflection.macro}_to", relation)
end
def join_relation(joining_relation)
self.join_type = Arel::OuterJoin
joining_relation.joins(self)
end
def table
@table ||= Arel::Table.new(
table_name, :as => aliased_table_name,
:engine => arel_engine, :columns => active_record.columns
)
end
# More semantic name given we are talking about associations
alias_method :target_table, :table
protected
def aliased_table_name_for(name, suffix = nil)
if @join_dependency.table_aliases[name].zero?
@join_dependency.table_aliases[name] = @join_dependency.count_aliases_from_table_joins(name)
end
if !@join_dependency.table_aliases[name].zero? # We need an alias
name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}"
@join_dependency.table_aliases[name] += 1
if @join_dependency.table_aliases[name] == 1 # First time we've seen this name
# Also need to count the aliases from the table_aliases to avoid incorrect count
@join_dependency.table_aliases[name] += @join_dependency.count_aliases_from_table_joins(name)
end
table_index = @join_dependency.table_aliases[name]
name = name[0..active_record.connection.table_alias_length-3] + "_#{table_index}" if table_index > 1
else
@join_dependency.table_aliases[name] += 1
end
name
end
def pluralize(table_name)
ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name
end
def interpolate_sql(sql)
instance_eval("%@#{sql.gsub('@', '\@')}@", __FILE__, __LINE__)
end
private
def allocate_aliases
@aliased_prefix = "t#{ join_dependency.join_parts.size }"
@aliased_table_name = aliased_table_name_for(table_name)
if reflection.macro == :has_and_belongs_to_many
@aliased_join_table_name = aliased_table_name_for(reflection.options[:join_table], "_join")
elsif [:has_many, :has_one].include?(reflection.macro) && reflection.options[:through]
@aliased_join_table_name = aliased_table_name_for(reflection.through_reflection.klass.table_name, "_join")
end
end
def process_conditions(conditions, table_name)
Arel.sql(interpolate_sql(sanitize_sql(conditions, table_name)))
end
def join_target_table(relation, *conditions)
relation = relation.join(target_table, join_type)
# If the target table is an STI model then we must be sure to only include records of
# its type and its sub-types.
unless active_record.descends_from_active_record?
sti_column = target_table[active_record.inheritance_column]
sti_condition = sti_column.eq(active_record.sti_name)
active_record.descendants.each do |subclass|
sti_condition = sti_condition.or(sti_column.eq(subclass.sti_name))
end
conditions << sti_condition
end
# If the reflection has conditions, add them
if options[:conditions]
conditions << process_conditions(options[:conditions], aliased_table_name)
end
relation = relation.on(*conditions)
end
def join_has_and_belongs_to_many_to(relation)
join_table = Arel::Table.new(
options[:join_table], :engine => arel_engine,
:as => @aliased_join_table_name
)
fk = options[:foreign_key] || reflection.active_record.to_s.foreign_key
klass_fk = options[:association_foreign_key] || reflection.klass.to_s.foreign_key
relation = relation.join(join_table, join_type)
relation = relation.on(
join_table[fk].
eq(parent_table[reflection.active_record.primary_key])
)
join_target_table(
relation,
target_table[reflection.klass.primary_key].
eq(join_table[klass_fk])
)
end
def join_has_many_to(relation)
if reflection.options[:through]
join_has_many_through_to(relation)
elsif reflection.options[:as]
join_has_many_polymorphic_to(relation)
else
foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key
primary_key = options[:primary_key] || parent.primary_key
join_target_table(
relation,
target_table[foreign_key].
eq(parent_table[primary_key])
)
end
end
alias :join_has_one_to :join_has_many_to
def join_has_many_through_to(relation)
join_table = Arel::Table.new(
through_reflection.klass.table_name, :engine => arel_engine,
:as => @aliased_join_table_name
)
jt_conditions = []
jt_foreign_key = first_key = second_key = nil
if through_reflection.options[:as] # has_many :through against a polymorphic join
as_key = through_reflection.options[:as].to_s
jt_foreign_key = as_key + '_id'
jt_conditions <<
join_table[as_key + '_type'].
