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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
|
module ActiveRecord
module Associations
# Association proxies in Active Record are middlemen between the object that
# holds the association, known as the <tt>@owner</tt>, and the actual associated
# object, known as the <tt>@target</tt>. The kind of association any proxy is
# about is available in <tt>@reflection</tt>. That's an instance of the class
# ActiveRecord::Reflection::AssociationReflection.
#
# For example, given
#
# class Blog < ActiveRecord::Base
# has_many :posts
# end
#
# blog = Blog.first
#
# the association proxy in <tt>blog.posts</tt> has the object in +blog+ as
# <tt>@owner</tt>, the collection of its posts as <tt>@target</tt>, and
# the <tt>@reflection</tt> object represents a <tt>:has_many</tt> macro.
#
# This class delegates unknown methods to <tt>@target</tt> via
# <tt>method_missing</tt>.
#
# The <tt>@target</tt> object is not \loaded until needed. For example,
#
# blog.posts.count
#
# is computed directly through SQL and does not trigger by itself the
# instantiation of the actual post records.
class CollectionProxy < Relation
delegate(*(ActiveRecord::Calculations.public_instance_methods - [:count]), to: :scope)
def initialize(klass, association) #:nodoc:
@association = association
super klass, klass.arel_table
self.default_scoped = true
merge! association.scope(nullify: false)
end
def target
@association.target
end
def load_target
@association.load_target
end
# Returns +true+ if the association has been loaded, otherwise +false+.
#
# person.pets.loaded? # => false
# person.pets
# person.pets.loaded? # => true
def loaded?
@association.loaded?
end
# Works in two ways.
#
# *First:* Specify a subset of fields to be selected from the result set.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.select(:name)
# # => [
# # #<Pet id: nil, name: "Fancy-Fancy">,
# # #<Pet id: nil, name: "Spook">,
# # #<Pet id: nil, name: "Choo-Choo">
# # ]
#
# person.pets.select([:id, :name])
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy">,
# # #<Pet id: 2, name: "Spook">,
# # #<Pet id: 3, name: "Choo-Choo">
# # ]
#
# Be careful because this also means you're initializing a model
# object with only the fields that you've selected. If you attempt
# to access a field that is not in the initialized record you'll
# receive:
#
# person.pets.select(:name).first.person_id
# # => ActiveModel::MissingAttributeError: missing attribute: person_id
#
# *Second:* You can pass a block so it can be used just like Array#select.
# This build an array of objects from the database for the scope,
# converting them into an array and iterating through them using
# Array#select.
#
# person.pets.select { |pet| pet.name =~ /oo/ }
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.select(:name) { |pet| pet.name =~ /oo/ }
# # => [
# # #<Pet id: 2, name: "Spook">,
# # #<Pet id: 3, name: "Choo-Choo">
# # ]
def select(select = nil, &block)
@association.select(select, &block)
end
# Finds an object in the collection responding to the +id+. Uses the same
# rules as <tt>ActiveRecord::Base.find</tt>. Returns <tt>ActiveRecord::RecordNotFound</tt>
# error if the object can not be found.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.find(1) # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>
# person.pets.find(4) # => ActiveRecord::RecordNotFound: Couldn't find Pet with id=4
#
# person.pets.find(2) { |pet| pet.name.downcase! }
# # => #<Pet id: 2, name: "fancy-fancy", person_id: 1>
#
# person.pets.find(2, 3)
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
def find(*args, &block)
@association.find(*args, &block)
end
# Returns the first record, or the first +n+ records, from the collection.
# If the collection is empty, the first form returns +nil+, and the second
# form returns an empty array.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.first # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>
#
# person.pets.first(2)
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>
# # ]
#
# another_person_without.pets # => []
# another_person_without.pets.first # => nil
# another_person_without.pets.first(3) # => []
def first(*args)
@association.first(*args)
