Class: ActiveRecord::Associations::JoinDependency
- Inherits:
-
Object
- Object
- ActiveRecord::Associations::JoinDependency
- Defined in:
- lib/active_record/associations/join_dependency.rb,
lib/active_record/associations/join_dependency/join_base.rb,
lib/active_record/associations/join_dependency/join_part.rb,
lib/active_record/associations/join_dependency/join_association.rb
Overview
:nodoc:
Defined Under Namespace
Classes: Aliases, JoinAssociation, JoinBase, JoinPart
Instance Attribute Summary collapse
-
#alias_tracker ⇒ Object
readonly
Returns the value of attribute alias_tracker.
-
#base_klass ⇒ Object
readonly
Returns the value of attribute base_klass.
-
#join_root ⇒ Object
readonly
Returns the value of attribute join_root.
Class Method Summary collapse
Instance Method Summary collapse
- #aliases ⇒ Object
-
#initialize(base, associations, joins, eager_loading: true) ⇒ JoinDependency
constructor
base is the base class on which operation is taking place.
- #instantiate(result_set, aliases) ⇒ Object
- #join_constraints(outer_joins, join_type) ⇒ Object
- #reflections ⇒ Object
Constructor Details
#initialize(base, associations, joins, eager_loading: true) ⇒ JoinDependency
base is the base class on which operation is taking place. associations is the list of associations which are joined using hash, symbol or array. joins is the list of all string join commands and arel nodes.
Example :
class Physician < ActiveRecord::Base
has_many :appointments
has_many :patients, through: :appointments
end
If I execute `@physician.patients.to_a` then
base # => Physician
associations # => []
joins # => [#<Arel::Nodes::InnerJoin: ...]
However if I execute `Physician.joins(:appointments).to_a` then
base # => Physician
associations # => [:appointments]
joins # => []
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# File 'lib/active_record/associations/join_dependency.rb', line 95 def initialize(base, associations, joins, eager_loading: true) @alias_tracker = AliasTracker.create_with_joins(base.connection, base.table_name, joins, base.type_caster) @eager_loading = eager_loading tree = self.class.make_tree associations @join_root = JoinBase.new base, build(tree, base) @join_root.children.each { |child| construct_tables! @join_root, child } end |
Instance Attribute Details
#alias_tracker ⇒ Object (readonly)
Returns the value of attribute alias_tracker.
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# File 'lib/active_record/associations/join_dependency.rb', line 48 def alias_tracker @alias_tracker end |
#base_klass ⇒ Object (readonly)
Returns the value of attribute base_klass.
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# File 'lib/active_record/associations/join_dependency.rb', line 48 def base_klass @base_klass end |
#join_root ⇒ Object (readonly)
Returns the value of attribute join_root.
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# File 'lib/active_record/associations/join_dependency.rb', line 48 def join_root @join_root end |
Class Method Details
.make_tree(associations) ⇒ Object
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# File 'lib/active_record/associations/join_dependency.rb', line 50 def self.make_tree(associations) hash = {} walk_tree associations, hash hash end |
.walk_tree(associations, hash) ⇒ Object
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# File 'lib/active_record/associations/join_dependency.rb', line 56 def self.walk_tree(associations, hash) case associations when Symbol, String hash[associations.to_sym] ||= {} when Array associations.each do |assoc| walk_tree assoc, hash end when Hash associations.each do |k, v| cache = hash[k] ||= {} walk_tree v, cache end else raise ConfigurationError, associations.inspect end end |
Instance Method Details
#aliases ⇒ Object
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# File 'lib/active_record/associations/join_dependency.rb', line 128 def aliases Aliases.new join_root.each_with_index.map { |join_part, i| columns = join_part.column_names.each_with_index.map { |column_name, j| Aliases::Column.new column_name, "t#{i}_r#{j}" } Aliases::Table.new(join_part, columns) } end |
#instantiate(result_set, aliases) ⇒ Object
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# File 'lib/active_record/associations/join_dependency.rb', line 137 def instantiate(result_set, aliases) primary_key = aliases.column_alias(join_root, join_root.primary_key) seen = Hash.new { |i, object_id| i[object_id] = Hash.new { |j, child_class| j[child_class] = {} } } model_cache = Hash.new { |h, klass| h[klass] = {} } parents = model_cache[join_root] column_aliases = aliases.column_aliases join_root = ActiveSupport::Notifications.instrumenter payload = { record_count: result_set.length, class_name: join_root.base_klass.name } .instrument("instantiation.active_record", payload) do result_set.each { |row_hash| parent_key = primary_key ? row_hash[primary_key] : row_hash parent = parents[parent_key] ||= join_root.instantiate(row_hash, column_aliases) construct(parent, join_root, row_hash, result_set, seen, model_cache, aliases) } end parents.values end |
#join_constraints(outer_joins, join_type) ⇒ Object
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# File 'lib/active_record/associations/join_dependency.rb', line 107 def join_constraints(outer_joins, join_type) joins = join_root.children.flat_map { |child| if join_type == Arel::Nodes::OuterJoin make_left_outer_joins join_root, child else make_inner_joins join_root, child end } joins.concat outer_joins.flat_map { |oj| if join_root.match? oj.join_root walk join_root, oj.join_root else oj.join_root.children.flat_map { |child| make_outer_joins oj.join_root, child } end } end |
#reflections ⇒ Object
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# File 'lib/active_record/associations/join_dependency.rb', line 103 def reflections join_root.drop(1).map!(&:reflection) end |