eq(parent.active_record.base_class.name)
else
jt_foreign_key = through_reflection.primary_key_name
end
case source_reflection.macro
when :has_many
second_key = options[:foreign_key] || primary_key
if source_reflection.options[:as]
first_key = "#{source_reflection.options[:as]}_id"
else
first_key = through_reflection.klass.base_class.to_s.foreign_key
end
unless through_reflection.klass.descends_from_active_record?
jt_conditions <<
join_table[through_reflection.active_record.inheritance_column].
eq(through_reflection.klass.sti_name)
end
when :belongs_to
first_key = primary_key
if reflection.options[:source_type]
second_key = source_reflection.association_foreign_key
jt_conditions <<
join_table[reflection.source_reflection.options[:foreign_type]].
eq(reflection.options[:source_type])
else
second_key = source_reflection.primary_key_name
end
end
jt_conditions <<
parent_table[parent.primary_key].
eq(join_table[jt_foreign_key])
if through_reflection.options[:conditions]
jt_conditions << process_conditions(through_reflection.options[:conditions], aliased_table_name)
end
relation = relation.join(join_table, join_type).on(*jt_conditions)
join_target_table(
relation,
target_table[first_key].eq(join_table[second_key])
)
end
def join_has_many_polymorphic_to(relation)
join_target_table(
relation,
target_table["#{reflection.options[:as]}_id"].
eq(parent_table[parent.primary_key]),
target_table["#{reflection.options[:as]}_type"].
eq(parent.active_record.base_class.name)
)
end
def join_belongs_to_to(relation)
foreign_key = options[:foreign_key] || reflection.primary_key_name
primary_key = options[:primary_key] || reflection.klass.primary_key
join_target_table(
relation,
target_table[primary_key].eq(parent_table[foreign_key])
)
end
end
end
end
end
end

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module ActiveRecord
module Associations
module ClassMethods
class JoinDependency # :nodoc:
class JoinBase < JoinPart # :nodoc:
# Extra joins provided when the JoinDependency was created
attr_reader :table_joins
def initialize(active_record, joins = nil)
super(active_record)
@table_joins = joins
end
def ==(other)
other.class == self.class &&
other.active_record == active_record
end
def aliased_prefix
"t0"
end
def table
Arel::Table.new(table_name, :engine => arel_engine, :columns => active_record.columns)
end
def aliased_table_name
active_record.table_name
end
end
end
end
end
end

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module ActiveRecord
module Associations
module ClassMethods
class JoinDependency # :nodoc:
# A JoinPart represents a part of a JoinDependency. It is an abstract class, inherited
# by JoinBase and JoinAssociation. A JoinBase represents the Active Record which
# everything else is being joined onto. A JoinAssociation represents an association which
# is joining to the base. A JoinAssociation may result in more than one actual join
# operations (for example a has_and_belongs_to_many JoinAssociation would result in
# two; one for the join table and one for the target table).
class JoinPart # :nodoc:
# The Active Record class which this join part is associated 'about'; for a JoinBase
# this is the actual base model, for a JoinAssociation this is the target model of the
# association.
attr_reader :active_record
delegate :table_name, :column_names, :primary_key, :reflections, :sanitize_sql, :arel_engine, :to => :active_record
def initialize(active_record)
@active_record = active_record
@cached_record = {}
end
def ==(other)
raise NotImplementedError
end
# An Arel::Table for the active_record
def table
raise NotImplementedError
end
# The prefix to be used when aliasing columns in the active_record's table
def aliased_prefix
raise NotImplementedError
end
# The alias for the active_record's table
def aliased_table_name
raise NotImplementedError
end
# The alias for the primary key of the active_record's table
def aliased_primary_key
"#{aliased_prefix}_r0"
end
# An array of [column_name, alias] pairs for the table
def column_names_with_alias
unless defined?(@column_names_with_alias)
@column_names_with_alias = []
([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i|
@column_names_with_alias << [column_name, "#{aliased_prefix}_r#{i}"]
end
end
@column_names_with_alias
end
def extract_record(row)
Hash[column_names_with_alias.map{|cn, an| [cn, row[an]]}]
end
def record_id(row)
row[aliased_primary_key]
end
def instantiate(row)
@cached_record[record_id(row)] ||= active_record.send(:instantiate, extract_record(row))
end
end
end
end
end
end