end
# Returns the last record, or the last +n+ records, from the collection.
# If the collection is empty, the first form returns +nil+, and the second
# form returns an empty array.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.last # => #<Pet id: 3, name: "Choo-Choo", person_id: 1>
#
# person.pets.last(2)
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# another_person_without.pets # => []
# another_person_without.pets.last # => nil
# another_person_without.pets.last(3) # => []
def last(*args)
@association.last(*args)
end
# Returns a new object of the collection type that has been instantiated
# with +attributes+ and linked to this object, but have not yet been saved.
# You can pass an array of attributes hashes, this will return an array
# with the new objects.
#
# class Person
# has_many :pets
# end
#
# person.pets.build
# # => #<Pet id: nil, name: nil, person_id: 1>
#
# person.pets.build(name: 'Fancy-Fancy')
# # => #<Pet id: nil, name: "Fancy-Fancy", person_id: 1>
#
# person.pets.build([{name: 'Spook'}, {name: 'Choo-Choo'}, {name: 'Brain'}])
# # => [
# # #<Pet id: nil, name: "Spook", person_id: 1>,
# # #<Pet id: nil, name: "Choo-Choo", person_id: 1>,
# # #<Pet id: nil, name: "Brain", person_id: 1>
# # ]
#
# person.pets.size # => 5 # size of the collection
# person.pets.count # => 0 # count from database
def build(attributes = {}, &block)
@association.build(attributes, &block)
end
alias_method :new, :build
# Returns a new object of the collection type that has been instantiated with
# attributes, linked to this object and that has already been saved (if it
# passes the validations).
#
# class Person
# has_many :pets
# end
#
# person.pets.create(name: 'Fancy-Fancy')
# # => #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>
#
# person.pets.create([{name: 'Spook'}, {name: 'Choo-Choo'}])
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.size # => 3
# person.pets.count # => 3
#
# person.pets.find(1, 2, 3)
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
def create(attributes = {}, &block)
@association.create(attributes, &block)
end
# Like +create+, except that if the record is invalid, raises an exception.
#
# class Person
# has_many :pets
# end
#
# class Pet
# validates :name, presence: true
# end
#
# person.pets.create!(name: nil)
# # => ActiveRecord::RecordInvalid: Validation failed: Name can't be blank
def create!(attributes = {}, &block)
@association.create!(attributes, &block)
end
# Add one or more records to the collection by setting their foreign keys
# to the association's primary key. Since << flattens its argument list and
# inserts each record, +push+ and +concat+ behave identically. Returns +self+
# so method calls may be chained.
#
# class Person < ActiveRecord::Base
# pets :has_many
# end
#
# person.pets.size # => 0
# person.pets.concat(Pet.new(name: 'Fancy-Fancy'))
# person.pets.concat(Pet.new(name: 'Spook'), Pet.new(name: 'Choo-Choo'))
# person.pets.size # => 3
#
# person.id # => 1
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.concat([Pet.new(name: 'Brain'), Pet.new(name: 'Benny')])
# person.pets.size # => 5
def concat(*records)
@association.concat(*records)
end
# Replace this collection with +other_array+. This will perform a diff
# and delete/add only records that have changed.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets
# # => [#<Pet id: 1, name: "Gorby", group: "cats", person_id: 1>]
#
# other_pets = [Pet.new(name: 'Puff', group: 'celebrities']
#
# person.pets.replace(other_pets)
#
# person.pets
# # => [#<Pet id: 2, name: "Puff", group: "celebrities", person_id: 1>]
#
# If the supplied array has an incorrect association type, it raises
# an <tt>ActiveRecord::AssociationTypeMismatch</tt> error:
#
# person.pets.replace(["doo", "ggie", "gaga"])
# # => ActiveRecord::AssociationTypeMismatch: Pet expected, got String
def replace(other_array)
@association.replace(other_array)
