aboutsummaryrefslogtreecommitdiffstats
path: root/activerecord/lib/active_record/associations/class_methods/join_dependency.rb
blob: 19d2d55ca05ef3837ecc25612df1aad2bd395d5c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
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 columns
          join_parts.collect { |join_part|
            table = join_part.aliased_table
            join_part.column_names_with_alias.collect{ |column_name, aliased_name|
              table[column_name].as aliased_name
            }
          }.flatten
        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