end
# Deletes all the records from the collection. For +has_many+ associations,
# the deletion is done according to the strategy specified by the <tt>:dependent</tt>
# option. Returns an array with the deleted records.
#
# If no <tt>:dependent</tt> option is given, then it will follow the
# default strategy. The default strategy is <tt>:nullify</tt>. This
# sets the foreign keys to <tt>NULL</tt>. For, +has_many+ <tt>:through</tt>,
# the default strategy is +delete_all+.
#
# class Person < ActiveRecord::Base
# has_many :pets # dependent: :nullify option by default
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.delete_all
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.size # => 0
# person.pets # => []
#
# Pet.find(1, 2, 3)
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: nil>,
# # #<Pet id: 2, name: "Spook", person_id: nil>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: nil>
# # ]
#
# If it is set to <tt>:destroy</tt> all the objects from the collection
# are removed by calling their +destroy+ method. See +destroy+ for more
# information.
#
# class Person < ActiveRecord::Base
# has_many :pets, dependent: :destroy
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.delete_all
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# Pet.find(1, 2, 3)
# # => ActiveRecord::RecordNotFound
#
# If it is set to <tt>:delete_all</tt>, all the objects are deleted
# *without* calling their +destroy+ method.
#
# class Person < ActiveRecord::Base
# has_many :pets, dependent: :delete_all
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.delete_all
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# Pet.find(1, 2, 3)
# # => ActiveRecord::RecordNotFound
def delete_all
@association.delete_all
end
# Deletes the records of the collection directly from the database.
# This will _always_ remove the records ignoring the +:dependent+
# option.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.destroy_all
#
# person.pets.size # => 0
# person.pets # => []
#
# Pet.find(1) # => Couldn't find Pet with id=1
def destroy_all
@association.destroy_all
end
# Deletes the +records+ supplied and removes them from the collection. For
# +has_many+ associations, the deletion is done according to the strategy
# specified by the <tt>:dependent</tt> option. Returns an array with the
# deleted records.
#
# If no <tt>:dependent</tt> option is given, then it will follow the default
# strategy. The default strategy is <tt>:nullify</tt>. This sets the foreign
# keys to <tt>NULL</tt>. For, +has_many+ <tt>:through</tt>, the default
# strategy is +delete_all+.
#
# class Person < ActiveRecord::Base
# has_many :pets # dependent: :nullify option by default
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.delete(Pet.find(1))
# # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]
#
# person.pets.size # => 2
# person.pets
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# Pet.find(1)
# # => #<Pet id: 1, name: "Fancy-Fancy", person_id: nil>
#
# If it is set to <tt>:destroy</tt> all the +records+ are removed by calling
# their +destroy+ method. See +destroy+ for more information.
#
# class Person < ActiveRecord::Base
# has_many :pets, dependent: :destroy
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.delete(Pet.find(1), Pet.find(3))
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.size # => 1
# person.pets
# # => [#<Pet id: 2, name: "Spook", person_id: 1>]
#
# Pet.find(1, 3)
# # => ActiveRecord::RecordNotFound: Couldn't find all Pets with IDs (1, 3)
#
# If it is set to <tt>:delete_all</tt>, all the +records+ are deleted
# *without* calling their +destroy+ method.
#
# class Person < ActiveRecord::Base
# has_many :pets, dependent: :delete_all
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.delete(Pet.find(1))
# # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]
#
# person.pets.size # => 2
# person.pets
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# Pet.find(1)
# # => ActiveRecord::RecordNotFound: Couldn't find Pet with id=1
#
# You can pass +Fixnum+ or +String+ values, it finds the records
# responding to the +id+ and executes delete on them.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.delete("1")
# # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]
#
# person.pets.delete(2, 3)
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
def delete(*records)
@association.delete(*records)
end
# Destroys the +records+ supplied and removes them from the collection.
# This method will _always_ remove record from the database ignoring
# the +:dependent+ option. Returns an array with the removed records.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.destroy(Pet.find(1))
# # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]
#
# person.pets.size # => 2
# person.pets
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.destroy(Pet.find(2), Pet.find(3))
# # => [
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.size # => 0
# person.pets # => []
#
# Pet.find(1, 2, 3) # => ActiveRecord::RecordNotFound: Couldn't find all Pets with IDs (1, 2, 3)
#
# You can pass +Fixnum+ or +String+ values, it finds the records
# responding to the +id+ and then deletes them from the database.
#
# person.pets.size # => 3
# person.pets
# # => [
# # #<Pet id: 4, name: "Benny", person_id: 1>,
# # #<Pet id: 5, name: "Brain", person_id: 1>,
# # #<Pet id: 6, name: "Boss", person_id: 1>
# # ]
#
# person.pets.destroy("4")
# # => #<Pet id: 4, name: "Benny", person_id: 1>
#
# person.pets.size # => 2
# person.pets
# # => [
# # #<Pet id: 5, name: "Brain", person_id: 1>,
# # #<Pet id: 6, name: "Boss", person_id: 1>
# # ]
#
# person.pets.destroy(5, 6)
# # => [
# # #<Pet id: 5, name: "Brain", person_id: 1>,
# # #<Pet id: 6, name: "Boss", person_id: 1>
# # ]
#
# person.pets.size # => 0
# person.pets # => []
#
# Pet.find(4, 5, 6) # => ActiveRecord::RecordNotFound: Couldn't find all Pets with IDs (4, 5, 6)
def destroy(*records)
@association.destroy(*records)
end
# Specifies whether the records should be unique or not.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.select(:name)
# # => [
# # #<Pet name: "Fancy-Fancy">,
# # #<Pet name: "Fancy-Fancy">
# # ]
#
# person.pets.select(:name).distinct
# # => [#<Pet name: "Fancy-Fancy">]
def distinct
@association.distinct
end
alias uniq distinct
# Count all records using SQL.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.count # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
def count(column_name = nil, options = {})
@association.count(column_name, options)
end
# Returns the size of the collection. If the collection hasn't been loaded,
# it executes a <tt>SELECT COUNT(*)</tt> query. Else it calls <tt>collection.size</tt>.
#
# If the collection has been already loaded +size+ and +length+ are
# equivalent. If not and you are going to need the records anyway
# +length+ will take one less query. Otherwise +size+ is more efficient.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.size # => 3
# # executes something like SELECT COUNT(*) FROM "pets" WHERE "pets"."person_id" = 1
#
# person.pets # This will execute a SELECT * FROM query
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
#
# person.pets.size # => 3
# # Because the collection is already loaded, this will behave like
# # collection.size and no SQL count query is executed.
def size
@association.size
end
# Returns the size of the collection calling +size+ on the target.
# If the collection has been already loaded, +length+ and +size+ are
# equivalent. If not and you are going to need the records anyway this
# method will take one less query. Otherwise +size+ is more efficient.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.length # => 3
# # executes something like SELECT "pets".* FROM "pets" WHERE "pets"."person_id" = 1
#
# # Because the collection is loaded, you can
# # call the collection with no additional queries:
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
def length
@association.length
end
# Returns +true+ if the collection is empty. If the collection has been
# loaded or the <tt>:counter_sql</tt> option is provided, it is equivalent
# to <tt>collection.size.zero?</tt>. If the collection has not been loaded,
# it is equivalent to <tt>collection.exists?</tt>. If the collection has
# not already been loaded and you are going to fetch the records anyway it
# is better to check <tt>collection.length.zero?</tt>.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.count # => 1
# person.pets.empty? # => false
#
# person.pets.delete_all
#
# person.pets.count # => 0
# person.pets.empty? # => true
def empty?
@association.empty?
end
# Returns +true+ if the collection is not empty.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.count # => 0
# person.pets.any? # => false
#
# person.pets << Pet.new(name: 'Snoop')
# person.pets.count # => 0
# person.pets.any? # => true
#
# You can also pass a block to define criteria. The behavior
# is the same, it returns true if the collection based on the
# criteria is not empty.
#
# person.pets
# # => [#<Pet name: "Snoop", group: "dogs">]
#
# person.pets.any? do |pet|
# pet.group == 'cats'
# end
# # => false
#
# person.pets.any? do |pet|
# pet.group == 'dogs'
# end
# # => true
def any?(&block)
@association.any?(&block)
end
# Returns true if the collection has more than one record.
# Equivalent to <tt>collection.size > 1</tt>.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.count #=> 1
# person.pets.many? #=> false
#
# person.pets << Pet.new(name: 'Snoopy')
# person.pets.count #=> 2
# person.pets.many? #=> true
#
# You can also pass a block to define criteria. The
# behavior is the same, it returns true if the collection
# based on the criteria has more than one record.
#
# person.pets
# # => [
# # #<Pet name: "Gorby", group: "cats">,
# # #<Pet name: "Puff", group: "cats">,
# # #<Pet name: "Snoop", group: "dogs">
# # ]
#
# person.pets.many? do |pet|
# pet.group == 'dogs'
# end
# # => false
#
# person.pets.many? do |pet|
# pet.group == 'cats'
# end
# # => true
def many?(&block)
@association.many?(&block)
end
# Returns +true+ if the given object is present in the collection.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets # => [#<Pet id: 20, name: "Snoop">]
#
# person.pets.include?(Pet.find(20)) # => true
# person.pets.include?(Pet.find(21)) # => false
def include?(record)
@association.include?(record)
end
def proxy_association
@association
end
# We don't want this object to be put on the scoping stack, because
# that could create an infinite loop where we call an @association
# method, which gets the current scope, which is this object, which
# delegates to @association, and so on.
def scoping
@association.scope.scoping { yield }
end
# Returns a <tt>Relation</tt> object for the records in this association
def scope
association = @association
@association.scope.extending! do
define_method(:proxy_association) { association }
end
end
# :nodoc:
alias spawn scope
# Equivalent to <tt>Array#==</tt>. Returns +true+ if the two arrays
# contain the same number of elements and if each element is equal
# to the corresponding element in the other array, otherwise returns
# +false+.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>
# # ]
#
# other = person.pets.to_ary
#
# person.pets == other
# # => true
#
# other = [Pet.new(id: 1), Pet.new(id: 2)]
#
# person.pets == other
# # => false
def ==(other)
load_target == other
end
# Returns a new array of objects from the collection. If the collection
# hasn't been loaded, it fetches the records from the database.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets
# # => [
# # #<Pet id: 4, name: "Benny", person_id: 1>,
# # #<Pet id: 5, name: "Brain", person_id: 1>,
# # #<Pet id: 6, name: "Boss", person_id: 1>
# # ]
#
# other_pets = person.pets.to_ary
# # => [
# # #<Pet id: 4, name: "Benny", person_id: 1>,
# # #<Pet id: 5, name: "Brain", person_id: 1>,
# # #<Pet id: 6, name: "Boss", person_id: 1>
# # ]
#
# other_pets.replace([Pet.new(name: 'BooGoo')])
#
# other_pets
# # => [#<Pet id: nil, name: "BooGoo", person_id: 1>]
#
# person.pets
# # This is not affected by replace
# # => [
# # #<Pet id: 4, name: "Benny", person_id: 1>,
# # #<Pet id: 5, name: "Brain", person_id: 1>,
# # #<Pet id: 6, name: "Boss", person_id: 1>
# # ]
def to_ary
load_target.dup
end
alias_method :to_a, :to_ary
# Adds one or more +records+ to the collection by setting their foreign keys
# to the association's primary key. Returns +self+, so several appends may be
# chained together.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets.size # => 0
# person.pets << Pet.new(name: 'Fancy-Fancy')
# person.pets << [Pet.new(name: 'Spook'), Pet.new(name: 'Choo-Choo')]
# person.pets.size # => 3
#
# person.id # => 1
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]
def <<(*records)
proxy_association.concat(records) && self
end
alias_method :push, :<<
alias_method :append, :<<
def prepend(*args)
raise NoMethodError, "prepend on association is not defined. Please use << or append"
end
# Equivalent to +delete_all+. The difference is that returns +self+, instead
# of an array with the deleted objects, so methods can be chained. See
# +delete_all+ for more information.
def clear
delete_all
self
end
# Reloads the collection from the database. Returns +self+.
# Equivalent to <tt>collection(true)</tt>.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
# person.pets # fetches pets from the database
# # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
#
# person.pets # uses the pets cache
# # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
#
# person.pets.reload # fetches pets from the database
# # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
#
# person.pets(true) # fetches pets from the database
# # => [#<Pet id: 1, name: "Snoop", group: "dogs", person_id: 1>]
def reload
proxy_association.reload
self
end
end
end
end
|